Evaluation of molecular, cellular and behavioral consequences of serotonin 1A receptor deletion

In 1998, three different research groups simultaneously reported increased anxiety-related behavior in tests of conflict in their serotonin 1a (5-HT1a) receptor knockout (KO) line with male mice being more severely affected by 5-HT1a receptor deletion than female KO. Similarly, in the hippocampus, we observed increased dendritic complexity in the stratum radiatum of CA1 pyramidal neurons in male but not in female 5-HT1a receptor KO mice. These observations prompted us to investigate gender- dependent differences of 5-HT1a receptor deletion in hippocampal-related behavioral tasks. Testing our mice in anxiety-related paradigms, we reproduced the original studies showing increased anxiety- related behavior in male 5-HT1a receptor KO mice when compared to male WT mice, but no difference between female 5-HT1a receptor KO and WT mice. Similarly, male 5-HT1a receptor KO mice were impaired in association of aversive stimuli fear conditioning paradigms. We argue that increased dendritic complexity and increased synaptic strength of CA3-CA1 synapses in the stratum radiatum impaired proper signal propagation attributed to overactivation of CA1 pyramidal neurons leading to impaired fear memory of male 5-HT1a receptor KO mice. Similar mechanisms in the ventral hippocampus are likely to have contributed to gender-dependent differences in anxiety-related behavior in our and the original studies from 1998. In this study, we started to shed light on the 5-HT1a receptor downstream signaling pathways involved in dendritogenesis of pyramidal neurons during early postnatal development. We could show that NR2B-containing NMDA receptor during development acts downstream of 5-HT1a receptor and is responsible for increased amount of branching in male 5-HT1a receptor KO mice. Conversely, protein and NR2B mRNA expression was increased in 5-HT1a receptor KO mice at P15. Although the exact signaling cascade of 5-HT1a receptor regulating NR2B-containing NMDA receptor has not been determined, CaMKII is a potential downstream effector to influence transportation and removal of NR2B-containing NMDA receptors to and from the synapse. In contrast, Erk1/2 likely acts downstream of NR2B-containing NMDA receptors and was shown to be sufficient to regulate dendritic branching. Moreover, increased NR2B-containing NMDA receptor mediated cell death via excitotoxicity during development and is likely to be involved in reduced survival of adult born neurons in the hippocampus of 5-HT1a receptor KO male. The convergence of 5-HT1a receptor signaling onto NR2B-containing NMDA receptor signaling enables estrogen to interfere with its downstream pathway via G-protein coupled estrogen receptor 1 activation resulting in normalization of branching and behavior in female 5-HT1a receptor mice. In conclusion, our data strongly suggests a hormone- regulated mechanism that by converging on NR2B-containing NMDA receptor signaling is able to normalize morphology of pyramidal neurons and behavior of female 5-HT1a receptor KO mice. Our findings provide a possible explanation for gender-dependent differences in the occurrence of mental disorders with 5-HT1a receptor abnormalities as a strong predisposing factor. -- En 1998, trois équipes de recherche ont décrit un comportement de type anxieux dans des tests de conflit pour leur souris transgéniques avec une délétion du gène pour le récepteur 5-HT1a de la sérotonine. De plus, les trois groupes rapportent un phénotype plus sévère pour le comportement anxieux chez les souris transgéniques mâles que femelles. Dans l'hippocampe, la région avec la densité de récepteur 5-HT1a la plus élevée dans le télencéphale, nous avons observé dans le stratum radiatum une complexité accrue des arborisations dendritiques des neurones pyramidaux du secteur CA1 chez les souris transgénique mâles mais pas chez les femelles. Cette observation nous a encouragés à initier cette étude sur les différences en fonction du genre utilisant les tests comportementaux en rapport avec les fonctions de l'hippocampe chez les souris déficientes pour le récepteur 5-HT1a.Testant nos souris avec des paradigmes associés à l'anxiété, nous avons reproduit les données originales montrant que les souris transgéniques mâles ont un phénotype plus sévère que les souris mâles sauvages, mais qu'aucune différence n'est observée entre les femelles sauvages et transgéniques. De même, les souris mâles déficientes pour le récepteur 5-HT1a sont handicapées dans les tests de conditionnement au stress avec des stimuli aversifs. Nous faisons l'hypothèse que l'augmentation de la complexité de l'arborisation dendritique et l'augmentation de la force du signal synaptique entres les régions CA3 et CA1 de l'hippocampe dans le stratum radiatum perturbe la propagation du signal nerveux qui conduit à l'hyperactivation des neurones du secteur CA1. Ceci conduit à une mémoire de stress altérée chez les souris mâles déficientes pour le récepteur 5-HT1a. Un mécanisme similaire dans l'hippocampe ventral contribue probablement aux différences en fonction du genre dans les tests pour le comportement de type anxieux qui ont été rapportés dans les études originales de 1998. Les mesures de protéine et de mRNA ont mis en évidence une augmentation de l'expression du récepteur NMDA contenant la sous- unité NR2B dans les souris déficientes pour le récepteur 5-HT1a à P15. Dans les cultures organotypiques d'hippocampe, nous avons commencé à disséquer les messagers secondaires à l'activation du récepteur 5-HT1a qui sont impliqués dans la régulation de la croissance dendritique des neurones pyramidaux pendant la période postnatale précoce. Nous avons démontré que les récepteurs NR2B sont en aval de l'activation du récepteur 5-HT1a et qu'ils sont impliqués dans l'accroissement du nombre de dendrites chez la souris mâle déficiente pour le récepteur 5-HT1a. Bien que la cascade de signalisation du récepteur 5-HT1a pour réguler les récepteurs NMDA contenant le NR2B ne soit pas établie, CaMKII est identifié comme un effecteur potentiel pour altérer le transport du récepteur NMDA à la synapse. D'autre part, Erk1/2 est probablement un messager en aval du NR2B du récepteur NMDA, et a été documenté comme suffisant pour réguler l'arborisation dendritique. L'augmentation de NR2B à la synapse des souris déficientes pour le récepteur 5-HT1a peut conduire à une augmentation de l'excitotoxicité dans les cellules. Nous avons observé une augmentation chez la souris déficiente pour le récepteur 5-HT1a de la mort cellulaire dans des tranches d'hippocampe stimulées, ce qui peut être en relation avec la réduction de la survie des neurones générés dans l'hippocampe de la souris mâle transgénique adulte par rapport à la souris mâle sauvage. De plus, la convergence de la signalisation du récepteur 5-HT1a sur la signalisation de la sous-unité NR2B du récepteur NMDA permet à l'oestrogène d'interférer avec sa voie de signalisation du récepteur de l'oestrogène couplé à une protéine G (GPER-1), ceci permettant à l'oestrogène de réduire la taille de l'arborisation des neurones pyramidaux de CA1 chez la femelle de la souris déficiente pour le récepteur 5-HT1a. En conclusion, nos observations suggèrent fortement qu'un mécanisme hormonal convergeant sur la voie de signalisation de la sous-unité NR2B du récepteur NMDA permet la normalisation de l'exubérance des dendrites des neurones CA1 de l'hippocampe et du comportement des souris femelles déficientes pour le récepteur 5-HT1a. Ceci donne une explication possible pour la différence en fonction du genre dans l'apparition de troubles mentaux avec les variations du récepteur 5-HT1a comme facteur de prédisposition important.

Tangential migration of neuronal precursors of glutamatergic neurons in the adult mammalian brain.

In a classic model of mammalian brain formation, precursors of principal glutamatergic neurons migrate radially along radial glia fibers whereas GABAergic interneuron precursors migrate tangentially. These migration modes have significant implications for brain function. Here we used clonal lineage tracing of active radial glia-like neural stem cells in the adult mouse dentate gyrus and made the surprising discovery that proliferating neuronal precursors of glutamatergic granule neurons exhibit significant tangential migration along blood vessels, followed by limited radial migration. Genetic birthdating and morphological and molecular analyses pinpointed the neuroblast stage as the main developmental window when tangential migration occurs. We also developed a partial "whole-mount" dentate gyrus preparation and observed a dense plexus of capillaries, with which only neuroblasts, among the entire population of progenitors, are directly associated. Together, these results provide insight into neuronal migration in the adult mammalian nervous system.

Impact of a cis-associated gene expression SNP on chromosome 20q11.22 on bipolar disorder susceptibility, hippocampal structure and cognitive performance.

BackgroundBipolar disorder is a highly heritable polygenic disorder. Recent enrichment analyses suggest that there may be true risk variants for bipolar disorder in the expression quantitative trait loci (eQTL) in the brain.AimsWe sought to assess the impact of eQTL variants on bipolar disorder risk by combining data from both bipolar disorder genome-wide association studies (GWAS) and brain eQTL.MethodTo detect single nucleotide polymorphisms (SNPs) that influence expression levels of genes associated with bipolar disorder, we jointly analysed data from a bipolar disorder GWAS (7481 cases and 9250 controls) and a genome-wide brain (cortical) eQTL (193 healthy controls) using a Bayesian statistical method, with independent follow-up replications. The identified risk SNP was then further tested for association with hippocampal volume (n = 5775) and cognitive performance (n = 342) among healthy individuals.ResultsIntegrative analysis revealed a significant association between a brain eQTL rs6088662 on chromosome 20q11.22 and bipolar disorder (log Bayes factor = 5.48; bipolar disorder P = 5.85×10(-5)). Follow-up studies across multiple independent samples confirmed the association of the risk SNP (rs6088662) with gene expression and bipolar disorder susceptibility (P = 3.54×10(-8)). Further exploratory analysis revealed that rs6088662 is also associated with hippocampal volume and cognitive performance in healthy individuals.ConclusionsOur findings suggest that 20q11.22 is likely a risk region for bipolar disorder; they also highlight the informative value of integrating functional annotation of genetic variants for gene expression in advancing our understanding of the biological basis underlying complex disorders, such as bipolar disorder.

L-Lactate protects neurons against excitotoxicity: implication of an ATP-mediated signaling cascade.

Converging experimental data indicate a neuroprotective action of L-Lactate. Using Digital Holographic Microscopy, we observe that transient application of glutamate (100 μM; 2 min) elicits a NMDA-dependent death in 65% of mouse cortical neurons in culture. In the presence of L-Lactate (or Pyruvate), the percentage of neuronal death decreases to 32%. UK5099, a blocker of the Mitochondrial Pyruvate Carrier, fully prevents L-Lactate-mediated neuroprotection. In addition, L-Lactate-induced neuroprotection is not only inhibited by probenicid and carbenoxolone, two blockers of ATP channel pannexins, but also abolished by apyrase, an enzyme degrading ATP, suggesting that ATP produced by the Lactate/Pyruvate pathway is released to act on purinergic receptors in an autocrine/paracrine manner. Finally, pharmacological approaches support the involvement of the P2Y receptors associated to the PI3-kinase pathway, leading to activation of KATP channels. This set of results indicates that L-Lactate acts as a signalling molecule for neuroprotection against excitotoxicity through coordinated cellular pathways involving ATP production, release and activation of a P2Y/KATP cascade.

Cytokine-induced sleep: Neurons respond to TNF with production of chemokines and increased expression of Homer1a in vitro.

Interactions of neurons with microglia may play a dominant role in sleep regulation. TNF may exert its somnogeneic effects by promoting attraction of microglia and their processes to the vicinity of dendrites and synapses. We found TNF to stimulate neurons (i) to produce CCL2, CCL7 and CXCL10, chemokines acting on mononuclear phagocytes and (ii) to stimulate the expression of the macrophage colony stimulating factor (M-CSF/Csf1), which leads to elongation of microglia processes. TNF may also act on neurons by affecting the expression of genes essential in sleep-wake behavior. The neuronal expression of Homer1a mRNA, increases during spontaneous and enforced periods of wakefulness. Mice with a deletion of Homer1a show a reduced wakefulness with increased non-rapid eye movement (NREM) sleep during the dark period. Recently the TNF-dependent increase of NREM sleep in the dark period of mice with CD40-induced immune activation was found to be associated with decreased expression of Homer1a. In the present study we investigated the effects of TNF and IL-1β on gene expression in cultures of the neuronal cell line HT22 and cortical neurons. TNF slightly increased the expression of Homer1a and IL-1β profoundly enhanced the expression of Early growth response 2 (Egr2). The data presented here indicate that the decreased expression of Homer1a, which was found in the dark period of mice with CD40-induced increase of NREM sleep is not due to inhibitory effects of TNF and IL-1β on the expression of Homer1a in neurons.

In cortical neurons HDAC3 suppresses RD4-dependent SMRT export

The transcriptional corepressor SMRT controls neuronal responsiveness of several transcription factors and can regulate neuroprotective and neurogenic pathways. SMRT is a multi-domain protein that complexes with HDAC3 as well as being capable of interactions with HDACs 1, 4, 5 and 7. We previously showed that in rat cortical neurons, nuclear localisation of SMRT requires histone deacetylase activity: Inhibition of class I/II HDACs by treatment with trichostatin A (TSA) causes redistribution of SMRT to the cytoplasm, and potentiates the activation of SMRT-repressed nuclear receptors. Here we have sought to identify the HDAC(s) and region(s) of SMRT responsible for anchoring it in the nucleus under normal circumstances and for mediating nuclear export following HDAC inhibition. We show that in rat cortical neurons SMRT export can be triggered by treatment with the class I-preferring HDAC inhibitor valproate and the HDAC2/3-selective inhibitor apicidin, and by HDAC3 knockdown, implicating HDAC3 activity as being required to maintain SMRT in the nucleus. HDAC3 interaction with SMRT's deacetylation activation domain (DAD) is known to be important for activation of HDAC3 deacetylase function. Consistent with a role for HDAC3 activity in promoting SMRT nuclear localization, we found that inactivation of SMRT's DAD by deletion or point mutation triggered partial redistribution of SMRT to the cytoplasm. We also investigated whether other regions of SMRT were involved in mediating nuclear export following HDAC inhibition. TSA- and valproate-induced SMRT export was strongly impaired by deletion of its repression domain-4 (RD4). Furthermore, over-expression of a region of SMRT containing the RD4 region suppressed TSA-induced export of full-length SMRT. Collectively these data support a model whereby SMRT's RD4 region can recruit factors capable of mediating nuclear export of SMRT, but whose function and/or recruitment is suppressed by HDAC3 activity. Furthermore, they underline the fact that HDAC inhibitors can cause reorganization and redistribution of corepressor complexes.

Intravitreal docosahexaenoic acid in a rabbit model: preclinical safety assessment

Purpose The purpose of the present study was to evaluate the retinal toxicity of a single dose of intravitreal docosahexaenoic acid (DHA) in rabbit eyes over a short-term period. Methods Sixteen New Zealand albino rabbits were selected for this pre-clinical study. Six concentrations of DHA (Brudy Laboratories, Barcelona, Spain) were prepared: 10 mg/50 µl, 5 mg/50 µl, 2'5 mg/50 µl, 50 µg/50 µl, 25 µg/50 µl, and 5 µg/50 µl. Each concentration was injected intravitreally in the right eye of two rabbits. As a control, the vehicle solution was injected in one eye of four animals. Retinal safety was studied by slit-lamp examination, and electroretinography. All the rabbits were euthanized one week after the intravitreal injection of DHA and the eyeballs were processed to morphologic and morphometric histological examination by light microscopy. At the same time aqueous and vitreous humor samples were taken to quantify the concentration of omega-3 acids by gas chromatography. Statistical analysis was performed by SPSS 21.0. Results Slit-lamp examination revealed an important inflammatory reaction on the anterior chamber of the rabbits injected with the higher concentrations of DHA (10 mg/50 µl, 5 mg/50 µl, 2'5 mg/50 µ) Lower concentrations showed no inflammation. Electroretinography and histological studies showed no significant difference between control and DHA-injected groups except for the group injected with 50 µg/50 µl. Conclusions Our results indicate that administration of intravitreal DHA is safe in the albino rabbit model up to the maximum tolerated dose of 25 µg/50 µl. Further studies should be performed in order to evaluate the effect of intravitreal injection of DHA as a treatment, alone or in combination, of different retinal diseases.

In vivo co-ordinated interactions between inhibitory systems to control glutamate mediated hippocampal excitability.

We present an overview of the long-term adaptation of hippocampal neurotransmission to cholinergic and GABAergic deafferentation caused by excitotoxic lesion of the medial septum. Two months after septal microinjection of 2.7 nmol a -amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA), a 220% increase of GABA A receptor labelling in the hippo- campal CA3 and the hilus was shown, and also changes in hippocampal neurotransmission characterised by in vivo microdialysis and HPLC. Basal amino acid and purine extra- cellular levels were studied in control and lesioned rats. In vivo effects of 100 m M KCl perfusion and adenosine A 1 receptor blockade with 1,3-dipropyl- 8-cyclopentylxanthine (DPCPX) on their release were also investigated. In lesioned animals GABA, glutamate and glutamine basal levels were decreased and taurine, adenosine and uric acid levels increased. A similar response to KCl infusion occurred in both groups except for GABA and glutamate, which release decreased in lesioned rats. Only in lesioned rats, DPCPX increased GABA basal level and KCl-induced glutamate release, and decreased glutamate turnover. Our results evidence that an excitotoxic septal lesion leads to increased hippocampal GABA A receptors and decreased glutamate neurotransmis- sion. In this situation, a co-ordinated response of hippocampal retaliatory systems takes place to control neuron excitability.

3,4-Methylenedioxymethamphetamine enhances kainic acid convulsive susceptibility

Abstract Kainic acid (KA) causes seizures and neuronal loss in the hippocampus. The present study investigated whether a recreational schedule of 3,4-methylenedioxymethamphetamine (MDMA) favours the development of a seizure state in a model of KA-induced epilepsy and potentiates the toxicity profile of KA (20 or 30 mg/kg). Adolescent male C57BL/6 mice received saline or MDMA t.i.d. (s.c. every 3 h), on 1 day a week, for 4 consecutive weeks. Twenty-four hours after the last MDMA exposure, the animals were injected with saline or KA (20 or 30 mg/kg). After this injection, we evaluated seizures, hippocampal neuronal cell death, microgliosis, astrogliosis, and calcium binding proteins. MDMA pretreatment, by itself, did not induce neuronal damage but increased seizure susceptibility in all KA treatments and potentiated the presence of Fluoro-Jade-positive cells in CA1. Furthermore, MDMA, like KA, significantly decreased parvalbumin levels in CA1 and dentate gyrus, where it potentiated the effects of KA. The amphetamine derivative also promoted a transient decrease in calbindin and calretinin levels, indicative of an abnormal neuronal discharge. In addition, treatment of cortical neurons with MDMA (1050 μM) for 6 or 48 h significantly increased basal Ca2 +, reduced basal Na+ levels and potentiated kainate response. These results indicate that MDMA potentiates KA-induced neurodegeneration and also increases KA seizure susceptibility. The mechanism proposed includes changes in Calcium Binding Proteins expression, probably due to the disruption of intracellular ionic homeostasis, or/and an indirect effect through glutamate release.

3,4-Methylenedioxymethamphetamine enhances kainic acid convulsive susceptibility

Abstract Kainic acid (KA) causes seizures and neuronal loss in the hippocampus. The present study investigated whether a recreational schedule of 3,4-methylenedioxymethamphetamine (MDMA) favours the development of a seizure state in a model of KA-induced epilepsy and potentiates the toxicity profile of KA (20 or 30 mg/kg). Adolescent male C57BL/6 mice received saline or MDMA t.i.d. (s.c. every 3 h), on 1 day a week, for 4 consecutive weeks. Twenty-four hours after the last MDMA exposure, the animals were injected with saline or KA (20 or 30 mg/kg). After this injection, we evaluated seizures, hippocampal neuronal cell death, microgliosis, astrogliosis, and calcium binding proteins. MDMA pretreatment, by itself, did not induce neuronal damage but increased seizure susceptibility in all KA treatments and potentiated the presence of Fluoro-Jade-positive cells in CA1. Furthermore, MDMA, like KA, significantly decreased parvalbumin levels in CA1 and dentate gyrus, where it potentiated the effects of KA. The amphetamine derivative also promoted a transient decrease in calbindin and calretinin levels, indicative of an abnormal neuronal discharge. In addition, treatment of cortical neurons with MDMA (1050 μM) for 6 or 48 h significantly increased basal Ca2 +, reduced basal Na+ levels and potentiated kainate response. These results indicate that MDMA potentiates KA-induced neurodegeneration and also increases KA seizure susceptibility. The mechanism proposed includes changes in Calcium Binding Proteins expression, probably due to the disruption of intracellular ionic homeostasis, or/and an indirect effect through glutamate release.

Production of policlonal antisera specific to plant viruses by rabbit oral immunization

Serological techniques are of great importance for plant virus identification and characterization. The major limiting factor for using these techniques for plant virus identification is the requirement of a good virus purified preparation to be used in immunizing animals for antiserum production. In the present study, two New Zealand rabbits were orally immunized with extracts from cowpea (Vigna unguiculata) plants systemically infected with Cowpea severe mosaic virus (CPSMV) and with extracts from papaya (Carica papaya) infected with Papaya lethal yellowing virus (PLYV). The leaf extracts were prepared in saline solution 0.15 M in the rate of 1:1 (w/v) and clarified by a centrifugation of 10,000 g for 10 min. The clarified extracts containing the viruses were orally administered to the New Zealand rabbits in two series of five daily doses of 1.0 ml each. The obtained policlonal antisera were shown to be very specific to their respective viruses in double immunodiffusion and indirect ELISA. These seem to be the first antisera specific for plant virus obtained by rabbit oral immunization. The results open up some possibilities for producing antisera to plant viruses of difficult purification. It is a simple, fast and inexpensive method for production of antisera for plant viruses when compared to the traditional techniques that involve rabbit injections with purified virus preparations.

PET and MR imaging in Parkinson’s disease patients with cognitive impairment. A study of dopaminergic dysfunction, amyloid deposition, cortical hypometabolism and brain atrophy

Parkinson’s disease (PD) is the second most common neurodegenerative disorder. It is characterized by a severe loss of substantia nigra dopaminergic neurons leading to dopamine depletion in the striatum. PD affects movement, producing motor symptoms such as rigidity, tremor and bradykinesia. Non-motor symptoms include autonomic dysfunction, neurobehavioral problems and cognitive impairment, which may lead to dementia. The pathophysiological basis of cognitive impairment and dementia in PD is unclear. The aim of this thesis was to study the pathophysiological basis of cognitive impairment and dementia in PD. We evaluated the relation between frontostriatal dopaminergic dysfunction and the cognitive symptoms in PD patients with [18F]Fdopa PET. We also combined [C]PIB and [¹⁸F]FDG PET and magnetic resonance imaging in PD patients with and without dementia. In addition, we analysed subregional striatal [¹⁸F]Fdopa PET data to find out whether a simple ratio approach would reliably separate PD patients from healthy controls. The impaired dopaminergic function of the frontostriatal regions was related to the impairment in cognitive functions, such as memory and cognitive processing in PD patients. PD patients with dementia showed an impaired glucose metabolism but not amyloid deposition in the cortical brain regions, and the hypometabolism was associated with the degree of cognitive impairment. PD patients had atrophy, both in the prefrontal cortex and in the hippocampus, and the hippocampal atrophy was related to impaired memory. A single 15-min scan 75 min after a tracer injection seemed to be sufficient for separating patients with PD from healthy controls in a clinical research environment. In conclusion, the occurrence of cognitive impairment and dementia in PD seems to be multifactorial and relates to changes, such as reduced dopaminergic activity, hypometabolism, brain atrophy and rarely to amyloid accumulation.

Assessment of NADPH-diaphorase stained myenteric neurons of the jejunum of diabetic rats supplemented with ascorbic acid

The relation between hyperglycemia and diabetic neuropathy has already been demonstrated in some studies. Among the theories proposed for its etiology the oxidative stress stands out. The performance of nitric oxide as a link between the metabolic and vascular neuropathogenic factors that triggers the diabetic neuropathy has already been put forward. This study aimed to assess the quantification and measurements of the cell body profile area (CBPA) of NADPH-diaphorase reactive (NADPH-dp) myenteric neurons of the jejunum of diabetic rats (induced by streptozotocin) supplemented with Ascorbic Acid (AA). These changes in the myenteric neurons seem to be related to the gastrointestinal disturbances observed in diabetes mellitus (DM). Twenty male Wistar rats (Rattus norvegicus) were distributed in 4 groups (n=5): controls (C), control supplemented (CS), diabetic (D), and diabetic suplemented (DS). DM was induced by estreptozotocin (50mg/kg body wt). One week after the induction and confirmation of the DM (glycemia exam), animals of the groups CS and DS received 50mg of AA three times a week by gavage. After 90 days of experiment, the animals were anesthetized with lethal thiopental dose (40mg/kg) and the collected jejunum processed for the histochemistry NADPH-diaphorase technique. Whole-mount preparations were obtained for quantitative and morphometric analysis of the myenteric neurons. A quantity of jejunum neurons in the Group D (96±7.5) was not different (P>0.05) from Group DS (116±8.08), C (92±9.7), and CS (81±5.4), but in Group DS the quantity was higher (P<0.05) than in Group C and CS. The CBPA of neurons from Group D (189.50±2.68µm²) and DS (195.92±3.75µm²) were lower (P<0.05) than from Group C (225.13±4.37µm²) and CS (210.23±3.15µm²). The streptozotocin-induced DM did not change the jejunum-ileum area, the jejunum myenteric plexus space organization and the density of NADPH-dp neurons. The 50g AA-supplementation, three times a week, during 90 days, did not decrease hyperglycemia; however, it had a neuroprotective effect on the myenteric neurons, minimizing the increase on the CBPA of NADPH-dp neurons and increasing the amount of NADPD-dp neurons.

Celiac artery in New Zealand rabbit: anatomical study of its origin and arrangement for experimental research and surgical practice

Rabbits have been used as an experimental model in many diseases and for the study of toxicology, pharmacology and surgery in many universities. However, some aspects of their macro anatomy need a more detailed description, especially the abdominal and pelvic arterial vascular system, which has a huge variability in distribution and trajectory. Thirty cadaveric adult New Zealand rabbits, 13 male and 17 female, with an average weight and rostrum-sacral length of 2.5 kg and 40cm, respectively, were used. The thoracic aorta was cannulated and the vascular system was filled with stained latex S-65. The celiac artery and its proximal branches were dissected and lengthened in order to evidence origin and proximal ramifications. The celiac artery emerged between the 12th and 13th thoracic vertebra in 11 (36.7%) rabbits; at the level of the 13th thoracic vertebra in 6 (20%) rabbits; between the 13th thoracic vertebra and the 1st lumbar vertebra in 12 (40%) rabbits; and at the level of the 1st lumbar vertebra in only one (3.3%) rabbit. The mean length of the celiac artery was 0.5cm. The celiac artery first branch was the lienal artery, the second branch was the left gastric artery and the hepatic artery arose from the left gastric artery in all the dissected rabbits. No relation was observed between the celiac artery length and the rostrum-sacral length in rabbits. The number of left gastric and lienal artery branches and the distribution of celiac artery origin are not gender dependent.