ANATOMICAL ANALYSIS OF NEURONAL CIRCUITS

该项目旨在提高我们对详细电路的理解 以及它与觉醒、睡眠-觉醒周期、 以及从皮层下中继到大脑皮层的信息传递。 最近的证据表明，丘脑网状核（TRN） 参与高电压节律活动的产生， 慢波睡眠时的前脑 本研究的重点是 识别可能影响兴奋性的传入输入 TRN内的神经元，并确定关系的细节 这些传入的细胞体和树突的TRN神经元。 在过去的一年中，细胞内光转换技术 在神经元内注射荧光黄染料， 电子密度，以及随后的电子组织处理 显微镜（EM）分析完善，并确定TRN神经元， 在环境管理一级进行审查，目标如下：（a）确定 单个TRN树突不同节段上的突触 神经元，和（B），以确定是否有一些更精细的珠状 这些神经元的“树突”可能产生树-树突触 这可能有助于协调邻近TRN神经元的活动。 当在EM中检查鉴定的TRN神经元时， 在所有树突上观察到对称的突触， 突触沿着树突的长度沿着是相对恒定的。 然而，偶尔出现的树突状分支点似乎密集 由不对称突触支配，其突触前元件可以 对应于D型端子。 突触接触被观察到后， 肿胀，以及串珠状树突的收缩段， 未发现细珠状树突引起突触前 数据区.

This project seeks to improve our understanding of the detailed circuitry of the thalamus and its relation to arousal, sleep-wakefulness cycles, and information transfer from subcortical relays to the cerebral cortex. Recent evidence suggests that the reticular nucleus of the thalamus (TRN) participates in the generation of the high-voltage rhythmic activity in the forebrain during slow-wave sleep. The focus of this study is to identify the afferent inputs which might influence the excitability of neurons within the TRN and to determine the details of the relationship of these afferents to the cell bodies and dendrites of TRN neurons. During the past year, the technique of photoconverting intracellularly injected Lucifer yellow dye within neurons in order to make the label electron-dense, and the subsequent processing of tissue for electron microscopic (EM) analysis was perfected, and identified TRN neurons were examined at the EM level with the following goals: (a) to identify the synapses upon different segments of the dendrites of individual TRN neurons, and (b) to determine whether or not some of the finer beaded 'dendrites' of these neurons might give rise to dendrodendritic synapses which could serve to coordinate the activity of neighboring TRN neurons. when identified TRN neurons are examined in the EM, both asymmetric and symmetric synapses are observed upon all dendrites and the density of the synapses is relatively constant along the length of the dendrites. Occasional dendritic branch points, however, appear to be densely innervated by asymmetric synapses whose pre-synaptic element may correspond to D-type terminals. Synaptic contacts were observed upon the swollen, as well as the constricted segments of the beaded dendrites, and the fine beaded dendrites were not found to give rise to pre-synaptic profiles.