Anticonvulsant effects of desvenlafaxine on modulating brain monoamine and oxidative stress in mice

Abstract Desvenlafaxine succinate (DVS) inhibits serotonin reuptake selectively and is approved for major depressive disorders. This research investigated influence of DVS on modulating brain monoamine and oxidative stress in mice. The antiepileptic potential of DVS (10, 20, or 30 mg/kg/i.p.) in pentylenetetrazole (PTZ; 85 mg/kg) with i.p. route of administration, strychnine (STR; 75 mg/kg) with i.p. route, pilocarpine (400 mg/kg) with s.c. route and maximal electroshock MES-induced convulsion in mouse models. The activities of oxidative stress, i.e. superoxide dismutase (SOD), glutathione (GSH) and lipid peroxidation (LPO) as well as gamma-aminobutyric acid (GABA) in the brains of PTZ-induced convulsive mice. Treatment with DVS increased the latency to develop siezures and declined mortalities in rodents against PTZ, STR and pilocarpine-induced convulsions. Results of MES-leaded siezures revealed that DVS reduced tonic hind limb extension duration and mortalities significantly. Brain, SOD, GSH and GABA level were significantly (P 0.01) increased and LPO reduced significantly (P 0.01) after DVS treatment. Furthermore, the DVS did not show any motor coordination signs in the rotarod test. We demonstrated that the role of DVS in convulsion genesis in mice under control condition and attenuate the PTZ-induced oxidative damage.

Resumo O succinato de desvenlafaxina (DVS) inibe seletivamente a recaptação da serotonina e é aprovado para transtornos depressivos maiores. Esta pesquisa investigou a influência do DVS na modulação da monoamina cerebral e do estresse oxidativo em camundongos. O potencial antiepiléptico de DVS (10, 20 ou 30 mg / kg / i.p.) Em pentilenotetrazole (PTZ; 85 mg / kg) com i.p. via de administração, estricnina (STR; 75 mg / kg) com i.p. via, pilocarpina (400 mg / kg) com s.c. rota e convulsão induzida por MES de eletrochoque máximo em modelos de camundongos. As atividades de estresse oxidativo, ou seja, superóxido dismutase (SOD), glutationa (GSH) e peroxidação lipídica (LPO), bem como ácido gama-aminobutírico (GABA) nos cérebros de camundongos convulsivos induzidos por PTZ. O tratamento com DVS aumentou a latência para desenvolver crises e diminuiu a mortalidade em roedores contra convulsões induzidas por PTZ, STR e pilocarpina. Os resultados de siezures conduzidos por MES revelaram que o DVS reduziu significativamente a duração e a mortalidade da extensão tônica dos membros posteriores. Os níveis de cérebro, SOD, GSH e GABA aumentaram significativamente (P 0,01) e o LPO reduziu significativamente (P 0,01) após o tratamento com DVS. Além disso, o DVS não apresentou sinais de coordenação motora no teste do rotarod. Demonstramos o papel do DVS na gênese da convulsão em camundongos sob condição de controle e atenua o dano oxidativo induzido por PTZ.

Anticonvulsant effects of desvenlafaxine on modulating brain monoamine and oxidative stress in mice / Efeitos anticonvulsivantes da desvenlafaxina na modulação da monoamina cerebral e do estresse oxidativo em camundongos

Desvenlafaxine succinate (DVS) inhibits serotonin reuptake selectively and is approved for major depressive disorders. This research investigated influence of DVS on modulating brain monoamine and oxidative stress in mice. The antiepileptic potential of DVS (10, 20, or 30 mg/kg/i.p.) in pentylenetetrazole (PTZ; 85 mg/kg) with i.p. route of administration, strychnine (STR; 75 mg/kg) with i.p. route, pilocarpine (400 mg/kg) with s.c. route and maximal electroshock MES-induced convulsion in mouse models. The activities of oxidative stress, i.e. superoxide dismutase (SOD), glutathione (GSH) and lipid peroxidation (LPO) as well as gamma-aminobutyric acid (GABA) in the brains of PTZ-induced convulsive mice. Treatment with DVS increased the latency to develop siezures and declined mortalities in rodents against PTZ, STR and pilocarpine-induced convulsions. Results of MES-leaded siezures revealed that DVS reduced tonic hind limb extension duration and mortalities significantly. Brain, SOD, GSH and GABA level were significantly (P<0.01) increased and LPO reduced significantly (P<0.01) after DVS treatment. Furthermore, the DVS did not show any motor coordination signs in the rotarod test. We demonstrated that the role of DVS in convulsion genesis in mice under control condition and attenuate the PTZ-induced oxidative damage.

O succinato de desvenlafaxina (DVS) inibe seletivamente a recaptação da serotonina e é aprovado para transtornos depressivos maiores. Esta pesquisa investigou a influência do DVS na modulação da monoamina cerebral e do estresse oxidativo em camundongos. O potencial antiepiléptico de DVS (10, 20 ou 30 mg / kg / i.p.) Em pentilenotetrazole (PTZ; 85 mg / kg) com i.p. via de administração, estricnina (STR; 75 mg / kg) com i.p. via, pilocarpina (400 mg / kg) com s.c. rota e convulsão induzida por MES de eletrochoque máximo em modelos de camundongos. As atividades de estresse oxidativo, ou seja, superóxido dismutase (SOD), glutationa (GSH) e peroxidação lipídica (LPO), bem como ácido gama-aminobutírico (GABA) nos cérebros de camundongos convulsivos induzidos por PTZ. O tratamento com DVS aumentou a latência para desenvolver crises e diminuiu a mortalidade em roedores contra convulsões induzidas por PTZ, STR e pilocarpina. Os resultados de siezures conduzidos por MES revelaram que o DVS reduziu significativamente a duração e a mortalidade da extensão tônica dos membros posteriores. Os níveis de cérebro, SOD, GSH e GABA aumentaram significativamente (P < 0,01) e o LPO reduziu significativamente (P < 0,01) após o tratamento com DVS. Além disso, o DVS não apresentou sinais de coordenação motora no teste do rotarod. Demonstramos o papel do DVS na gênese da convulsão em camundongos sob condição de controle e atenua o dano oxidativo induzido por PTZ.

Anticonvulsant effects of desvenlafaxine on modulating brain monoamine and oxidative stress in mice / Efeitos anticonvulsivantes da desvenlafaxina na modulação da monoamina cerebral e do estresse oxidativo em camundongos

Desvenlafaxine succinate (DVS) inhibits serotonin reuptake selectively and is approved for major depressive disorders. This research investigated influence of DVS on modulating brain monoamine and oxidative stress in mice. The antiepileptic potential of DVS (10, 20, or 30 mg/kg/i.p.) in pentylenetetrazole (PTZ; 85 mg/kg) with i.p. route of administration, strychnine (STR; 75 mg/kg) with i.p. route, pilocarpine (400 mg/kg) with s.c. route and maximal electroshock MES-induced convulsion in mouse models. The activities of oxidative stress, i.e. superoxide dismutase (SOD), glutathione (GSH) and lipid peroxidation (LPO) as well as gamma-aminobutyric acid (GABA) in the brains of PTZ-induced convulsive mice. Treatment with DVS increased the latency to develop siezures and declined mortalities in rodents against PTZ, STR and pilocarpine-induced convulsions. Results of MES-leaded siezures revealed that DVS reduced tonic hind limb extension duration and mortalities significantly. Brain, SOD, GSH and GABA level were significantly (P<0.01) increased and LPO reduced significantly (P<0.01) after DVS treatment. Furthermore, the DVS did not show any motor coordination signs in the rotarod test. We demonstrated that the role of DVS in convulsion genesis in mice under control condition and attenuate the PTZ-induced oxidative damage.(AU)

O succinato de desvenlafaxina (DVS) inibe seletivamente a recaptação da serotonina e é aprovado para transtornos depressivos maiores. Esta pesquisa investigou a influência do DVS na modulação da monoamina cerebral e do estresse oxidativo em camundongos. O potencial antiepiléptico de DVS (10, 20 ou 30 mg / kg / i.p.) Em pentilenotetrazole (PTZ; 85 mg / kg) com i.p. via de administração, estricnina (STR; 75 mg / kg) com i.p. via, pilocarpina (400 mg / kg) com s.c. rota e convulsão induzida por MES de eletrochoque máximo em modelos de camundongos. As atividades de estresse oxidativo, ou seja, superóxido dismutase (SOD), glutationa (GSH) e peroxidação lipídica (LPO), bem como ácido gama-aminobutírico (GABA) nos cérebros de camundongos convulsivos induzidos por PTZ. O tratamento com DVS aumentou a latência para desenvolver crises e diminuiu a mortalidade em roedores contra convulsões induzidas por PTZ, STR e pilocarpina. Os resultados de siezures conduzidos por MES revelaram que o DVS reduziu significativamente a duração e a mortalidade da extensão tônica dos membros posteriores. Os níveis de cérebro, SOD, GSH e GABA aumentaram significativamente (P < 0,01) e o LPO reduziu significativamente (P < 0,01) após o tratamento com DVS. Além disso, o DVS não apresentou sinais de coordenação motora no teste do rotarod. Demonstramos o papel do DVS na gênese da convulsão em camundongos sob condição de controle e atenua o dano oxidativo induzido por PTZ.(AU)

Sexual motivation and performance in sexual naïve and experienced rats treated with ivermectin: an ultrasonic vocalization study / Motivação e desempenho sexual em ratos com e sem experiência sexual tratados com ivermectina: um estudo da vocalização ultrassônica

In mammals, ivermectin acts as a GABAA receptor agonist and stimulates GABA release. Previous studies showed that ivermectin (IVM) reduces sexual performance, impairing the latency to the first mount and intromission. These parameters are usually considered motivational parameters of sexual behavior. However, IVM increases GABAergic activity leading to motor incoordination. Thus, it is reasonable to propose that IVM affects sexual performance via motor incoordination pathways. The present study analyzed ultrasonic vocalization in rats to verify whether IVM impairs sexual behavior via motivational mechanisms or motor impairment. Because sexual experience attenuates the impairment of motor performance, rats with sexual experience were also studied. Sexually naive and experienced rats were administered a therapeutic IVM dose and saline. The rats were exposed to receptive females, and the latency to the first mount was evaluated, followed by the 50-kHz USV test. IVM treatment in naïve rats increased the latency to first to mount relative to Saline naïve rats, while no differences were observed between saline and experienced rats. In naïve-IVM rats, a reduced frequency and total calls and increased mean time of calls occur relative to SAL-naïve rats. Experienced IVM rats did not show differences in the frequency, mean, and maximal calls close to Saline experienced rats. However, an increase in the total calls and the dominant frequency of calls were observed in IVM-experienced rats compared to Saline experienced rats. A negative and positive correlation occurred between the latency to the first mount and USVs in groups with and without ivermectin exposure. Hence, we propose that ivermectin increased the sexual motivation of rats exposed to a female in estrous based in USVs despite an increased latency to the first mount that occurred. The increased latency to the first mount resulted from motor incoordination, as previously observed and proposed by our group.(AU)

Em mamíferos, a ivermectina (IVM) atua como agonista do receptor GABAA e estimula a liberação de GABA. Estudos anteriores mostraram que a IVM reduz o desempenho sexual, prejudicando a latência para a primeira monta e intromissão. Esses parâmetros são geralmente considerados parâmetros motivacionais do comportamento sexual. Por outro lado, a IVM aumenta a atividade GABAérgica levando à incoordenação motora. Assim, é possível que a IVM afete o desempenho sexual devido a um impedimento motor. O presente estudo analisou a vocalização ultrassônica em ratos para verificar se a IVM prejudica o comportamento sexual via mecanismos motivacionais ou comprometimento motor. Uma vez que a experiência sexual atenua o comprometimento do desempenho motor, também foram estudados ratos com experiência sexual. Ratos sexualmente inexperientes e experientes foram administrados com uma dose terapêutica de IVM ou solução salina IVM. Os ratos foram expostos a fêmeas receptivas e foi avaliada a latência para a primeira monta, seguida do teste de vocalização ultrassônica (USV) de 50 kHz. O tratamento com IVM em ratos inexperientes aumentou a latência para a primeira monta em relação a ratos inexperientes tratados com solução salina, enquanto não foram observadas diferenças entre ratos experientes tratados com IVM e solução salina. Em ratos inexperientes tratados com IVM ocorreu redução da frequência e total de USVs, bem como aumento do tempo médio de USVs em relação aos ratos sem experiência. Ratos experientes tratados com IVM não mostraram diferenças na frequência, média e máxima das USVs em relação aos ratos experientes tratados com solução salina; no entanto, observou-se aumento no total de USVs e na frequência dominante de USVS em ratos experientes tratados com IVM comparados aos experientes tratados com solução salina. Observou-se correlação negativa e positiva entre a latência para a primeira monta e USVs nos grupos sem e com experiência tratados com IVM, respectivamente. Assim, propomos que a IVM aumentou a motivação sexual de ratos expostos a uma fêmea em estro com base em USVs, apesar de apresentar aumento na latência para a primeira monta. O aumento da latência para a primeira monta foi atribuída à incoordenação motora, conforme observado anteriormente e proposto por nosso grupo.(AU)

Clomipramine and alprazolam to treat noise phobia in a dog: case report / Uso de clomipramina e alprazolam no tratamento de cão com sensibilidade à ruídos: relato de caso

Behavioral disorders, including noise phobia, have a great impact on small animals internal medicine, impairing their quality of life as well as their life expectancy. The objective of this work is to report the case of a male dog who suffered from noise phobia and panic attacks triggered by thunderstorms and fireworks, and did not respond to previous training and treatment. After clinical and laboratory evaluations, he was treated with 2mg/kg clomipramine twice daily for 90 days associated with 0.06mg/kg alprazolam as needed on those days of intense fear. During the first week of treatment, a significant improvement could already be observed, with reduction in destructive behaviors, which lingered on for up to eight months of follow-up. The treatment stabilized the clinical condition and improved the patient’s quality of life.

Os distúrbios de comportamento, entre eles o medo de ruídos, apresentam um grande impacto na clínica de peque-nos animais, acarretando em decréscimo na qualidade e expectativa de vida. O objetivo deste trabalho é relatar o caso de um cão, macho, com histórico de medo de ruídos, que apresentava quadros de pânico desencadeados por trovões e fogos de arti-fício, sendo refratário a tentativas prévias de adestramento e tratamento medicamentoso. Após avaliação clínica e laboratorial, instituiu-se tratamento com clomipramina 2mg/kg BID durante 90 dias associada à administração de alprazolam 0,06mg/kg conforme necessário nos dias de medo intensificado. Na primeira semana de tratamento observou-se melhora significativa, com redução dos comportamentos destrutivos, se estendendo até 8 meses de acompanhamento. O tratamento realizado proporcio-nou estabilização do quadro clínico e incremento na qualidade de vida do paciente. informação a ser inserida pelos autores.

Clomipramine and alprazolam to treat noise phobia in a dog: case report / Uso de clomipramina e alprazolam no tratamento de cão com sensibilidade à ruídos: relato de caso

Behavioral disorders, including noise phobia, have a great impact on small animals internal medicine, impairing their quality of life as well as their life expectancy. The objective of this work is to report the case of a male dog who suffered from noise phobia and panic attacks triggered by thunderstorms and fireworks, and did not respond to previous training and treatment. After clinical and laboratory evaluations, he was treated with 2mg/kg clomipramine twice daily for 90 days associated with 0.06mg/kg alprazolam as needed on those days of intense fear. During the first week of treatment, a significant improvement could already be observed, with reduction in destructive behaviors, which lingered on for up to eight months of follow-up. The treatment stabilized the clinical condition and improved the patients quality of life.(AU)

Os distúrbios de comportamento, entre eles o medo de ruídos, apresentam um grande impacto na clínica de peque-nos animais, acarretando em decréscimo na qualidade e expectativa de vida. O objetivo deste trabalho é relatar o caso de um cão, macho, com histórico de medo de ruídos, que apresentava quadros de pânico desencadeados por trovões e fogos de arti-fício, sendo refratário a tentativas prévias de adestramento e tratamento medicamentoso. Após avaliação clínica e laboratorial, instituiu-se tratamento com clomipramina 2mg/kg BID durante 90 dias associada à administração de alprazolam 0,06mg/kg conforme necessário nos dias de medo intensificado. Na primeira semana de tratamento observou-se melhora significativa, com redução dos comportamentos destrutivos, se estendendo até 8 meses de acompanhamento. O tratamento realizado proporcio-nou estabilização do quadro clínico e incremento na qualidade de vida do paciente. informação a ser inserida pelos autores.(AU)

Effects of Heat Stress on the Development of GABAergic Neurons in the HPG Axis of Wenchang Chicks

This study conducted an in-depth investigation on the development of GABAergic neurons and their receptors in HPG axis-related target organs of Wenchang chicks under heat stress. One-day-old healthy Wenchang chicks were randomly divided into control (CK) and heat stress (HS) groups. Chicks in the HS group were placed in a 40±0.5°C climatic chamber for HS treatment from 13:00 to 15:00 daily. By immunohistochemistry and Western blotting, GABA and GABAA receptor (GABAAR) expression in the hypothalamus of the HS group was significantly higher (p 0.05), but GABAB receptor (GABABR) expression was significantly lower than that of the CK group (p 0.05). Expression of GABA and its two receptors in the pituitary tissues of the HS group was significantly lower than in the CK group (p 0.05). Expression of GABA and GABABR in ovaries in the HS group was significantly higher, but expression of GABAAR in the testes of the HS group was lower than that of the CK group (p 0.05). In the male chicks, expression of GABA and its two receptors in the hypothalamus, pituitary, and testicular tissues of the HS group was significantly higher than that of the CK group (p 0.05). Western blotting showed that the GABAAR and GABABR expression of the HS group was significantly higher than that of the CK group at 3 and 5 weeks of age. Thus, HS caused GABAergic nervous system disorder in the HPG axis of Wenchang chicks and seriously hindered the normal development of GABAergic neurons in chicks, leading to the disorder of the expression of GABA and its receptors in tissues.(AU)

Effects of Heat Stress on the Development of GABAergic Neurons in the HPG Axis of Wenchang Chicks

This study conducted an in-depth investigation on the development of GABAergic neurons and their receptors in HPG axis-related target organs of Wenchang chicks under heat stress. One-day-old healthy Wenchang chicks were randomly divided into control (CK) and heat stress (HS) groups. Chicks in the HS group were placed in a 40±0.5°C climatic chamber for HS treatment from 13:00 to 15:00 daily. By immunohistochemistry and Western blotting, GABA and GABAA receptor (GABAAR) expression in the hypothalamus of the HS group was significantly higher (p 0.05), but GABAB receptor (GABABR) expression was significantly lower than that of the CK group (p 0.05). Expression of GABA and its two receptors in the pituitary tissues of the HS group was significantly lower than in the CK group (p 0.05). Expression of GABA and GABABR in ovaries in the HS group was significantly higher, but expression of GABAAR in the testes of the HS group was lower than that of the CK group (p 0.05). In the male chicks, expression of GABA and its two receptors in the hypothalamus, pituitary, and testicular tissues of the HS group was significantly higher than that of the CK group (p 0.05). Western blotting showed that the GABAAR and GABABR expression of the HS group was significantly higher than that of the CK group at 3 and 5 weeks of age. Thus, HS caused GABAergic nervous system disorder in the HPG axis of Wenchang chicks and seriously hindered the normal development of GABAergic neurons in chicks, leading to the disorder of the expression of GABA and its receptors in tissues.

Aspectos clínico-patológicos da intoxicação por ivermectina em suínos / Clinical and pathological aspects of the intoxication by ivermectin in pigs

A ivermectina é um derivado semi-sintético das avermectinas. Essas lactonas macrocíclicas são obtidas como compostos da fermentação do actinomiceto Streptomyces avermitilis, apesar de sua ampla margem de segurança, casos de intoxicação iatrogênica tem sido observados em diversas espécies animais. O objetivo do presente trabalho é relatar o primeiro surto de intoxicação por ivermectina em suínos no Brasil. Os casos descritos neste estudo foram observados em uma propriedade rural no Município de Catingueira, Estado da Paraíba. O rebanho era composto por 103 suínos, destes 32 foram medicados com ivermectina a 1% por via subcutânea para tratamento de ecto e endoparasitose. A dose utilizada foi cinco vezes superior a recomendada para espécie. Os animais apresentaram anorexia, tremores, ataxia, paresia dos membros posteriores, depressão, coma e morte. 96,9% dos animais evoluiram a óbito. Os sinais clínicos foram observados em média oito horas após administração do fármaco e o período de evolução que culminou com o óbito variou de 10 a 48 horas. O presente estudo chama atenção para a necessidade de se calcular com precisão a dose de ivermectina a ser utilizada em suínos, em especial para animais jovens, uma vez que é possível que nos mesmos a barreira hematoencafálica seja mais permeável ao fármaco em relação aos adultos.(AU)

Ivermectin is a semi-synthetic derivative of avermectins. These macrocyclic lactones are obtained as fermentation compounds of the actinomycete Streptomyces avermitilis, despite their wide safety margin, cases of iatrogenic intoxication have been observed in several animal species. The objective of the present study is to report the first outbreak of ivermectin intoxication in swine in Brazil. The cases described in this study were observed in a rural property in the Municipality of Catingueira, State of Paraíba. The herd was composed of 103 pigs, of these 32 were medicated with 1% ivermectin subcutaneously for treatment of ecto and endoparasitosis. The dose used was five times higher than that recommended for the species. The animals presented anorexia, tremors, ataxia, paresis of the hind limbs, depression, coma and death. 96.9% of the animals evolved to death. Clinical signs were observed on average eight hours after drug administration and the evolution period that culminated with death ranged from 10 to 48 hours. The present study draws attention to the need to accurately calculate the dose of ivermectin to be used in pigs, especially for young animals, since it is possible that the blood-brain barrier is more permeable to the drug compared to adults.(AU)

Ivermectin reduces sexual dimorphism in behavioral models of exploration, anxiety and depression in C57BL/6 mice / A ivermectina reduz o dimorfismo sexual em modelos comportamentais de exploração, ansiedade e depressão de camundongos C57BL/6

Avermectins and milbemycins, often also referred as macrocyclic lactones, are the most used antiparasitic medicines in the world and are widely employed in veterinary medicine, agriculture and human medicine. The objective of this work was to evaluate the sexually dimorphic effects of ivermectin (IVM) in C57BL/6 mice in animal models linked to emotionality. For this, male and female mice were treated with two therapeutic doses of IVM (0.2 or 1.0 mg / kg) or 0.9% saline solution. Twenty-four hours after treatments the mice were observed in open field, elevated plus maze and tail suspension test. The results showed that, in relation to the male mice: 1) ivermectin, in both doses, prevented the sexual dimorphism in the frequency of locomotion and reduced, in females, the frequency of rearing and the time of immobility; 2) in the elevated plus maze, females showed increase in the open arm time and in risk behavior and reduction in the frequency of entries in the closed arm; 3) in the tail suspension test, IVM prevented the expression of sexual dimorphism. It was concluded that in the open field, elevated plus maze and tail suspension ivermectin produces sexually dimorphic effects in C57BL/6 mice. The most prominent effects of ivermectin occurred in females.

As avermectinas e as milbemicinas, muitas vezes também referidas como lactonas macrocíclicas, são os medicamentos antiparasitários mais vendidos no mundo, sendo amplamente utilizados na medicina veterinária, na agricultura e em medicina humana. O objetivo deste trabalho foi o de avaliar os efeitos sexualmente dimórficos da ivermectina (IVM) em camundongos C57BL/6 em modelos animais ligados à emocionalidade. Para tanto, os camundongos machos e fêmeas foram tratados com duas doses terapêuticas da IVM (0,2 ou 1,0 mg/kg) ou solução salina a 0,9%. Vinte e quatro horas após estes tratamentos, foram observados em campo aberto, no labirinto em cruz elevada e no teste de suspensão da cauda. Os resultados mostraram que, em relação aos camundongos machos: 1) a ivermectina, nas duas doses, impediu o dimorfismo sexual na frequência de locomoção e reduziu, em fêmeas, a frequência de levantar e o tempo de imobilidade; 2) no labirinto em cruz elevada, as fêmeas mostraram aumento no tempo de braço aberto e no comportamento de risco e redução na frequência de entradas no braço fechado; 3) no teste de suspensão da cauda a ivermectina impediu a expressão do dimorfismo sexual. Concluiu-se que, nos modelos atividade geral em campo aberto, labirinto em cruz elevada e suspensão da cauda, a ivermectina produz efeitos sexualmente dimórficos em camundongos C57BL/6. Os efeitos mais proeminentes da ivermectina ocorreram em fêmeas.

Ivermectin reduces sexual dimorphism in behavioral models of exploration, anxiety and depression in C57BL/6 mice / A ivermectina reduz o dimorfismo sexual em modelos comportamentais de exploração, ansiedade e depressão de camundongos C57BL/6

Avermectins and milbemycins, often also referred as macrocyclic lactones, are the most used antiparasitic medicines in the world and are widely employed in veterinary medicine, agriculture and human medicine. The objective of this work was to evaluate the sexually dimorphic effects of ivermectin (IVM) in C57BL/6 mice in animal models linked to emotionality. For this, male and female mice were treated with two therapeutic doses of IVM (0.2 or 1.0 mg / kg) or 0.9% saline solution. Twenty-four hours after treatments the mice were observed in open field, elevated plus maze and tail suspension test. The results showed that, in relation to the male mice: 1) ivermectin, in both doses, prevented the sexual dimorphism in the frequency of locomotion and reduced, in females, the frequency of rearing and the time of immobility; 2) in the elevated plus maze, females showed increase in the open arm time and in risk behavior and reduction in the frequency of entries in the closed arm; 3) in the tail suspension test, IVM prevented the expression of sexual dimorphism. It was concluded that in the open field, elevated plus maze and tail suspension ivermectin produces sexually dimorphic effects in C57BL/6 mice. The most prominent effects of ivermectin occurred in females.(AU)

As avermectinas e as milbemicinas, muitas vezes também referidas como lactonas macrocíclicas, são os medicamentos antiparasitários mais vendidos no mundo, sendo amplamente utilizados na medicina veterinária, na agricultura e em medicina humana. O objetivo deste trabalho foi o de avaliar os efeitos sexualmente dimórficos da ivermectina (IVM) em camundongos C57BL/6 em modelos animais ligados à emocionalidade. Para tanto, os camundongos machos e fêmeas foram tratados com duas doses terapêuticas da IVM (0,2 ou 1,0 mg/kg) ou solução salina a 0,9%. Vinte e quatro horas após estes tratamentos, foram observados em campo aberto, no labirinto em cruz elevada e no teste de suspensão da cauda. Os resultados mostraram que, em relação aos camundongos machos: 1) a ivermectina, nas duas doses, impediu o dimorfismo sexual na frequência de locomoção e reduziu, em fêmeas, a frequência de levantar e o tempo de imobilidade; 2) no labirinto em cruz elevada, as fêmeas mostraram aumento no tempo de braço aberto e no comportamento de risco e redução na frequência de entradas no braço fechado; 3) no teste de suspensão da cauda a ivermectina impediu a expressão do dimorfismo sexual. Concluiu-se que, nos modelos atividade geral em campo aberto, labirinto em cruz elevada e suspensão da cauda, a ivermectina produz efeitos sexualmente dimórficos em camundongos C57BL/6. Os efeitos mais proeminentes da ivermectina ocorreram em fêmeas.(AU)

General anesthesia in geriatric dogs with propofol-isoflurane, propofolsevoflurane, alphaxalone-isoflurane, alphaxalone-sevoflurane and their comparison of biochemical, hemodynamic and cardiopulmonary effects

Background: Geriatric is defined as the life-cycle in which the physical state, organ functions, sensory functions, mental function and immunity progressively regress. Aging causes progressive and irreversible changes in the functional capacities of organ systems, which in turn alter the response to stress and anesthetic drugs. Propofol is an anesthetic agent with sedative and hypnotic effects. Anesthesia induction with propofol is fast and smooth. Alphaxalone (3α-hydroxy-5α-pregnane11,20-dione) is a central nervous system depressant in the form of synthetic neuroactive steroids. This allows anesthesia and muscle relaxation by increasing the inhibition of gamma amino butyric acid type A (GABA) receptors. The aim of this study is to compare effects of propofol-isoflurane and propofol-sevoflurane with relatively a new anesthetic combination alphaxalone-isoflurane and alphaxalone-sevoflurane on hematological, biochemical and physiological parameters.Materials, Methods & Results: Dogs were randomly divided into 4 groups and anesthesia protocols were applied. After induction of anesthesia with 6 mg/kg propofol in groups 1 and 2, isoflurane anesthesia was continued in group 1 and sevoflurane in group 2. After induction of 3 mg/kg alphaxalone anesthesia in groups 3 and 4, isoflurane anesthesia was continued in group 3 whereas sevoflurane in group 4. Vena cephalica was catheterized for blood collection. At the preanesthetic period, 15, 30, 45, 60 min and 60 min after the anesthesia, complete blood counts were performed. Serum ALT, AST, urea, creatinine values were measured during preanesthesia, perianesthesia 15-30 min and 60 min after anesthesia. Cardiopulmonary parameters and reflexes were evaluated before anesthesia and recorded at perianesthetic 5, 10, 15, 30, 45, 60 min and 60 min after full recovery. Patients were monitored during anesthesia. The average age of the dogs in the study was 10.83.[...]

General anesthesia in geriatric dogs with propofol-isoflurane, propofolsevoflurane, alphaxalone-isoflurane, alphaxalone-sevoflurane and their comparison of biochemical, hemodynamic and cardiopulmonary effects

Background: Geriatric is defined as the life-cycle in which the physical state, organ functions, sensory functions, mental function and immunity progressively regress. Aging causes progressive and irreversible changes in the functional capacities of organ systems, which in turn alter the response to stress and anesthetic drugs. Propofol is an anesthetic agent with sedative and hypnotic effects. Anesthesia induction with propofol is fast and smooth. Alphaxalone (3α-hydroxy-5α-pregnane11,20-dione) is a central nervous system depressant in the form of synthetic neuroactive steroids. This allows anesthesia and muscle relaxation by increasing the inhibition of gamma amino butyric acid type A (GABA) receptors. The aim of this study is to compare effects of propofol-isoflurane and propofol-sevoflurane with relatively a new anesthetic combination alphaxalone-isoflurane and alphaxalone-sevoflurane on hematological, biochemical and physiological parameters.Materials, Methods & Results: Dogs were randomly divided into 4 groups and anesthesia protocols were applied. After induction of anesthesia with 6 mg/kg propofol in groups 1 and 2, isoflurane anesthesia was continued in group 1 and sevoflurane in group 2. After induction of 3 mg/kg alphaxalone anesthesia in groups 3 and 4, isoflurane anesthesia was continued in group 3 whereas sevoflurane in group 4. Vena cephalica was catheterized for blood collection. At the preanesthetic period, 15, 30, 45, 60 min and 60 min after the anesthesia, complete blood counts were performed. Serum ALT, AST, urea, creatinine values were measured during preanesthesia, perianesthesia 15-30 min and 60 min after anesthesia. Cardiopulmonary parameters and reflexes were evaluated before anesthesia and recorded at perianesthetic 5, 10, 15, 30, 45, 60 min and 60 min after full recovery. Patients were monitored during anesthesia. The average age of the dogs in the study was 10.83.[...](AU)

Effects of gaba on the thymus cytokines of wenchang chickens submitted to heat stress

Under routine feeding conditions, 1-day-old male chicks were randomly divided into control group (CK), heat-stress group (HS), and GABA + heat stress group (GABA+HS). The thymus contents of IL-1, IL-2, TGF-1, IFN-, GH and HSP70 were determined by enzyme-linked immunosorbent assays. The results showed that: (1) IL-1 and TGF-1 contents of HS group were significantly lower than those of the CK group (p 0.05), and those of the GABA+HS group were significantly higher relative to the HS group (p 0.05); (2) IL-2 and IFN- contents of the HS group were significantly higher than those of the CK group (p 0.05), and those of the GABA+HS group were significantly lower relative to the HS group (p 0.05);(3) the thymus GH content of all three groups first increased and then decreased. The expression levels GH of the HS and GABA+HS groups were significantly lower than CK group (p 0.05); and (4) HSP70 expression levels in the thymus were significantly higher in the HS and GABA+HS groups relative to the CK group (p 0.05). These results indicate that heat stress affected thymus development, immune functions, and overall growth of chickens. Furthermore, it was shown that feeding GABA may significantly improve the immune responses of heat-stressed chickens by increasing the expression levels of IL-1 and TGF-1, and effectively alleviate the negative effects of heat stress on thymus development by changing HSP70 expression and GH secretion.

Effects of gaba on the thymus cytokines of wenchang chickens submitted to heat stress

Under routine feeding conditions, 1-day-old male chicks were randomly divided into control group (CK), heat-stress group (HS), and GABA + heat stress group (GABA+HS). The thymus contents of IL-1, IL-2, TGF-1, IFN-, GH and HSP70 were determined by enzyme-linked immunosorbent assays. The results showed that: (1) IL-1 and TGF-1 contents of HS group were significantly lower than those of the CK group (p 0.05), and those of the GABA+HS group were significantly higher relative to the HS group (p 0.05); (2) IL-2 and IFN- contents of the HS group were significantly higher than those of the CK group (p 0.05), and those of the GABA+HS group were significantly lower relative to the HS group (p 0.05);(3) the thymus GH content of all three groups first increased and then decreased. The expression levels GH of the HS and GABA+HS groups were significantly lower than CK group (p 0.05); and (4) HSP70 expression levels in the thymus were significantly higher in the HS and GABA+HS groups relative to the CK group (p 0.05). These results indicate that heat stress affected thymus development, immune functions, and overall growth of chickens. Furthermore, it was shown that feeding GABA may significantly improve the immune responses of heat-stressed chickens by increasing the expression levels of IL-1 and TGF-1, and effectively alleviate the negative effects of heat stress on thymus development by changing HSP70 expression and GH secretion.(AU)

Involvement of Gaba and Cannabinoid Receptors in Central Food Intake Regulation in Neonatal Layer Chicks: Role of CB1 and Gabaa Receptors

Feeding behavior is regulated via a complex network which interacts via diverse signals from central and peripheral tissues. Endocannabinoids modulate release of GABA in a variety of regions of the central nervous system. Endocannabinoids and GABAergic system have an important role in the central regulation of appetite. Thus, the present study examines the possible interaction of central canabinoidergic and GABAergic systems on food intake in 3-h food-deprived (FD3) neonatal layer-type chicks. The results of this study showed that intracerebroventricular (ICV) injection of 2-AG (2-Arachidonoylglycerol, selective CB1 receptors agonist, 2µg) significantly increased food intake and this effect of 2-AG was attenuated by Picrotoxin (GABAA antagonist, 0.5µg) (P 0.001); but 21ng CGP54626 (GABAB antagonist) had no effect (p>0.05). Also, hyperphagic effect of CB65 (CB2 receptors agonist, 1.25µg) was not affected by Picrotoxin or CGP54626 (p>0.05). Moreover, the food intake of chicks was significantly increased by ICV injection of GABAA agonist (Gaboxadol, 0.2 µg) and SR141716A (CB1 receptors antagonist, 6.25µg) significantly decreased Gaboxadol-induced hyperphagia (P 0.001) but CB2 receptors antagonist (AM630, 1.25µg) had no effect. In contrast, co-injection of SR141716A or AM630 with GABAB agonist (baclofen, 0.2µg) had no effect on the hyperphagia induced by baclofen (p>0.05). These data showed there might be an interaction between central cannabinoidergic and GABAergic systems via CB1 and GABAA receptors in control of food intake in neonatal layer chicks.(AU)

Involvement of Gaba and Cannabinoid Receptors in Central Food Intake Regulation in Neonatal Layer Chicks: Role of CB1 and Gabaa Receptors

Feeding behavior is regulated via a complex network which interacts via diverse signals from central and peripheral tissues. Endocannabinoids modulate release of GABA in a variety of regions of the central nervous system. Endocannabinoids and GABAergic system have an important role in the central regulation of appetite. Thus, the present study examines the possible interaction of central canabinoidergic and GABAergic systems on food intake in 3-h food-deprived (FD3) neonatal layer-type chicks. The results of this study showed that intracerebroventricular (ICV) injection of 2-AG (2-Arachidonoylglycerol, selective CB1 receptors agonist, 2µg) significantly increased food intake and this effect of 2-AG was attenuated by Picrotoxin (GABAA antagonist, 0.5µg) (P 0.001); but 21ng CGP54626 (GABAB antagonist) had no effect (p>0.05). Also, hyperphagic effect of CB65 (CB2 receptors agonist, 1.25µg) was not affected by Picrotoxin or CGP54626 (p>0.05). Moreover, the food intake of chicks was significantly increased by ICV injection of GABAA agonist (Gaboxadol, 0.2 µg) and SR141716A (CB1 receptors antagonist, 6.25µg) significantly decreased Gaboxadol-induced hyperphagia (P 0.001) but CB2 receptors antagonist (AM630, 1.25µg) had no effect. In contrast, co-injection of SR141716A or AM630 with GABAB agonist (baclofen, 0.2µg) had no effect on the hyperphagia induced by baclofen (p>0.05). These data showed there might be an interaction between central cannabinoidergic and GABAergic systems via CB1 and GABAA receptors in control of food intake in neonatal layer chicks.

Utilização de gabapentina para manejo clínico de dor neuropática em cães - Relato de caso / Gabapentine for clinical management of neuropathic pain in dogs ­ Case report / Utilización de gabapentina para manejo clínico de dolor neuropático en perros ­ Relato de caso

Este artigo revisa a literatura sobre o uso da gabapentina e relata seu uso para tratamento e manejo clínico de um caso, dor neuropática em uma cadela da raça Schnauzer miniatura com idade de nove anos e massa corporal de 8,0 kg. Havia histórico de dor e claudicação, inicialmente nos membros torácicos e a seguir nos membros pélvicos. Após exame físico, exame neurológico e exames de laboratório e imagem, não se observou qualquer sinal de alteração óssea ou articular, sendo descartada a possibilidade de artrite e/ou artrose. Como o problema continuava a evoluir, a suspeita foi centrada na possibilidade de dor neuropática, definida como dor crônica causada por uma consequência direta de lesão ou disfunção dos axônios ou corpos dos neurônios, capaz de causar interrupção da bainha de mielina tanto em sistema nervoso periférico quanto central. Diagnosticar a dor em animais, que não possuem intelecto e são incapazes de falar, não é uma tarefa fácil, e na dor neuropática o problema é ainda maior. É difícil identificar quando os animais sentem sensações como formigamento, queimação e agulhamento, comuns na dor neuropática. Boa anamnese pode fornecer informações importantes para diagnosticar se um paciente está ou não vivenciando dor neuropática, e assim indicar tratamento específico. A dor neuropática costuma responder de forma insuficiente aos analgésicos comuns, sendo alguns fármacos anticonvulsivantes os principais agentes terapêuticos viáveis para esse tipo de dor, seja de origem central ou periférica. A gabapentina, anticonvulsivante de segunda geração, é uma substância análoga ao ácido ɤ-aminobutírico (GABA) com uma boa penetração na barreira hematoencefálica. É um dos novos fármacos antiepiléticos utilizados em pessoas, e só recentemente passou a ser empregada em cães, sendo atualmente utilizada com sucesso como adjuvante no tratamento de processos dolorosos crônicos e neuropáticos. No caso apresentado, o uso clínico da gabapentina foi eficaz no controle da dor neuropática, com importante redução dos sinais de dor e notória melhoria na qualidade de vida da paciente. Trata-se de uma opção terapêutica de custo baixo e fácil utilização, com baixo índice de efeitos adversos.(AU)

This paper reviews the literature on gabapentin and reports its use for treatment and clinical management in a case of neuropathic pain diagnosed in a nine-year-old miniature Schnauzer weighing 8.0 kg. The chief complaint concerned the history of pain and lameness, initially in the forelimbs and thereafter in the hind limbs. After physical examination, neurological examination, laboratory tests and image screening, no signals of bone or joint changes were observed, thus discarding the possibility of arthritis and/or osteoarthritis. Since the morbid condition continued to evolve, the clinical suspicion was focused on the possibility of neuropathic pain, defined as chronic pain caused by a direct consequence of injury or dysfunction of axons or bodies of neurons, causing disruption of the myelin sheath on both the peripheral and central nervous system. The diagnostic of pain in animals that lack intellect and are unable to speak is not an easy task, and with neuropathic pain the problem is even greater. It is difficult to identify when animals feel sensations such as tingling, burning and needling, common in neuropathic pain. Good history can provide important information to diagnose whether a patient is or is not experiencing neuropathic pain, and thus indicate specific treatments. Neuropathic pain tends to respond inadequately to common analgesics, with some anticonvulsant drugs being the main viable therapeutic agents for that kind of pain, whether of central or peripheral origin. Gabapentin, a second-generation antiepileptic substance, is analogous to ɤ-aminobutyric acid (GABA), with good penetration in the blood-brain barrier. It is one of the new antiepileptic drugs used in humans, and it has only recently started to be employed in dogs, being currently successfully used as an adjunct in the treatment of chronic and neuropathic pain processes. In this particular case, the clinical use of gabapentin was effective in controlling neuropathic pain, with significant reduction of pain signals and marked improvement in the quality of life of the patient. It is a relatively low-cost treatment option and easy to be used by pet owners, with a low rate of adverse effects.(AU)

Este artículo revisa la literatura sobre el uso de gabapentina y relata su uso para tratamiento y manejo clínico de un caso de dolor neuropático en una perra de la raza Schnauzer miniatura con edad de nueve años y masa corporal de 8,0 kg. Había histórico de dolor y claudicación, inicialmente los miembros torácicos y a seguir los miembros pélvicos. Tras examen físico, examen neurológico y exámenes de laboratorio e imagen, no se observó cualquier señal de alteración ósea o articular, siendo descartada la posibilidad de artritis o artrosis. Como el problema continuaba a evolucionar, la sospecha se centró en la posibilidad de dolor neuropático, definida como dolor crónica causada por una consecuencia directa de lesión o disfunción de los axones o cuerpos de las neuronas, capaz de causar interrupción de la vaina de mielina, tanto en el sistema nervioso periférico como central. Diagnosticar el dolor en animales, que no poseen intelecto y son incapaces de hablar no es una tarea fácil, y en el dolor neuropático aún es peor. Es difícil identificar cuando los animales sienten sensaciones como hormigueo, quemazón y agujetas, comunes en el dolor neuropático. Una buena anamnesis puede proporcionar importantes informaciones para diagnosticar si un paciente está o no vivenciando dolor neuropático, y así indicar tratamiento específico. El dolor neuropático puede responder de forma insuficiente a los analgésicos comunes, siendo algunos fármacos anticonvulsivantes los principales agentes terapéuticos viables para ese tipo de dolor, sea de origen central o periférico. La gabapentina, anticonvulsivante de segunda generación, es una sustancia análoga al ácido ɤ-aminobutírico (GABA) con buena penetración en la barrera hematoencefálica. Es uno de los nuevos fármacos antiepilépticos utilizados en personas, y solo recientemente pasó a ser empleada en perros, siendo actualmente utilizada con suceso como adyuvante en el tratamiento de procesos dolorosos crónicos y neuropáticos. En el caso presentado, el uso clínico de la gabapentina fue eficaz en el control del dolor neuropático, con importante reducción de los señales de dolor y notoria mejora en la calidad de vida del paciente. Se trata de una opción terapéutica de bajo costo y de fácil utilización, con bajo índice de efectos adversos.(AU)

Impact of dexmedetomidine on amino acid contents and the cerebral ultrastructure of rats with cerebral ischemia-reperfusion injury

Purpose: To investigate the effects of dexmedetomidine (DEX) on amino acid contents and the cerebral ultrastructure of rats with cerebral ischemia-reperfusion injury (I/R). Methods: Thirty-six, male, Wistar rats were randomly divided into three groups: the sham operation group (group C), the ischemia-reperfusion group (group I/R), and the DEX group (group D). The middle cerebral artery occlusion model was prepared by the modified Longa method. The time of ischemia was 180 min, and 120 min after reperfusion, the amount of glutamate (Glu), and -aminobutyric acid (GABA) in the brain were measured, and the ultrastructure-level changes in the cerebral cortex were examined using electron microscopy. Results: Compared to group C, Glu contents in group D, and I/R significantly increased. Compared to group I/R, Glu contents in group D significantly decreased. Compared to group C, GABA contents in group D, and I/R significantly increased, and those in group D significantly increased, as compared to group I/R. The cerebral ultrastructure was normal in group C. Vacuolar degeneration in the plastiosome and nervous processes, was more critical than in group D. Vascular endothelial cells (VEC) were damaged. On the contrary, these changes in group D significantly improved. Conclusion: Dexmedetomidine is capable of decreasing glutamergic content, and increasing GABAergic content, in order to decrease the injury of the cerebral ultrastructure, following cerebral ischemia-reperfusion injury.(AU)

Utilização de gabapentina para manejo clínico de dor neuropática em cães - Relato de caso / Gabapentine for clinical management of neuropathic pain in dogs ­ Case report / Utilización de gabapentina para manejo clínico de dolor neuropático en perros ­ Relato de caso

Este artigo revisa a literatura sobre o uso da gabapentina e relata seu uso para tratamento e manejo clínico de um caso, dor neuropática em uma cadela da raça Schnauzer miniatura com idade de nove anos e massa corporal de 8,0 kg. Havia histórico de dor e claudicação, inicialmente nos membros torácicos e a seguir nos membros pélvicos. Após exame físico, exame neurológico e exames de laboratório e imagem, não se observou qualquer sinal de alteração óssea ou articular, sendo descartada a possibilidade de artrite e/ou artrose. Como o problema continuava a evoluir, a suspeita foi centrada na possibilidade de dor neuropática, definida como dor crônica causada por uma consequência direta de lesão ou disfunção dos axônios ou corpos dos neurônios, capaz de causar interrupção da bainha de mielina tanto em sistema nervoso periférico quanto central. Diagnosticar a dor em animais, que não possuem intelecto e são incapazes de falar, não é uma tarefa fácil, e na dor neuropática o problema é ainda maior. É difícil identificar quando os animais sentem sensações como formigamento, queimação e agulhamento, comuns na dor neuropática. Boa anamnese pode fornecer informações importantes para diagnosticar se um paciente está ou não vivenciando dor neuropática, e assim indicar tratamento específico. A dor neuropática costuma responder de forma insuficiente aos analgésicos comuns, sendo alguns fármacos anticonvulsivantes os principais agentes terapêuticos viáveis para esse tipo de dor, seja de origem central ou periférica. (AU)

This paper reviews the literature on gabapentin and reports its use for treatment and clinical management in a case of neuropathic pain diagnosed in a nine-year-old miniature Schnauzer weighing 8.0 kg. The chief complaint concerned the history of pain and lameness, initially in the forelimbs and thereafter in the hind limbs. After physical examination, neurological examination, laboratory tests and image screening, no signals of bone or joint changes were observed, thus discarding the possibility of arthritis and/or osteoarthritis. Since the morbid condition continued to evolve, the clinical suspicion was focused on the possibility of neuropathic pain, defined as chronic pain caused by a direct consequence of injury or dysfunction of axons or bodies of neurons, causing disruption of the myelin sheath on both the peripheral and central nervous system. The diagnostic of pain in animals that lack intellect and are unable to speak is not an easy task, and with neuropathic pain the problem is even greater. It is difficult to identify when animals feel sensations such as tingling, burning and needling, common in neuropathic pain. Good history can provide important information to diagnose whether a patient is or is not experiencing neuropathic pain, and thus indicate specific treatments. Neuropathic pain tends to respond inadequately to common analgesics, with some anticonvulsant drugs being the main viable therapeutic agents for that kind of pain, whether of central or peripheral origin. Gabapentin, a second-generation antiepileptic substance, is analogous to ɤ-aminobutyric acid (GABA), with good penetration in the blood-brain barrier. It is one of the new antiepileptic drugs used in humans, and it has only recently started to be employed in dogs, being currently successfully used as an adjunct in the treatment of chronic and neuropathic pain processes(AU)

Este artículo revisa la literatura sobre el uso de gabapentina y relata su uso para tratamiento y manejo clínico de un caso de dolor neuropático en una perra de la raza Schnauzer miniatura con edad de nueve años y masa corporal de 8,0 kg. Había histórico de dolor y claudicación, inicialmente los miembros torácicos y a seguir los miembros pélvicos. Tras examen físico, examen neurológico y exámenes de laboratorio e imagen, no se observó cualquier señal de alteración ósea o articular, siendo descartada la posibilidad de artritis o artrosis. Como el problema continuaba a evolucionar, la sospecha se centró en la posibilidad de dolor neuropático, definida como dolor crónica causada por una consecuencia directa de lesión o disfunción de los axones o cuerpos de las neuronas, capaz de causar interrupción de la vaina de mielina, tanto en el sistema nervioso periférico como central. Diagnosticar el dolor en animales, que no poseen intelecto y son incapaces de hablar no es una tarea fácil, y en el dolor neuropático aún es peor. Es difícil identificar cuando los animales sienten sensaciones como hormigueo, quemazón y agujetas, comunes en el dolor neuropático. Una buena anamnesis puede proporcionar importantes informaciones para diagnosticar si un paciente está o no vivenciando dolor neuropático, y así indicar tratamiento específico. El dolor neuropático puede responder de forma insuficiente a los analgésicos comunes, siendo algunos fármacos anticonvulsivantes los principales agentes terapéuticos viables para ese tipo de dolor, sea de origen central o periférico. La gabapentina, anticonvulsivante de segunda generación, es una sustancia análoga al ácido ɤ-aminobutírico (GABA) con buena penetración en la barrera hematoencefálica.(AU)