Ketamine causes poor maternal care in rats with postpartum depression and leads to few behavioral and neurochemical alterations on male offspring.

Ketamine is an anesthetic drug that also has antidepressant properties, with quick action. Despite the great number of studies showing its effectiveness as a treatment for major depression, there is little information about its effects on postpartum depression, as pharmacological treatments bring risks to the health of both mother and child. Thus, this study aimed to evaluate the effects of prolonged treatment with subanesthetic doses of ketamine in a rat model of postpartum depression. Female dams were induced to postpartum depression by the maternal separation model from lactating day (LD) 2-12. They were divided into four groups: one control and three experimental groups, which were treated with different doses of ketamine (5, 10 or 20 mg/kg) from LD 2-21 i.p. Maternal studies were conducted from LD5 to LD21 and the offspring studies from postnatal day 2 through 90. Ketamine causes poor maternal care, with few neurochemical alterations. However, the highest dose used in this study had an antidepressant effect. Regarding the male offspring, indirect exposure to ketamine through breast milk caused few behavioral changes during infancy, but they were not permanent, as they faded in adulthood. Nevertheless, this exposure was able to cause alterations in their monoaminergic neurotransmission systems that were found in both infancy and adulthood periods.

Human milk beyond nutrition role to functional and adaptative physiological functions

Human milk contains a large amount of various proteins that contribute to the newborn's quality of life. These proteins, when digested, are transformed into peptides and amino acids that help in better absorption of nutrients from milk, some of them such as; amylase, beta- casein, lactoferrin , among others. They also have several activities, such as; immunomodulators , antihypertensives , antimicrobials, antithrombotics and others ( Lönnerdal , 2003). Human milk can be divided into three phases; colostrum, transitional milk and mature milk, and in these three different phases of milk the composition of proteins, peptides, amino acids, sugars and all other components fluctuate a lot. Many of the proteins are synthesized in the mammary gland, with some exceptions such as serum albumin which comes from the blood circulation . Currently, due to the great diversity and quantity of proteins and peptides in human milk, there are large studies on their properties such as; function and quantification of human milk proteins and peptides. With a view to better nutrition for newborns, better identification and biochemical characterization of these compounds. To this end, several steps will be carried out to isolate and characterize new peptides and proteins from human milk and the activities of the new peptides and proteins found in human milk will also be tested. These activity tests will be carried out in cell culture (cell proliferation or cell inhibition effect), blood pressure in rats (hypotensive or hypertensive effects ) and guinea pig ileum (contractile or relaxing effect). Once a peptide or protein with significant function or activity is isolated, peptidomic or cryptic analysis can then be carried out . New insights obtained with proteomics and metabolomics approaches revealed new components present in human milk including cryptides that could be generated in certain conditions by the newborn microbiome Therefore, by better characterizing human milk and its components, there will be better and greater conditions for understanding the nutrition of newborns and premature babies and a better understanding of the physiological role played by these components in relation to the development and growth of the newborn.

Progressive tremor and motor impairment in seizure-prone mutant tremor mice are associated with neurotransmitter dysfunction.

BACKGROUND: The tremor mutant mice present motor impairments comprised of whole-body tremors, ataxia, decreased exploratory behavior, and audiogenic seizures. OBJECTIVES: This study aims to investigate the development of motor dysfunction in this mutant mouse and the relationships with cortical, striatal, and cerebellar levels of GABA, glutamate, glycine, dopamine (DA), serotonin (5-HT), noradrenaline (NOR), and its metabolites. The serum cytokines levels, myelin content, and the astrocytic expression of the glial fibrillary acidic protein (GFAP) investigated the possible influence of inflammation in motor dysfunction. RESULTS: Relative to wild-type (WT) mice, the tremor mice presented: increased tremors and bradykinesia associated with postural instability, decreased range of motion, and difficulty in initiating voluntary movements directly proportional to age; reduced step length for right and left hindlimbs; reduced cortical GABA, glutamate and, aspartate levels, the DOPAC/DA and ratio and increased the NOR levels; in the striatum, the levels of glycine and aspartate were reduced while the HVA levels, the HVA/DA and 5HIAA/5-HT ratios increased; in the cerebellum the glycine, NOR and 5-HIAA levels increased. CONCLUSIONS: We suggest that the motor disturbances resulted mainly from the activation of the indirect striatal inhibitory pathway to the frontal cortex mediated by GABA, glutamate, and aspartate, reducing the dopaminergic activity at the prefrontal cortex, which was associated with the progressive tremor. The reduced striatal and increased cerebellar glycine levels could be partially responsible for the mutant tremor motor disturbances.

Postpartum depression in rats causes poor maternal care and neurochemical alterations on dams and long-lasting impairment in sociability on the offspring.

Postpartum depression is a mentally disabling disease with multifactorial etiology that affects women worldwide. It can also influence child development and lead to behavioral and cognitive alterations. Despite the high prevalence, the disease is underdiagnosed and poorly studied. To study the postpartum depression caused by maternal separation model in rats, dams were separated from their litter for 3 h daily starting from lactating day (LD) 2 through LD12. Maternal studies were conducted from LD5 to LD21 and the offspring studies from postnatal day (PND) 2 through PND90. The stress caused by the dam-offspring separation led to poor maternal care and a transient increase in anxiety in the offspring detected during infancy. The female offspring also exhibited a permanent impairment in sociability during adult life. These changes were associated with neurochemical alterations in the prefrontal cortex and hippocampus, and low TSH concentrations in the dams, and in the hypothalamus, hippocampus and striatum of the offspring. These results indicate that the postpartum depression resulted in a depressive phenotype, changes in the brain neurochemistry and in thyroid economy that remained until the end of lactation. Changes observed in the offspring were long-lasting and resemble what is observed in children of depressant mothers.

Autism spectrum disorder: history, concept and future perspective

The article narrates a brief history about the first possible descriptions of autism spectrum disorder (ASD) until the publication of Leo Kanner and Hans Asperger, then reports the evolution of its definition and concept, contextualizing its first inclusion in the ICD (International Statistical Classification of Diseases and Health related problems) and DMS (Diagnostic and statistical Manual of mental disorders) up to its latest versions. It discusses the clinical picture characterized by heterogeneous manifestation and associated comorbidities. This article also presents the weight of the contribution of genetic and environmental factors in the etiology of the disorder, the diagnosis based on clinical observation and absence of biomarkers, discussions th and efficacy and limitation of pharmacological treatment and pedagogical approaches, similarly exposes a possible research strand for ASD, developed from the production of biobanks as a source of investigation of symptoms, genetic alterations, physiological dysfunctions with the objective of identifying subgroups of individuals with ASD and thus enable the targeting of individualized and more effective interventions.

Behavioral Effects of Extracts and Compounds Isolated from Erythrina Velutina (Mulungu) in Rats

In many countries and also Brazil, the extracts or infusions of fresh plants are used to treat common infections or diseases, mainly in the countryside and among the indigenous people. The popular knowledge of the medicinal plants contributes a lot to the benefit of the human health, and directly could help for new discoveries of medicines. The antinociceptive effect is an important target for new active compounds to be searched, in part due to the increase in human life expectation, on the other hand for new cheaper compounds to the low income population, and finally, with new properties or less side effects. In the current work, extracts obtained from Erythrina velutina seeds, commonly used against snake bites, were tested for the capacity to neutralize the nociceptive effects induced by the hot plate test and anxiety behavior with combination of the open field and the elevated plus maze. Tested animals (rats) with different extracts of seed demonstrated analgesic effect with the animal on hot plate. The animals also increased wandering in the open field and even the numbers of entries and the time spent in the open arms of the elevated plus maze. That demonstrated that lesser anxiety levels allow longer and more frequent exploration periods of the open arms, suggesting that Erythrina velutina has strong anxiolytic properties compared to the control anxiolytic diazepam, it could serve as a new approach for the treatment anxiety.

New methodological approach for coagulation assays using chicken plasma intrinsic properties

Background: Sensitivity of classical coagulation assays by using mammalian plasmas to pro‐ and anticoagulant compounds includ ing venom or toxins occurs on a microscale level (micrograms). Al though it improves responses to agonists, recalcification triggers a relatively fast thrombin formation process. The Recalcification Time (RT) of factor XII- deficient Chicken Plasma (CP) is comparatively long (≥1800 seconds) when compared to human plasma or others. Our objective was to compare its sensitivity with that presented by human plasma samples to Unfractionated Heparin (UH), a pro totype anticoagulant compound, under similar conditions through rotational thromboelastometry. Methods: To find doses of UH sufficient enough to prolong the Clotting Time (CT) parameter of these activated plasmas to values within their normal RT ranges. Results: In total, 0.0065±0.0009 IU of UH (n=6) was detected in 260µL of CP samples, but only 0.125±0.012 IU of UH was sufficient to induce a similar effect in activated human plasma samples. Conclusion: The higher sensitivity of CP to anticoagulants could be useful for (a) detection of anticoagulant compounds in substanc es of unknown origin; (b) purification procedures of anticoagulant toxins from crude animal venoms and (c) determination of relative potencies of agonists and their selective antagonists such as phar maceutical agents, antivenoms or natural inhibitors of venom tox ins with a better result in kinetic clothing parameters

Searching for biomarkers candidates of autism spectrum disorder with metabolic disorders evidences for a possible role of proteins and amino acids content in urine

Background: Autism Spectrum Disorder (ASD) is characterized by conditions involving areas of social interaction, communication and behavior, as well as sensory sensitivity. Studies have reported an association of ASD with al terations in protein and amino acid metabolism. The aim of this study was to identify the profile of proteins and amino acids in the urine of children with ASD. Methods: Prospective cross-sectional study with case-control design. The cases were male children (n=22) with ASD, aged 3 to 10 years, and the control group was formed by neuro-typical children (n=22), matched for sex and age. The determination of the amount and composition of proteins was performed by the Bradford method and the determination of the amount and composition of amino acids by ultra-efficient liquid chromatography (CLUE). Results: Alterations in protein and amino acid concentrations of arginine, glycine, leucine, threonine, aspartic acid, alanine, histidine, and tyrosine were identified in the urine of children with ASD. The abnormal levels of proteins and amino acids may be related to several symptoms observed in people with ASD. Conclusion: The concentration of total protein and amino acid profile in urine are good candidates as biomarkers for individuals with ASD.

Nutritional aspects related with casein and gluten comsumption in autism spectrum disorder ASD

The etyology of Autism Spectrum Disorder (ASD) is unknown, involves a complex interaction between multiple and varied susceptible genes, epygenetic and environmental factors. The diagnosis is made through clinical evaluation First-line therapies are psychosocial treatments and educational interventions. On average 30% of people and with ASD consumes some drug or supplement. The options and effectiveness of the treatments are limited and therefore several lines of alternative treatment have emerged. The use of dietary restriction to reduce behavioral symptoms is widespread, with the most popular being the "theory of excess opioid peptides which postulates that the consumption of gluten and casein contributes to the worsening of symptoms and a diet free of these proteins improves the clinical picture. Despite many data presented in the literature, there are still doubts about the mechanisms involved as well as about dietary efficacy For all of the above, the topical review will address the opioid system, opioid peptides derived from gluten and casein, changes in the digestive tract of individuals with ASD, history of the onset of the theory, physiological mechanisms involved, brief description of the scientific literature, on the subject and the perspectives as a therapeutic instrument.

Ketamine causes poor maternal care in rats with postpartum depression and leads to few behavioral and neurochemical alterations on male offspring

Ketamine is an anesthetic drug that also has antidepressant properties, with quick action. Despite the great number of studies showing its effectiveness as a treatment for major depression, there is little information about its effects on postpartum depression, as pharmacological treatments bring risks to the health of both mother and child. Thus, this study aimed to evaluate the effects of prolonged treatment with subanesthetic doses of ketamine in a rat model of postpartum depression. Female dams were induced to postpartum depression by the maternal separation model from lactating day (LD) 2 to 12. They were divided into four groups: one control and three experimental groups, which were treated with different doses of ketamine (5, 10 or 20 mg/kg) from LD 2 to 21 i.p. Maternal studies were conducted from LD5 to LD21 and the offspring studies from postnatal day 2 through 90. Ketamine causes poor maternal care, with few neurochemical alterations. However, the highest dose used in this study had an antidepressant effect. Regarding the male offspring, indirect exposure to ketamine through breast milk caused few behavioral changes during infancy, but they were not permanent, as they faded in adulthood. Nevertheless, this exposure was able to cause alterations in their monoaminergic neurotransmission systems that were found in both infancy and adulthood periods.

Progressive tremor and motor impairment in seizure-prone mutant tremor mice are associated with neurotransmitter dysfunction

Background The tremor mutant mice present motor impairments comprised of whole-body tremors, ataxia, decreased exploratory behavior, and audiogenic seizures. Objectives This study aims to investigate the development of motor dysfunction in this mutant mouse and the relationships with cortical, striatal, and cerebellar levels of GABA, glutamate, glycine, dopamine (DA), serotonin (5-HT), noradrenaline (NOR), and its metabolites. The serum cytokines levels, myelin content, and the astrocytic expression of the glial fibrillary acidic protein (GFAP) investigated the possible influence of inflammation in motor dysfunction. Results Relative to wild-type (WT) mice, the tremor mice presented: increased tremors and bradykinesia associated with postural instability, decreased range of motion, and difficulty in initiating voluntary movements directly proportional to age; reduced step length for right and left hindlimbs; reduced cortical GABA, glutamate and, aspartate levels, the DOPAC/DA and ratio and increased the NOR levels; in the striatum, the levels of glycine and aspartate were reduced while the HVA levels, the HVA/DA and 5HIAA/5-HT ratios increased; in the cerebellum the glycine, NOR and 5-HIAA levels increased. Conclusions We suggest that the motor disturbances resulted mainly from the activation of the indirect striatal inhibitory pathway to the frontal cortex mediated by GABA, glutamate, and aspartate, reducing the dopaminergic activity at the prefrontal cortex, which was associated with the progressive tremor. The reduced striatal and increased cerebellar glycine levels could be partially responsible for the mutant tremor motor disturbances.

Postpartum depression in rats causes poor maternal care and neurochemical alterations on dams and long-lasting impairment in sociability on the offspring

Postpartum depression is a mentally disabling disease with multifactorial etiology that affects women worldwide. It can also influence child development and lead to behavioral and cognitive alterations. Despite the high prevalence, the disease is underdiagnosed and poorly studied. To study the postpartum depression caused by maternal separation model in rats, dams were separated from their litter for 3 h daily starting from lactating day (LD) 2 through LD12. Maternal studies were conducted from LD5 to LD21 and the offspring studies from postnatal day (PND) 2 through PND90. The stress caused by the dam-offspring separation led to poor maternal care and a transient increase in anxiety in the offspring detected during infancy. The female offspring also exhibited a permanent impairment in sociability during adult life. These changes were associated with neurochemical alterations in the prefrontal cortex and hippocampus, and low TSH concentrations in the dams, and in the hypothalamus, hippocampus and striatum of the offspring. These results indicate that the postpartum depression resulted in a depressive phenotype, changes in the brain neurochemistry and in thyroid economy that remained until the end of lactation. Changes observed in the offspring were long-lasting and resemble what is observed in children of depressant mothers.

Long-Term Follow-Up on Bilateral Posterior Hypothalamic Deep Brain Stimulation for Treating Refractory Aggressive Behavior in a Patient with Cri du Chat Syndrome: Analysis of Clinical Data, Intraoperative Microdialysis, and Imaging Connectomics.

Posterior hypothalamic-deep brain stimulation (pHyp-DBS) has been reported as a successful treatment for reducing refractory aggressive behaviors in patients with distinct primary diagnoses. Here, we report on a patient with cri du chat syndrome presenting severe self-injury and aggressive behaviors toward others, who was treated with pHyp-DBS. Positive results were observed at long-term follow-up in aggressive behavior and quality of life. Intraoperative microdialysis and imaging connectomics analysis were performed to investigate possible mechanisms of action. Our results suggest the involvement of limbic and motor areas and alterations in main neurotransmitter levels in the targeted area that are associated with positive results following treatment.

Effect of Subthalamic Stimulation and Electrode Implantation in the Striatal Microenvironment in a Parkinson's Disease Rat Model.

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is considered the gold-standard treatment for PD; however, underlying therapeutic mechanisms need to be comprehensively elucidated, especially in relation to glial cells. We aimed to understand the effects of STN-microlesions and STN-DBS on striatal glial cells, inflammation, and extracellular glutamate/GABAergic concentration in a 6-hydroxydopamine (6-OHDA)-induced PD rat model. Rats with unilateral striatal 6-OHDA and electrodes implanted in the STN were divided into two groups: DBS OFF and DBS ON (5 days/2 h/day). Saline and 6-OHDA animals were used as control. Akinesia, striatal reactivity for astrocytes, microglia, and inflammasome, and expression of cytokines, cell signaling, and excitatory amino acid transporter (EAAT)-2 were examined. Moreover, striatal microdialysis was performed to evaluate glutamate and GABA concentrations. The PD rat model exhibited akinesia, increased inflammation, glutamate release, and decreased glutamatergic clearance in the striatum. STN-DBS (DBS ON) completely abolished akinesia. Both STN-microlesion and STN-DBS decreased striatal cytokine expression and the relative concentration of extracellular glutamate. However, STN-DBS inhibited morphological changes in astrocytes, decreased inflammasome reactivity, and increased EAAT2 expression in the striatum. Collectively, these findings suggest that the beneficial effects of DBS are mediated by a combination of stimulation and local microlesions, both involving the inhibition of glial cell activation, neuroinflammation, and glutamate excitotoxicity.

Long-term follow-up on bilateral posterior hypothalamic deep brain stimulation for treating refractory aggressive behavior in a patient with Cri du chat syndrome: analysis of clinical data, intraoperative microdialysis, and imaging connectomics

Posterior hypothalamic-deep brain stimulation (pHyp-DBS) has been reported as a successful treatment for reducing refractory aggressive behaviors in patients with distinct primary diagnoses. Here, we report on a patient with cri du chat syndrome presenting severe self-injury and aggressive behaviors toward others, who was treated with pHyp-DBS. Positive results were observed at long-term follow-up in aggressive behavior and quality of life. Intraoperative microdialysis and imaging connectomics analysis were performed to investigate possible mechanisms of action. Our results suggest the involvement of limbic and motor areas and alterations in main neurotransmitter levels in the targeted area that are associated with positive results following treatment.

Effect of subthalamic stimulation and electrode implantation in the striatal microenvironment in a parkinson’s disease rat model

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is considered the goldstandard treatment for PD; however, underlying therapeutic mechanisms need to be comprehensively elucidated, especially in relation to glial cells. We aimed to understand the effects of STN-microlesions and STN-DBS on striatal glial cells, inflammation, and extracellular glutamate/GABAergic concentration in a 6-hydroxydopamine (6-OHDA)-induced PD rat model. Rats with unilateral striatal 6-OHDA and electrodes implanted in the STN were divided into two groups: DBS OFF and DBS ON (5 days/2 h/day). Saline and 6-OHDA animals were used as control. Akinesia, striatal reactivity for astrocytes, microglia, and inflammasome, and expression of cytokines, cell signaling, and excitatory amino acid transporter (EAAT)-2 were examined. Moreover, striatal microdialysis was performed to evaluate glutamate and GABA concentrations. The PD rat model exhibited akinesia, increased inflammation, glutamate release, and decreased glutamatergic clearance in the striatum. STN-DBS (DBS ON) completely abolished akinesia. Both STN-microlesion and STN-DBS decreased striatal cytokine expression and the relative concentration of extracellular glutamate. However, STN-DBS inhibited morphological changes in astrocytes, decreased inflammasome reactivity, and increased EAAT2 expression in the striatum. Collectively, these findings suggest that the beneficial effects of DBS are mediated by a combination of stimulation and local microlesions, both involving the inhibition of glial cell activation, neuroinflammation, and glutamate excitotoxicity.

Dopaminergic metabolism is affected by intracerebral injection of Tb II-I isolated from Tityus bahiensis scorpion venom

Tb II-I isolated from Tityus bahiensis venom causes epileptic-discharges when injected into the hippocampus of rats. The involvement of neurotransmitters in this activity was investigated. Our results demonstrated that Tb II-I increases the concentrations of dopamine metabolite but does not alter other neurotransmitters. Thus, dopaminergic system seems to be partially responsible for the convulsive process. Specific action on particular neurotransmitter can make this toxin a useful tool to better understand the functioning of the system.

Involvement of von Willebrand factor and botrocetin in the thrombocytopenia induced by Bothrops jararaca snake venom.

Patients bitten by snakes consistently manifest a bleeding tendency, in which thrombocytopenia, consumption coagulopathy, mucous bleeding, and, more rarely, thrombotic microangiopathy, are observed. Von Willebrand factor (VWF) is required for primary hemostasis, and some venom proteins, such as botrocetin (a C-type lectin-like protein) and snake venom metalloproteinases (SVMP), disturb the normal interaction between platelets and VWF, possibly contributing to snakebite-induced bleedings. To understand the relationship among plasma VWF, platelets, botrocetin and SVMP from Bothrops jararaca snake venom (BjV) in the development of thrombocytopenia, we used (a) Wistar rats injected s.c. with BjV preincubated with anti-botrocetin antibodies (ABA) and/or Na2-EDTA (a SVMP inhibitor), and (b) VWF knockout mice (Vwf-/-) injected with BjV. Under all conditions, BjV induced a rapid and intense thrombocytopenia. In rats, BjV alone reduced the levels of VWF:Ag, VWF:CB, high molecular weight multimers of VWF, ADAMTS13 activity, and factor VIII. Moreover, VWF:Ag levels in rats that received BjV preincubated with Na2-EDTA and/or ABA tended to recover faster. In mice, BjV caused thrombocytopenia in both Vwf-/- and C57BL/6 (background control) strains, and VWF:Ag levels tended to decrease in C57BL/6, demonstrating that thrombocytopenia was independent of the presence of plasma VWF. These findings showed that botrocetin present in BjV failed to affect the extent or the time course of thrombocytopenia induced by envenomation, but it contributed to decrease the levels and function of plasma VWF. Thus, VWF alterations during B. jararaca envenomation are an ancillary event, and not the main mechanism leading to decreased platelet counts.

Directional Deep Brain Stimulation of the Posteromedial Hypothalamus for Refractory Intermittent Explosive Disorder: A Case Series Using a Novel Neurostimulation Device and Intraoperative Microdialysis.

BACKGROUND: Intermittent explosive disorder (IED) is a psychiatric disorder characterized by recurrent outbursts of aggressive behavior. Deep brain stimulation (DBS) in the posteromedial nucleus of the hypothalamus (pHyp) is an alternative therapy for extreme cases and shows promising results. Intraoperative microdialysis can help elucidate the neurobiological mechanism of pHyp-DBS. We sought to evaluate efficacy and safety of pHyp-DBS using 8-contact directional leads in patients with refractory IED (rIED) and the accompanying changes in neurotransmitters. METHODS: This was a prospective study in which patients with a diagnosis of rIED were treated with pHyp-DBS for symptom alleviation. Bilateral pHyp-DBS was performed with 8-contact directional electrodes. Follow-up was performed at 3, 6, and 12 months after surgery. RESULTS: Four patients (3 men, mean age 27 ± 2.8 years) were included. All patients were diagnosed with rIED and severe intellectual disability. Two patients had congenital rubella, one had a co-diagnosis of infantile autism, and the fourth presented with drug-resistant epilepsy. There was a marked increase in the levels of gamma-aminobutyric acid and glycine during intraoperative stimulation. The average improvement in aggressive behavior in the last follow-up was 6 points (Δ: 50%, P = 0.003) while also documenting an important improvement of the Short Form Health Survey in all domains except bodily pain. No adverse events associated with pHyp-DBS were observed. CONCLUSIONS: This is the first study to show the safety and beneficial effect of directional lead pHyp-DBS in patients with rIED and to demonstrate the corresponding mechanism of action through increases in gamma-aminobutyric acid and glycine concentration in the pHyp.

Electrical stimulation of the posterior insula induces mechanical analgesia in a rodent model of neuropathic pain by modulating GABAergic signaling and activity in the pain circuitry.

The insula has emerged as a critical target for electrical stimulation since it influences pathological pain states. We investigated the effects of repetitive electrical stimulation of the insular cortex (ESI) on mechanical nociception, and general locomotor activity in rats subjected to chronic constriction injury (CCI) of the sciatic nerve. We also studied neuroplastic changes in central pain areas and the involvement of GABAergic signaling on ESI effects. CCI rats had electrodes implanted in the left agranular posterior insular cortex (pIC), and mechanical sensitivity was evaluated before and after one or five daily consecutive ESIs (15 min each, 60 Hz, 210 µs, 1 V). Five ESIs (repetitive ESI) induced sustained mechanical antinociception from the first to the last behavioral assessment without interfering with locomotor activity. A marked increase in Fos immunoreactivity in pIC and a decrease in the anterior and mid-cingulate cortex, periaqueductal gray and hippocampus were noticed after five ESIs. The intrathecal administration of the GABAA receptor antagonist bicuculline methiodide reversed the stimulation-induced antinociception after five ESIs. ESI increased GAD65 levels in pIC but did not interfere with GABA, glutamate or glycine levels. No changes in GFAP immunoreactivity were found in this work. Altogether, the results indicate the efficacy of repetitive ESI for the treatment of experimental neuropathic pain and suggest a potential influence of pIC in regulating pain pathways partially through modulating GABAergic signaling.