蛋白质转导及在神经科学研究中的应用

蛋白质转导或蛋白质治疗是通过表达载体法或化学交联法将具有治疗作用的外源性蛋白质与称为蛋白质转导域的氨基酸片段相连，以非受体和非温度依赖的方式穿越细胞膜进入胞内达到治疗疾病的目的，这种内在化的异质蛋白质不仅依旧保持了原有的生物学活性和功能。而且能在保持血脑屏障完整的情况下进入脑内。目前，蛋白质转导技术除了用于转导肿瘤特异抗体和药物进行抗肿瘤治疗以及制备抗感染或抗病毒的疫苗外。也已广泛应用于神经科学和与神经疾病相关的研究。     

Optogenetics in neuroscience: what we gain from studies in mammals

Optogenetics is a newly-introduced technology in the life sciences and is gaining increasing attention.It refers to the combination of optical technologies and genetic methods to control the activity of specific cell groups in living tissue,during which high-resolution spatial and temporal manipulation of cells is achieved.Optogenetics has been applied to numerous regions,including cerebral cortex,hippocampus,ventral tegmental area,nucleus accumbens,striatum,spinal cord,and retina,and has revealed new directions of research in neuroscience and the treatment of related diseases.Since optogenetic tools are controllable at high spatial and temporal resolution,we discuss its applications in these regions in detail and the recent understanding of higher brain functions,such as reward-seeking,learning and memory,and sleep.Further,the possibilities of improved utility of this newly-emerging technology are discussed.We intend to provide a paradigm of the latest advances in neuroscience using optogenetics.     

Functional imaging studies: linking mind and basic neuroscience

OBJECTIVE: The imaging of brain activity with positron emission tomography (PET) and functional magnetic resonance imaging has assumed a central position in psychiatry. Functional imaging signals arise from changes in the neurophysiological parameters of glucose and oxygen consumption mediated by blood flow. METHOD: Recent in vivo (13)C nuclear magnetic resonance (NMR) neurochemical studies have established a quantitative coupling between the rates of glucose oxidation and glutamate neurotransmitter flux in rats and humans, thereby linking measured neurophysiological parameters to brain function. RESULTS: These results show that in the awake, resting, and unstimulated states, 70%-80% of brain energy consumption is devoted to the same glutamate/glutamine neurotransmitter signaling as are the small percentages stimulated by tasks. Furthermore, in anesthetized animals, in which unstimulated activity is reduced, the total signal rather than a particular increment is required for a response. CONCLUSIONS: On this basis, the total signal, as well as the difference in the signal, measures cortical neurotransmitter flux. The total signal in a region therefore contains valuable information about required brain activity. Although signal change is often more easily measured, certain PET and (13)C NMR methods can quantify total regional signal activity and thereby provide another measure of neurotransmitter activity.