Lin C S, Nicolelis M A, Schneider J S, Chapin J K
Department of Physiology and Biophysics, Hahnemann University, Philadelphia, PA 19102.
Science. 1990 Jun 22;248(4962):1553-6. doi: 10.1126/science.2360049.
Retrograde fluorescent tracers were used to demonstrate a previously unknown but sizable direct gamma-aminobutyric acid (GABA)-containing neuronal pathway from the zona incerta to the neocortex in rats. This incertocortical pathway was found to project bilaterally to the entire neocortex and exhibited a rough corticotopic organization. Many of the zona incerta neurons projecting to the parietal and occipital cortices could also be immunohistochemically stained with antibodies to glutamic acid decarboxylase and GABA. Few of these neurons were immunoreactive to tyrosine hydroxylase antibodies, which identify dopamine-containing neurons. Injections in the frontal and entorhinal cortices labeled many neurons near or within the dopaminergic A13 subdivision of the zona incerta. In addition, the incertocortical system was found to be significantly larger during early postnatal (2 to 3 weeks) development. The projection pattern of this newly discovered pathway resembles that of the monoaminergic and cholinergic systems, arising from the brainstem and forebrain, suggesting possible similarities of function.
逆行荧光示踪剂被用于证明大鼠中一条从前未知但规模可观的、从未定带到新皮层的直接含γ-氨基丁酸（GABA）的神经元通路。发现这条未定带-皮层通路双侧投射至整个新皮层，并呈现出大致的皮层定位组织。许多投射至顶叶和枕叶皮层的未定带神经元也能用谷氨酸脱羧酶和GABA抗体进行免疫组织化学染色。这些神经元中很少对酪氨酸羟化酶抗体呈免疫反应，酪氨酸羟化酶抗体用于识别含多巴胺的神经元。在前额叶和内嗅皮层的注射标记了未定带多巴胺能A13亚区附近或内部的许多神经元。此外，发现这条未定带-皮层系统在出生后早期（2至3周）发育期间显著更大。这条新发现通路的投射模式类似于源自脑干和前脑的单胺能和胆碱能系统，提示可能存在功能上的相似性。
