RESUMO
In hydrocephalus, the progressive accumulation of cerebrospinal fluid (CSF) causes dilatation of the lateral ventricles affecting the third ventricle and diencephalic structures such as the hypothalamus. These structures play a key role in the regulation of several neurovegetative functions by the production of the hormones. Since endocrine disturbances are commonly observed in hydrocephalic children, we investigated the impact of progressive ventricular dilation on the hypothalamus of infant rats submitted to kaolin-induced hydrocephalus. Seven-day-old infant rats were submitted to hydrocephalus induction by kaolin 20% injection method. After 14â¯days, the animals were decapitated and brain was collected to analyze mitochondrial function, neuronal activity by acetylcholinesterase (AChE) enzyme, oxidative damage, glial activation, and, neurotransmission-related proteins and anti-apoptotic processes in the hypothalamus. The hydrocephalic animals showed reduction in respiratory rates in the States of phosphorylation (Pâ¯<â¯0.01) and non-phosphorylation (Pâ¯<â¯0.05); increase in AChE activity in both the cytosol (Pâ¯<â¯0.05) and the membrane (Pâ¯<â¯0.01); decrease in synaptophysin (Pâ¯<â¯0.05) and Bcl-2 (Pâ¯<â¯0.05) contents and; increase in protein carbonyl (Pâ¯<â¯0.01), GFAP (Pâ¯<â¯0.01) and Iba-1 (Pâ¯<â¯0.05) levels. The results demonstrate that ventricular dilation causes hypothalamic damage characterized by cholinergic dysfunction and suggests further investigation of the synthesis and secretion of hormones to generate new approaches and to assist in the treatment of hydrocephalic patients with hormonal alterations.
Assuntos
Acetilcolinesterase/metabolismo , Hidrocefalia/metabolismo , Hipotálamo/fisiopatologia , Acetilcolinesterase/fisiologia , Animais , Animais Recém-Nascidos , Encéfalo/fisiopatologia , Ventrículos Cerebrais/fisiopatologia , Modelos Animais de Doenças , Hidrocefalia/fisiopatologia , Hipotálamo/metabolismo , Caulim/efeitos adversos , Caulim/farmacologia , Ventrículos Laterais/fisiopatologia , Masculino , Neurônios , Ratos , Ratos WistarRESUMO
Adult neurogenesis occurs in the subgranular zone of the hippocampal dentate gyrus and the subventricular zone of the lateral ventricles. This process is highly regulated by intrinsic and extrinsic factors, which may control the proliferation and/or maturation of neural progenitor cells. Adult-born neurons are integrated in preexisting networks and may have functional implications for adult brain. Here we attempt to summarize relevant findings concerning the physiological role of adult neurogenesis mainly focused on the subgranular zone, and to discuss the reduced neurogenesis observed during aging and the factors that have been involved in this phenomenon. Finally, we focus on hippocampal neurogenesis in Alzheimer's disease, reviewing animal models of the disease used for the study of this process and the conclusions that have been drawn in this context.
Assuntos
Envelhecimento/fisiologia , Doença de Alzheimer/fisiopatologia , Hipocampo/fisiologia , Neurogênese , Animais , Encéfalo/fisiopatologia , Giro Denteado/fisiopatologia , Modelos Animais de Doenças , Hipocampo/fisiopatologia , Humanos , Ventrículos Laterais/fisiopatologia , Camundongos , Camundongos Transgênicos , Neurônios/fisiologia , Células-Tronco/citologiaRESUMO
Hydrocephalus is a common neurological problem in humans, usually caused by an impairment of cerebrospinal fluid (CSF) flow or absorption. A reliable induced model of chronic hydrocephalus in mice would be useful to test hypotheses using genetic mutants. Our goal was to characterize behavioral and histological changes in juvenile and young adult mice with kaolin (aluminum silicate)-induced hydrocephalus. Seven-day old and 7-8 week old mice received injection of kaolin into the cisterna magna. Behavior was assessed repeatedly. Seven or 14 days following kaolin, magnetic resonance (MR) imaging was used to assess ventricle size. In hydrocephalic mice, body weight was significantly lower than in age-matched saline-injected sham controls and the gait and posture score were impaired. Juvenile mice developed severe ventriculomegaly and had reduced corpus callosum thickness with gross white matter destruction by 14 days. Reactive astroglial change in white matter and cortex and reduced cellular proliferation in the subependymal zone were also apparent. Young adult mice developed only moderate ventricular enlargement without overt white matter destruction, although there was corpus callosum atrophy and mild astroglial reaction in white matter. Glial fibrillary acidic protein content was significantly higher in juvenile and young adult hydrocephalic mice at 7 and 14 days, but myelin basic protein content was not significantly altered. In conclusion, hydrocephalus induced by percutaneous injection of kaolin in juvenile and young adult mice is feasible. The associated periventricular alterations are essentially the same as those reported in rats of comparable ages.
Assuntos
Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Hidrocefalia/induzido quimicamente , Hidrocefalia/patologia , Caulim/toxicidade , Envelhecimento/fisiologia , Animais , Animais Recém-Nascidos , Antidiarreicos/toxicidade , Astrócitos/efeitos dos fármacos , Astrócitos/patologia , Peso Corporal/fisiologia , Encéfalo/crescimento & desenvolvimento , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/patologia , Corpo Caloso/efeitos dos fármacos , Corpo Caloso/patologia , Modelos Animais de Doenças , Proteína Glial Fibrilar Ácida/metabolismo , Gliose/induzido quimicamente , Gliose/patologia , Gliose/fisiopatologia , Hidrocefalia/fisiopatologia , Injeções Intraventriculares , Ventrículos Laterais/efeitos dos fármacos , Ventrículos Laterais/patologia , Ventrículos Laterais/fisiopatologia , Imageamento por Ressonância Magnética , Masculino , CamundongosRESUMO
We report a case of catalepsy associated with thalamic hemorrhage. A 72 year-old hypertensive woman had acute onset of right-sided weakness and speech disturbances. She was on anticoagulants because of aortic valve replacement. When postures were imposed, the patient maintained the left upper limb raised for several minutes, even in uncomfortable or bizarre positions. A CT scan of the head revealed a left thalamic hemorrhage. Cataleptic postures have been reported in few cases with acute stroke