CHOLINERGIC INFLUENCES ON CORTICOTHALAMIC TRANSMISSION

胆碱能对皮质丘脑传递的影响

基本信息

批准号：
6092053
负责人：
MARTHA E BICKFORD
金额：
$ 5万
依托单位：
UNIVERSITY OF LOUISVILLE
依托单位国家：
美国
项目类别：
财政年份：
1995
资助国家：
美国
起止时间：
1995-09-30 至 2000-09-29
项目状态：
已结题

项目摘要

DESCRIPTION: The research explores the mechanisms underlying selective visual attention. Thalamic gating of sensory signals is considered to be a fundamental mechanism for regulating attention. The proposed experiments employ complementary anatomical and physiological approaches to examine in the cat the organization of connections between cortex and the pulvinar/lateral posterior (LP) complex, and how these connections are influenced by a projection from cholinergic cells of the of the parabrachial region (PBR). The proposed experiments will test the prediction that shifts in attention are regulated by the dampening or amplification of cortical inputs to the pulvinar and LP nuclei. Anatomical experiments involving cortical injections of the neuroanatomical tracer biocytin will test the hypothesis (#1) that Layer V feedforward and layer VI feedback cortical connections are present in the pulvinar/LP complex. Light and electron microscopic techniques will be used to determine the distribution and postsynaptic targets of type I and type II cortical terminals and will test the prediction that in the pulvinar/LP complex, type II cortical terminals supplant the position occupied by primary sensory afferents in the "specific" thalamic nuclei. In separate experiments in vitro slice preparations, intracellular recordings of pulvinar/LP cells will be obtained to test the hypothesis (#2) that pulvinar/LP cells have distinct cellular responses to selective stimulation of type I and type II cortical terminals. The postsynaptic potentials involved will be characterized (eg. NMDA, non NMDA, metabotropic) and the ability to facilitate responses by high frequency stimulation will be evaluated. Pre and postembedding immunocytochemistry will be used to stain cholinergic terminals and profiles that contain GABA and will test the hypothesis (#3) that PBR terminals in the pulvinar/LP complex are positioned to selectively influence feedforward cortical input. Lastly, ACh will be applied to pulvinar/LP cells in vitro to test (#4) whether ACh enhances the responses of pulvinar/LP cells to cortical input. Collectively, these experiments will lay the groundwork for future physiological and/or behavioral studies of the cholinergic influences on selective attention.

描述：研究探讨了选择性的机制视觉关注。感觉信号的丘脑门控被认为成为调节注意力的基本机制。提议实验采用互补的解剖学和生理方法在猫中检查皮质与皮质之间的联系的组织 pulvinar/侧面后（LP）复合物以及这些连接如何受到胆碱能细胞投射的影响副型区域（PBR）。提出的实验将测试注意力转移的预测受阻尼或将皮质输入放大到pulvinar和LP核。涉及皮质注射的解剖学实验神经解剖示踪剂生物细胞将检验该层的假设（＃1） v feedforward和第六层反馈皮层连接中存在 Pulvinar/LP复合物。光和电子微观技术将用于确定类型的分布和突触后靶标 I和II型皮质终端，将测试以下预测 Pulvinar/LP复合物，II型皮质末端取代在“特定”中被主要感官传入所占据的位置丘脑核。在单独的体外切片制剂中，将获得Pulvinar/LP细胞的细胞内记录以进行测试 pulvinar/lp细胞具有独特的细胞的假设（＃2）对选择性刺激I型和II型皮质的反应终端。涉及的突触后电位将被表征（例如NMDA，非NMDA，代谢性）和促进的能力将评估高频刺激的反应。 pre and 后置免疫细胞化学将用于染色胆碱能包含GABA的终端和轮廓，并将检验假设（＃3）PULVINAR/LP复合物中的PBR终端位于有选择地影响前馈皮层输入。最后，ACH将是在体外应用于Pulvinar/LP细胞进行测试（＃4）ACH是否增强 Pulvinar/LP细胞对皮质输入的反应。共同这些实验将为未来的生理和/或胆碱能影响选择性注意的行为研究。