Research progress and application prospect of bain microdialysis in neuropsychiatric diseases / 医学研究生学报

Brain microdialysis (BMD) is a technique for continuous, on-line and real-time quantitative analysis for collected samples and it has been widely used in the quantitative detection of neurotransmitters in the brain in recent years. BMD has broad prospects in the research of neuropsychiatric diseases, but it is limited in studies because of its complicated operation, high cost, long time consuming, individual difference and poor reproducibility of the probe. Optimizing experimental design and developing multilocus microdialysis are main directions of research. Monitoring the changes of the metabolic state of the brain microenvironment in the neuropsychiatric diseases is another prospect of BMD. This article reviews the principle, characteristics and key points of brain microdialysis, along with the relationship between neurotransmitters and neuropsychiatric diseases, and the progress of microdialysis in neuropsychiatric diseases.

Studying the central control of food intake and obesity in rats

The central nervous system regulates energy intake and expenditure through a complex network of neurotransmitters and neuromodulators. It is of great interest to understand the relevance of these systems to the physiological control of energy balance and to the disturbances of obesity. The present paper discusses some of the methods to address this field used at the laboratory of Endocrine Physiology of Universidade Federal de São Paulo. Initially, different experimental models of rat obesity are presented, namely the hypothalamic induced monosodium glutamate model, the Zucker genetic model, and the dietary model. The principles of brain microdialysis are also presented, the technique applied to obtain representative samples of the extracellular fluid of brain sites involved in feeding control. The microdialysate levels of serotonin, an important anorexigenic neurotransmitter, are determined by HPLC with electrochemical detection. The immunoblot technique (Western blot) is used to determine hypothalamic levels of proteins relevant to the anorexigenic effect of serotonin and to analyze the acute activation of the insulin signaling cascade in the hypothalamus. The final section addresses the potential applications of proteomics in the study of the central control of feeding.

O sistema nervoso central controla a ingestão e o gasto de energia por meio de um complexo circuito de neurotransmissores e neuromoduladores. É de grande interesse entender a relevância fisiológica destes sistemas e o papel que desempenham nos distúrbios da obesidade. No presente artigo, discutem-se alguns dos métodos que têm sido utilizados no laboratório de Fisiologia Endócrina da Universidade Federal de São Paulo, em estudos neste campo. Inicialmente, são apresentados alguns modelos de obesidade experimental em ratos, como a obesidade hipotalâmica induzida por glutamato monossódico, o modelo genético Zucker e também obesidades induzidas por dieta. Comenta-se, em seguida, sobre os princípios da microdiálise cerebral. Esta técnica é utilizada para obter amostras representativas do líquido extracelular de regiões cerebrais envolvidas no controle da ingestão alimentar. Os níveis de serotonina, um importante neurotransmissor anorexígeno, são medidos no dialisato por cromatografia líquida de alta pressão com detecção eletroquímica. Utiliza-se a técnica de immunoblot (Western blot) para determinar os níveis hipotalâmicos de proteínas importantes na ação anorexigênica da serotonina e também para analisar a ativação aguda da cascata de sinalização da insulina no hipotálamo. A seção final aborda o grande potencial da análise proteômica no estudo do controle central da ingestão.

Effects of preconditioning treadmill exercise on the dynamic changes of brain glutamate level after cerebral infarction in rats / 中华物理医学与康复杂志

Objective To study the effects of preconditioning treadmill exercise on excitatory amino vacid changes in rats after the cerebral infarction and the protective effects against cerebral isehemia brain injury. Methods Thirty Sprague-Dawley rats were used in this study. Twenty-five rats were subject to an operation to establish the animal model of middle cerebral artery occlusion and divided into a isehemia group, an 1-week ex- ercise group (trained in the 4th week) , a 2-week exercise group (trained in the 3rd and 4th weeks) and a 4- week exercise group (trained for 4 weeks) , while the remaining 5 rats were subject to sham operation, and served as the controls. After 4 weeks of experiment, all the the rats were fixed on stereotactie apparatus for the brain microdialysis of the striatum. Then the focal middle cerebral artery ischemia and reperfusion were made with thread oeclussion in rats and microdialysis technique was used to collect extraeellular fluid in each period of pre-ischemia, ischemia (40, 80 and 120 min), and reperfusion (40, 80, 120, 160, 200 and 240 min) to detect the changes of the excitatory amino acid. At the same time the infarction volume was also measured at 24 hours after ischemia-reperfusion of the brain. Results The difference between any two groups was significant with regard to the volume of cerebral infarction (P < 0.05). Two weeks and four weeks of the preconditioning treadmill exercise couled significantly reduce concentration of Glu excessively released due to the ischemia (P < 0.01). Conclusion At least two weeks of preconditioning treadmill exercise can inhibit the excessive release of the important excitatory amino acid neurotransmitter glutamate, to some extent, in the process of the subse- quent ischemic brain injury and during reperfusion, which might be one of the protective mechanisms of move- ment against the early isehemie brain injury.

The method of simultaneous measurement of hydroxyl free radical and monoamines neurotransmitters and their metabolites from the brain microdialysis of rats / 中国药理学通报

0.05).Conclution After at a time sampling the levels of hydroxyl free radical and monoamines neurotransmitters and their metabolites from brain micronilysis of freely moving rats during salicylate sodium-Ringer's solusion perfusion can be simultaneously measured by HPLC-ED.