RESUMO
Chronic ethanol consumption can produce learning and memory deficits. Brain-derived neurotrophic factor (BDNF) and its receptors affect the pathogenesis of alcoholism. In this study, we examined the expression of BDNF, tropomyosin receptor kinase B (TrkB) and p75 neurotrophin receptor (p75NTR) in the hippocampus of a dog model of chronic alcoholism and abstinence. Twenty domestic dogs (9-10 months old, 15-20 kg; 10 males and 10 females) were obtained from Harbin Medical University. A stable alcoholism model was established through ad libitum feeding, and anti-alcohol drug treatment (Zhong Yao Jie Jiu Ling, the main ingredient was the stems of watermelon; developed in our laboratory), at low- and high-doses, was carried out. The Zhong Yao Jie Jiu Ling was effective for the alcoholism in dogs. The morphology of hippocampal neurons was evaluated using hematoxylin-eosin staining. The number and morphological features of BDNF, TrkB and p75NTR-positive neurons in the dentate gyrus (DG), and the CA1, CA3 and CA4 regions of the hippocampus were observed using immunohistochemistry. One-way ANOVA was used to determine differences in BDNF, TrkB and p75NTR expression. BDNF, TrkB and p75NTR-positive cells were mainly localized in the granular cell layer of the DG and in the pyramidal cell layer of the CA1, CA3 and CA4 regions (DG>CA1>CA3>CA4). Expression levels of both BDNF and TrkB were decreased in chronic alcoholism, and increased after abstinence. The CA4 region appeared to show the greatest differences. Changes in p75NTR expression were the opposite of those of BDNF and TrkB, with the greatest differences observed in the DG and CA4 regions.
Assuntos
Animais , Masculino , Feminino , Cães , Abstinência de Álcool , Alcoolismo/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Hipocampo/química , Receptor de Fator de Crescimento Neural/metabolismo , Receptor trkB/metabolismo , Fator Neurotrófico Derivado do Encéfalo/genética , Doença Crônica , Modelos Animais de Doenças , Regulação da Expressão Gênica , Hipocampo/metabolismo , Imuno-Histoquímica , Receptor de Fator de Crescimento Neural/genética , Receptor trkB/genéticaRESUMO
OBJECTIVE@#To observe the change of c-fos protein(Fos) and nerve growth factor receptor (NGFR) staining in the brain of rat after experimental brain contusion.@*METHODS@#Immunohistochemistry of c-fos and NGFR were applied to investigate the brain contusion.@*RESULTS@#(1) The expression of Fos protein could be observed at 0.5 h after injury and then increased with the prolonging of time. By 3 h after injury, the positive staining cells could be detected massively not only in and round the wound site but also in other areas of the whole ipsilateral cortex. The stains decreased 6-12 h later and could hardly be detected 1 d after the brain contusion. The control-experiment is negative. (2) NGFR positive staining cells could be found round the wound area 1 d postlesion. At 3 d following injury, a peak of massive positively stained cells appeared both in number and in intensity, showing significant differences compare with that of 1 d after damage (P < 0.01). 5 d later the positive express declined slowly. The express in the control-rat is negative.@*CONCLUSION@#There is a rule that the expression of Fos and NGFR positive staining changes with time going after brain contusion, which will be of great value in estimation of brain injury time. Detection of Fos can be used for time deduction in earlier period after injury, while NGFR in later period. They are also very important for distinguishing between antemortem or postmortem injury.