Efecto de Petiveria alliacea y drogas colinérgicas sobre la habituación / Effects of Petiveria alliacea and cholinergic drugs on the habituation cognitive behavior

Petiveria alliacea (PA) have anxiolytic, antidepressant and cognitive effects. In the present paper the effect of PA water infusion and cholinergic drugs on cognitive behavior were studied. For that, 40 male NMRI mice were divided in 4 groups: Control (n=10), Drug Control (n=10), PA (n=10) and PA plus Drug (n=10). PA 1% was administered orally (7.59±1.39 ml/day); while scopolamine (2 mg/Kg), galantamine (1 mg/Kg) and nicotine (0.1 mg/Kg) were administered intraperitoneally. Behavioral tests included: anxiety maze (AM), open field (OF) and marble burying (MB). Habituation cognitive behavior was evaluated in 4 sessions, one week each session. PA had anxiolytic and antidepressant effect effect in AM, combined with nicotine potentiated an anxiogenic effect in AM, galantamine favored habituation in OF. Scopolamine potentiated the habituation in LA and decreased the obsessive-compulsive behavior in OF. In conclusion; PA had an anxiolytic effect and favored deshabituation, combined with nicotine induced an anxiogenic effect, galantamine favored habituation and scopolamine decreased obsessive-compulsive behavior and favored motor habituation indicated a possible anxiolytic effect.

La Petiveria alliacea (PA) está relacionada con efectos ansiolíticos, antidepresivos y cognitivos. El presente trabajo estudió el efecto de la infusión de PA y drogas colinérgicas sobre la habituación. 40 ratones NMRI machos fueron divididos en 4 grupos: Control (n=10), Control Drogas (n=10), PA (n=10) y PA plus Drogas (n=10). La PA (1%) fue administrada vía oral (7.59±1.39 ml/día); escopolamina (2 mg/Kg), galantamina (1 mg/Kg) y nicotina (0.1 mg/Kg) fueron administrados vía intraperitoneal. Los ensayos conductuales incluyeron: laberinto de ansiedad (LA), campo abierto (CA) y enterramiento aversivo (EA). La habituación fue evaluada en 4 sesiones con duración de una semana cada una. PA mostró un efecto ansiolítico en el LA, combinada con nicotina potenció un efecto ansiogénico en el LA. Galantamina favoreció la habituación en CA, y escopolamina potenció el fenómeno de habituación en LA y disminuyó la conducta obsesivo-compulsiva en CA. En conclusión, la PA mostró un efecto ansiolítico y antidepresivo que potencia la deshabituación, combinada con nicotina indujo un efecto ansiogénico, galantamina favoreció la habituación y escopolamina disminuyó la conducta obsesivo­ compulsiva y favoreció la habituación motora indicando un posible efecto ansiolítico.

La capacidad de los neonatos de regular sus estados de conciencia y la habituación ¿marcadores tempranos de dificultades en el desarrollo? / Neonatal capacity of regulation of behavioral states and habituation ¿Early markers of neurodevelopment impairment?

Desde la etapa neonatal, la detección temprana de marcadores conductuales de alteraciones sutiles en el neurodesarrollo, es un campo todavía en crecimiento. El objetivo de esta revisión es describir los mecanismos que subyacen a la conducta del neonato durante la aplicación de la subescala de habituación que forma parte de la Neonatal Behavioral Assessment Scale (NBAS), con especial énfasis en la vía visual. Se destacan el papel de la habituación y la regulación de los estados de conciencia como los mecanismos fundamentales durante el primer estímulo y del segundo al décimo estímulo, en dicha escala. Estos procesos representan una capacidad fundamental para la adaptación del recién nacido y se discuten sus posibles implicaciones en el desempeño cognitivo posterior.

Since the neonatal stage, early detection of behavioral markers of subtle impairments in neurodevelopment is a field still under growth. The objective of this review is to describe the mechanisms underlying neonatal behavior during the habituation scale of NBAS, that emphasizes the visual pathway. The role of habituation and the regulation of behavioral states are highlighted during the first stimuli and the second to ten stimuli, during performance of NBAS. Those processes represent a fundamental capacity for newborns´ adaptation and are discussed in line to later cognitive performance.

Percepción del gusto como factor de riesgo para obesidad infantil / Taste perception as a risk factor for childhood obesity

Resumen Objetivo Describir el papel de la percepción del gusto como factor de riesgo para el desarrollo de obesidad en niños. Material y métodos Se realizó una búsqueda inicial de artículos científicos publicados en PubMed entre el 1 de enero de 2011 y el 20 de marzo de 2016 para el tema sobrepeso y obesidad en niños de entre 0 y 12 años. Los algoritmos utilizados fueron (Obesity OR Overweight) AND Taste perception, Satiation, Satiety response, Appetite, Appetite regulation, Habituation, Taste receptors [MeSH] y PROP phenotype. En búsquedas subsecuentes se incluyeron artículos previos y posteriores a la fecha de la búsqueda general (hasta mayo 2018). Resultados Las preferencias por los sabores inician desde la gestación, por lo que los niños que son expuestos a sabores dulces en etapas tempranas de la infancia aumentan su riesgo de habituación a éstos. Asimismo, las experiencias hedónicas dadas por la ingestión de alimentos y bebidas dulces refuerzan el consumo de estos alimentos, lo que propicia la selección de productos o bebidas de sabor dulce en etapas posteriores. Estas preferencias se han asociado con el desarrollo de obesidad en los niños. Las variantes genéticas relacionadas con la percepción del gusto también pueden contribuir a la selección de cierto tipo de alimentos. Sin embargo, su relación con una mayor ingestión de energía, así como con un mayor peso corporal, ha sido poco explorada y ha mostrado resultados inconsistentes. Conclusiones Se requiere más evidencia para entender las interacciones ambientales y genéticas de la percepción del gusto, a fin de considerarlo un factor más en las intervenciones de política pública.

Abstract Objective To describe the role of taste perception in the development of sweet taste habituation as well as its relationship to the development of obesity in children. Materials and methods An initial search of scientific articles published in PubMed between January 1st, 2011 and March 20th, 2016 was performed in children between 0 and 12 years old. The algorithms used were (Obesity OR Overweight) AND (Taste perception, Satiation, Satiety response, Appetite, Appetite regulation Habituation, Taste receptors [MeSH]) and PROP phenotype. Subsequent searches included papers published before and after date of initial search (until May 2018). Results Flavor preferences start as early as taste system development during pregnancy. Therefore, children who are exposed to sweet flavors in early childhood, increase their risk of habituation to them. Likewise, the hedonic experiences given by the ingestion of sweet foods and beverages, reinforce the consumption of these foods, perpetuating their selection in later stages. Preference for sweet taste has been associated with the development of obesity in children. Functional genetic variants related to taste perception can also contribute to the selection of certain types of foods and there is enough evidence that supports this idea. However, its contribution to a higher energy intake as well as a higher body weight has been poorly explored with inconsistent results. Conclusions More evidence is required to understand the environmental and genetic interactions of taste perception, so in turn, it can be consider as a key factor for preventing child obesity.

Social instigation and repeated aggressive confrontations in male Swiss mice: analysis of plasma corticosterone, CRF and BDNF levels in limbic brain areas / Instigação social e confrontos agressivos repetidos em camundongos Swiss machos: análise de corticosterona plasmática e dos níveis de CRF e BDNF em áreas cerebrais límbicas

Abstract Introduction: Agonistic behaviors help to ensure survival, provide advantage in competition, and communicate social status. The resident-intruder paradigm, an animal model based on male intraspecific confrontations, can be an ethologically relevant tool to investigate the neurobiology of aggressive behavior. Objectives: To examine behavioral and neurobiological mechanisms of aggressive behavior in male Swiss mice exposed to repeated confrontations in the resident intruder paradigm. Methods: Behavioral analysis was performed in association with measurements of plasma corticosterone of mice repeatedly exposed to a potential rival nearby, but inaccessible (social instigation), or to 10 sessions of social instigation followed by direct aggressive encounters. Moreover, corticotropin-releasing factor (CRF) and brain-derived neurotrophic factor (BNDF) were measured in the brain of these animals. Control mice were exposed to neither social instigation nor aggressive confrontations. Results: Mice exposed to aggressive confrontations exhibited a similar pattern of species-typical aggressive and non-aggressive behaviors on the first and the last session. Moreover, in contrast to social instigation only, repeated aggressive confrontations promoted an increase in plasma corticosterone. After 10 aggressive confrontation sessions, mice presented a non-significant trend toward reducing hippocampal levels of CRF, which inversely correlated with plasma corticosterone levels. Conversely, repeated sessions of social instigation or aggressive confrontation did not alter BDNF concentrations at the prefrontal cortex and hippocampus. Conclusion: Exposure to repeated episodes of aggressive encounters did not promote habituation over time. Additionally, CRF seems to be involved in physiological responses to social stressors.

Resumo Introdução: Comportamentos agonísticos ajudam a garantir a sobrevivência, oferecem vantagem na competição e comunicam status social. O paradigma residente-intruso, modelo animal baseado em confrontos intraespecíficos entre machos, pode ser uma ferramenta etológica relevante para investigar a neurobiologia do comportamento agressivo. Objetivos: Analisar os mecanismos comportamentais e neurobiológicos do comportamento agressivo em camundongos Swiss machos expostos a confrontos repetidos no paradigma residente-intruso. Métodos: A análise comportamental foi realizada em associação com medidas de corticosterona plasmática em camundongos expostos repetidamente a um rival em potencial próximo, porém inacessível (instigação social), ou a 10 sessões de instigação social seguidas de encontros agressivos diretos. Além disso, o fator de liberação de corticotrofina (CRF) e o fator neurotrófico derivado do cérebro (BNDF) foram medidos no encéfalo desses animais. Camundongos controles não foram expostos à instigação social ou confrontos agressivos. Resultados: Os camundongos expostos a confrontos agressivos exibiram um padrão semelhante de comportamentos agressivos e não agressivos típicos da espécie na primeira e na última sessão. Em contraste com instigação social apenas, confrontos agressivos repetidos promoveram aumento na corticosterona plasmática. Após 10 sessões de confrontos agressivos, os camundongos apresentaram uma tendência não significativa de redução dos níveis de CRF no hipocampo, que se correlacionaram inversamente com os níveis plasmáticos de corticosterona. Por outro lado, sessões repetidas de instigação social ou confronto agressivo não alteraram as concentrações de BDNF no córtex pré-frontal e hipocampo. Conclusão: A exposição a episódios repetidos de encontros agressivos não promoveu habituação ao longo do tempo. Adicionalmente, o CRF parece estar envolvido nas respostas fisiológicas aos estressores sociais.

De la otredad a la praxis liberadora: la construcción de métodos para la conciencia / From otherness to liberating praxis: the construction of methods for consciousness

En esta conferencia se presentan las bases analécticas de las formas de producir en la praxis cambios conducentes a la concientización: esto es, a la transformación de la conciencia en cuanto a formas consideradas como modos únicos y cotidianos de producir la vida social. En tal sentido, se definen y analizan cuatro modos que son parte de la vida cotidiana: la habituación y la naturalización, así como la ideologización y la alienación, cuyas bases se afirman en los primeros modos citados. Asimismo se presentan las características del método analéctico construidas en la praxis, indicando la posibilidad de aplicar la acción a otros modos de interpretar la vida cotidiana, igualmente alienadores.

In this conference, we present the analectical methods of the ways to produce, in praxis, forceful changes to consciousness: that is to say, the transformation of the conscious in regards to, for example, the unique and everyday manners of producing social situations. In this sense, four ways, each part of everyday life, are defined and analysed: habituation and naturalization, as well as ideologization and alienation, whose basis is affirmed in the first ways mentioned above. At the same time, the characteristics of the analectical method are presented, built in praxis, indicating the possibility of applying the actions to other ways of interpreting everyday life, which are equally alienating.

Problemas bioéticos en la investigación de nuevas vacunas: ¿obedecen a razones de salud pública? / Bioethical problems in researching new vaccines: Do they respond to public health reasons?

Los problemas éticos de las investigaciones sobre vacunas han crecido en las últimas décadas en frecuencia y magnitud debido a la posición dominante de la industria farmacéutica en el desarrollo de esos estudios. Las tradicionales cuestiones de seguridad y eficacia se han visto agravadas por el conflicto de intereses introducido por la competencia comercial en un mercado a escala global de miles de millones de dólares. La integridad profesional de los investigadores, la responsabilidad moral de los patrocinadores, y la regulación y control por parte de los Estados nacionales, se muestra cuestionada en varios ejemplos. Los resultados de estos cambios son las amenazas a la protección de los derechos de las personas incluidas en estas investigaciones y el discutible progreso que resulta para la salud pública.

The ethical problems in vaccine research have grown in frequency and magnitude in last decades, due to the dominant place of the pharmaceutical industry in the development of such studies. Traditional issues of security and efficacy have been aggravated by the conflicts of interests introduced by commercial competition in a global market worth billions of dollars. We present here a few examples in which the professional integrity of researchers, the moral responsibility of sponsors, and the public regulation and control by national States are put into question. The consequences of these changes represent serious threats to the rights of people included in these studies as well as disputable progress for public health.

Habituation of the blink reflex in the neonatal period and development of auditory processing / Habituação do reflexo cócleo-palpebral no período neonatal e desenvolvimento auditivo

Objective: To verify the existence of an association between the presence/absence of the blink reflex habituation in the neonatal period as well as the auditory processing development. Methods: The occurrence of blink reflex habituation was studied in 33 neurologically normal neonates, who had their behavioral responses analyzed and classified according to Azevedo (1993), between 9 and 25 months of age. Habituation of the blink reflex was verified using a sound stimulus of nearly 90 dB. The stage of the auditory processing development was evaluated through a sound stimulus of nearly 41 dB. Statistical data were analyzed with Fischer and X2 tests. Results: Out of the 33 studied children, 22 presented blink reflex habituation in the first stage of the study. In 7 of them, the auditory processing stage matched their chronological age, while in 15 of them, the auditory processing stage was found inadequate to their chronological age. Eleven children failed to present habituation of the blink reflex in the first stage of the study. From this group, eight children disclosed auditory responses that were adequate to their chronological age and three, inadequate. A statistically significant association between the presence of blink reflex habituation and an auditory processing delay was verified as well as between the absence of the blink reflex habituation and chronologically suitable responses. Conclusions: The presence of blink reflex habituation in the neonatal period does not seem to be a predictive factor of the adequate auditory processing.

Objetivo: Verificar a existência de associação entre presença/ausência de habituação do reflexo cócleo-palpebral no período neonatal bem como o desenvolvimento do processamento auditivo. Métodos: Pesquisou-se a ocorrência de habituação do reflexo cócleo-palpebral em 33 neonatos neurologicamente normais, os quais, entre 9 e 25 meses de idade, tiveram suas respostas comportamentais avaliadas e classificadas segundo Azevedo (1993). A habituação do reflexo cócleo-palpebral foi verificada utilizando-se estímulo sonoro de aproximadamente 90 dB. A etapa do desenvolvimento do processamento auditivo foi avaliada com estímulo sonoro aproximado de 41 dB. A análise estatística dos dados foi realizada por meio dos testes Fischer e X2. Resultados: Das 33 crianças estudadas, 22 evidenciaram habituação do reflexo cócleo-palpebral na primeira etapa do estudo. A etapa do processamento auditivo de 7 delas foi considerada adequada à idade cronológica e de 15 inadequada. Onze crianças não evidenciaram habituação do reflexo cócleo-palpebral na primeira etapa do estudo. Desse grupo, oito crianças manifestaram respostas auditivas adequadas para a idade cronológica e três inadequadas. Verificou-se associação estatisticamente significante entre presença de habituação do reflexo cócleo-palpebral e atraso nas etapas do processamento auditivo, e também entre ausência de habituação do reflexo cócleo-palpebral e respostas adequadas à idade cronológica. Conclusões: A presença de habituação do reflexo cócleo-palpebral no período neonatal parece não ser fator preditivo do adequado desenvolvimento do processamento auditivo.

Habituation of the eyeblink response in humans with stimuli presented in a sequence of incremental intensity

In an experiment we examined whether the repeated presentation of tones of gradually increasing intensities produces greater decrement in the eyeblink reflex response in humans than the repetition of tones of constant intensities. Two groups of participants matched for their initial level of response were exposed to 110 tones of 100-ms duration. For the participants in the incremental group, the tones increased from 60- to 90- dB in 3-dB steps, whereas participants in the constant group received the tones at a fixed 90-dB intensity. The results indicated that the level of response in the last block of 10 trials, in which both groups received 90-dB tones, was significantly lower in the incremental group than in the constant group. These findings support the data presented by Davis and Wagner (7) with the acoustic response in rats, but differ from several reports with autonomic responses in humans, where the advantage of the incremental condition has not been observed unambiguously. The discussion analyzes theoretical approaches to this phenomenon and the possible involvement of separate neural circuits.

Respuestas psicofisiológicas y cognitivas ante situaciones estresantes en estudiantes de la Universidad Simón Bolívar / Psychophysiological and cognitive responses to stressful situations in students of the Universidad Simón Bolívar

En esta investigación se midió la respuesta cardiovascular al estrés, autoeficacia computacional y la percepción de dificultad de la tarea, en una muestra de 115 estudiantes de pregrado de la Universidad Simón Bolívar. Los resultados evidencian que en cuanto a los parámetros fisiológicos cardiovasculares, hubo elevación en la presión arterial y la frecuencia cardíaca en ambas versiones del test de stroop (clásico y computarizado). En general, la percepción de la dificultad de la tarea en estos sujetos fue más elevada ante el stroop clásico. Finalmente, en relación con la autoeficacia computacional los sujetos presentan valores altos, lo cual indica una percepción de habilidades para trabajar frente a un computador. Estos resultados representan una contribución importante, pues están indicando la relación de las variables cognitivas y las respuestas fisiológicas del estudiante universitario ante situaciones demandantes o difíciles. De esta manera, las situaciones vividas en el ambiente académico pueden tener un impacto relevante en los estados de salud, y debemos tomar en consideración estos aspectos para el beneficio integral del estudiante

In this investigation of the Cardiovascular Response to Stress, Perceived Task Difficulty and physiological responding were measured. The study used a sample of 115 undergraduate students of a Simon Bolivar University. Results show that a great elevation of heart rate and blood pressure was observed during exposure to the two versions of the Stroop Test (classical and computerized). In general, ratings of perceived difficulty of the Stroop task were higher in response to the Classical administration. Finally, subjects rated their Computer Self-Efficacy as high, indicating confidence and comfort working with computers. These results represent an important contribution that illustrate the relation of cognitive factors to physiological responses during cognitively demanding or difficult situations. In terms of the practical implications of these findings, situations experienced in academic environments can have a prominent impact in cardiovascular responding, and thus, health. As such, it is indicating that the medium of academic assessment might be an appropriate target for change in some settings for the benefit of the Student

Aprendizagem vicária de treino de toalete através de filme de animação: estudo de caso em ludoterapia comportamental / Vicarious learning in toilet training through an animated film: Case study of behavioral play therapy

Este trabalho consiste no relato do atendimento, em ludoterapia comportamental, de Lara (4 anos e 5 meses), que apresentava encoprese secundária retentiva, o que acarretava um intervalo entre as defecações superior a 72 horas. Método: a avaliação consistiu em entrevista com pais e babás, observação na escola, sessões lúdicas e sessões lúdicas familiares; as intervenções enfatizaram o uso de filme de animação, atividades lúdicas e brinquedos para obter a habituação comportamental e realizar o treino do toalete. Resultado: após a intervenção, utilizando filme de animação, Lara defecou no consultório, manteve o comportamento diário de defecação durante 18 meses de acompanhamento e apresentou três acidentes críticos nesse período. Discussão: o filme de animação é sugerido como a principal intervenção para a mudança de comportamento de Lara. Provavelmente, após observar os personagens do filme de animação realizando o treino de toalete e obterem adesivos, Lara foi reforçada vicariamente e aprendeu a relação entre o comportamento dos personagens (treino do toalete) e a conseqüência obtida por eles (adesivo). A brincadeira com as bonecas utilizadas no filme é concebida como um tipo de mediação lúdica.

This paper is a report of the treatment of Lara (4 years and 5 months old) who was experiencing secondary retentive encopresis, with an interval of over 72 hours between defecations. Methods: the evaluation was conducted through interviews with the parents and the nannies, observation at school, individual play sessions and family play sessions; the interventions focused on the use of animated films, play activities and toys to develop behavioral habits and toilet training. Results: after the intervention with the animated film, Lara defecated in the office and had daily defecations during the next 18 months of treatment; she had three serious accidents in this period. Discussion: most likely, after watching the characters’ toilet training and the stickers they got in the animated film, Lara was vicariously reinforced and learned the relationship between the behavior of the characters (toilet training) and the consequent reward (sticker). The game with the dolls used in the film is considered a type of play mediation.

Habituation of exploratory activity in aged rats: effects of pyritinol

A acetilcolina é um neurotransmissor que desempenha considerável papel crítico nos processos subjacentes ao comportamento, aprendizagem e memória. Piritinol (piritioxina, Encefabolâ, PRT) é um fármaco nootrópico que aumenta a transmissão colinérgica no sistema nervoso central. Habituação comportamental seguida de múltipla exposição no campo aberto é um paradigma experimental freqüentemente usado na avaliação das ações cognitivas de fármacos. Neste paradigma, a diminuição da atividade exploratória em função da exposição repetida ao mesmo ambiente é considerada como índice de memória. No presente estudo, os efeitos do piritinol (PRT) na forma de pó adicionado a dieta (200 mg/kg/dia, p.o., durante 14 dias) sobre a habituação em ratos idosos foram avaliados no campo aberto. Um total de 18 ratos idosos foram randomizados e divididos em dois grupos: controle (tratado com veículo, n=8) e experimental (tratado com PRT, n=10). Na avaliação da tarefa exploratória, o tratamento com PRT diminuiu significantemente os números totais de área cruzada e do levantar quando comparados com o grupo controle, indicando habituação. O tratamento com PRT aumentou a retenção no número total de cruzamentos e levantar quando comparado com o grupo controle. A análise dos dados em conjunto, sugere que o sistema muscarínico colinérgico pode estar envolvido com os efeitos da PRT sobre a habituação da atividade exploratória em ratos idosos.

Female novelty and the courtship behavior of male guinea pigs (Cavia porcellus)

In several rodent species, an increase or recovery of sexual behavior can be observed when sexually satiated males are placed in contact with a novel mate. In order to assess the influence of female novelty on the courtship behavior of guinea pigs (Cavia porcellus), four adult males were observed during four daily 15-min sessions while interacting with the same pregnant female (same-female sessions). A new female was presented during the fifth session (switched-female session). The duration of behavioral categories was obtained from videotape records using an observational software. From the first to the second session, all males decreased the time allocated to investigating (sniffing and licking), following, and mounting the female, and that response did not recover by the end of the same-female sessions. No similar decreasing tendencies were detected in the circling or rumba categories. A marked increase of investigating occurred in all males from the last same-female session (8.1, 11.9, 15.1 and 17.3 percent session time) to the switched-female one (16.4, 18.4, 37.1 and 28.9 percent session time, respectively). Increases in following and circling were recorded in three of four males, and full-blown recovery of mounting in one male. No consistent changes in the females' responses to males (following or attacking) were observed throughout testing. These results are consistent with the hypothesis that guinea pig males recognize individual females and that courtship responses may suffer a habituation/recovery process controlled by mate novelty.

Avaliação da inteligência na primeira infância / Intelligence assessment in early childhood

Tradicionalmente, a inteligência é avaliada por instrumentos psicométricos. Em se tratando da avaliação cognitiva na primeira infância (0 a 36 meses de idade), os testes geralmente baseiam-se em critérios de desempenho psicomotor. Meio século de pesquisas tem demonstrado pouca ou nenhuma associação entre o que é requisitado nas escalas clássicas de desenvolvimento infantil e a performance cognitiva nos anos posteriores. Tais resultados fortaleceram a crença na descontinuidade do desenvolvimento da inteligência ao longo do ciclo vital. No entanto, há recentes evidências de que medidas de processamento de informação podem trazer respostas ao desafio de encontrar maiores correlações entre as pontuações em inteligência nos primeiros anos de vida e posteriores do que as obtidas por meio dos testes de desenvolvimento psicomotor. Índices de habituação visual e preferência pela novidade, bastante livres de requisitos motores, têm apresentado moderada validade preditiva em relação ao desenvolvimento cognitivo. No presente trabalho apresentam-se os principais estudos a esse respeito

Pharmacological differences between memory consolidation of habituation to an open field and inhibitory avoidance learning

Rats implanted bilaterally with cannulae in the CA1 region of the dorsal hippocampus or the entorhinal cortex were submitted to either a one-trial inhibitory avoidance task, or to 5 min of habituation to an open field. Immediately after training, they received intrahippocampal or intraentorhinal 0.5-æl infusions of saline, of a vehicle (2 percent dimethylsulfoxide in saline), of the glutamatergic N-methyl-D-aspartate (NMDA) receptor antagonist 2-amino-5-phosphono pentanoic acid (AP5), of the protein kinase A inhibitor Rp-cAMPs (0.5 æg/side), of the calcium-calmodulin protein kinase II inhibitor KN-62, of the dopaminergic D1 antagonist SCH23390, or of the mitogen-activated protein kinase kinase inhibitor PD098059. Animals were tested in each task 24 h after training. Intrahippocampal KN-62 was amnestic for habituation; none of the other treatments had any effect on the retention of this task. In contrast, all of them strongly affected memory of the avoidance task. Intrahippocampal Rp-cAMPs, KN-62 and AP5, and intraentorhinal Rp-cAMPs, KN-62, PD098059 and SCH23390 caused retrograde amnesia. In view of the known actions of the treatments used, the present findings point to important biochemical differences in memory consolidation processes of the two tasks

Effects of oxytocin and an oxytocin receptor antagonist on retention of a nose-poke habituation response in mice

The present study describes the use of nose-poke habituation as a memory task in mice and demonstrates that it is sensitive to oxytocin (OT) and an oxytocin receptor antagonist (AOT) administered after the learning trial. Habituation of nose-poke behavior of mice was defined as a reduction in number of nose-pokes compared to baseline, and was measured in a hole-board apparatus to which male Swiss mice were exposed on two consecutive days for 5 min, respectively. Immediate post-training subcutaneous administration of OT (2.00 mug/kg) impaired retention performance, whereas AOT (0.20 mug/kg) enhanced it. Neither the impairing effects of OT (2.00 mug/kg) nor the enhancing effects of AOT (0.20 mug/kg) were seen when the training treatment interval was 180 min, suggesting that both treatments influenced the storage of recently acquired information. The effects of OT (2.00 mug/kg) on retention were prevented by AOT (0.02 mug/kg) administered immediately after training but 10 min prior OT treatment. This dose of antagonist did not affect retention by itself which suggest that impairing effects of OT on retention are probably due to an interaction of the neuropeptide with specific receptors. The actions of OT and AOT on retention were not due to enduring proactive effects of the compounds on performance during the retention test, since when given to untrained mice did not modify their spontaneous activities in the hole-board when recorded 24 h later. We suggest that nose-poke habituation learning can be a suitable method to investigate the mnestic effects of drugs, and that oxytocin negatively modulates memory storage of this form of learning elicited by stimuli repeatedly presented without reinforcement.

Long-term habituation (LTH) in the crab Chasmagnathus: a model for behavioral and mechanistic studies of memory

A decade of studies on long-term habituation (LTH) in the crab Chasmagnathus is reviewed. Upon sudden presentation of a passing object overhead, the crab reacts with an escape response that habituates promptly and for at least five days. LTH proved to be an instance of associative memory and showed context, stimulus frequency and circadian phase specificity. A strong training protocol (STP) (( 15 trials, intertrial interval (ITI) of 171 s) invariably yielded LTH, while a weak training protocol (WTP) (( 10 trials, ITI = 171 s) invariably failed. STP was used with a presumably amnestic agent and WTP with a presumably hypermnestic agent. Remarkably, systemic admministration of low doses was effective, which is likley to be due to the lack of an endothelial blood-brain barrier. LTH was blocked by inhibitors of protein and RNA synthesis, enhanced by protein kinase A (PKA) activators and reduced by PKA inhibitors, facilitated by angiotensin II and IV and disrupted by saralasin. The presence of angiotensins and related compounds in the crab brain was demonstrated. Diverse results suggest that LTH includes two components: an inital memory produced by spaced training and mainly expressed at an inital phase of testing, and a retraining memory produced by massed training and expressed at a later phase of testing (retraining). The inital memory would be associative, context specific and sensitive to cycloheximide, while the retraining memory would be nonassociative, context independent and insensitive to cycloheximide.

Temperamento y personalidad en deficientes mentales / Temperament and personality in mental deficients

Se revisan los estudos sobre el temperamento y la personalidad de los deficientes mentales, se discute la hipótesis del déficit de inhibición y se estudia la aplicación de las dimensiones temperamentales básicas de extraversión y neuroticismo. Se concluye que no puede hablarse de un temperamento propio de los deficientes, puesto que se encuentra tanta variabilidad en el temperamento de los deficientes mentales como entre la población general; y que la consideración conjunta del temperamento, por un lado, y de la historia personal y la situación actual, por otro, permite dar cuenta, como en la población general, de las deficiencias individuales en los rasgos de personalidad de los deficientes mentales.

Habituaçäo e sensibilizaçäo comportamental / Behavioral habituation and sensitization

Apresenta uma revisäo crítica das principais teorias de habituaçäo e sensibilizaçäo comportamental. Habituaçäo se refere ao desvanecimento da resposta ao longo de uma estimulaçäo monótona, e sensibilizaçäo se refere a processos de incremento da resposta. A aparente simplicidade desses fenômenos e sua vasta distribuiçäo na escala animal induziram pesquisadores a abrigarem sob um mesmo rótulo fenômenos bastante diferentes quanto à natureza e aos mecanismos causais envolvidos, gerando desacordos quanto a definiçöes comportamentais mais detalhadas. Empiricamente os detalhes desses processos de incremento e decréscimo de resposta säo bastante complexos porque os dois processos costumam ocorrer juntos. Os problemas encontrados no estudo desses processos säo particularmente agudos nos estudos de animais em situaçöes relativamente livres como no campo aberto ou na natureza, onde a occorrência de outros fenômenos ainda mais complexos torna a análise ainda mais complexa

Effect of withdrawal from long-term nifedipine administration on open-field habituation in the rat

The effects of withdrawal from long-term administration of nifedipine (2.5 mg/kg, ip, twice daily for 30 days) on open-field habituation were evaluated in 3-month old male Wistar rats (13-14 animals per group). Habituation was evaluated by the ratio between locomotion or rearing frequencies obtained in the second and the first open-field session for each animal. Nifedipine treatment did not modify the locomotion ratio (with a mean +/- SEM ratio of 0.66 +/- 0.12 for control and 0.45 +/- 0.08 for nifedipine-treated group) nor the rearing ratio (with a mean +/- SEM ratio of 0.51 +/- 0.12 for control and 0.62 +/- 0.18 for nifedipine-treated group). The possible factors underlying the discrepancy between the present results and the commonly reported positive effects of calcium channel blockers on memory are discussed.