Heterogeneous output pathways link the anterior pretectal nucleus with the zona Incerta and the thalamus in rat
Heterogeneous output pathways link the anterior pretectal nucleus with the zona Incerta and the thalamus in rat
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DOI：
10.1002/cne.21545
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发表时间：
2008-01-01
影响因子：
2.5
通讯作者：
Acsady, Laszlo
中科院分区：
文献类型：
--
作者：
Giber, Kristof;Slezia, Andrea;Acsady, Laszlo
前额叶前核（APT）和中间带（ZI）是间脑核，在高阶丘脑接力中选择性地施加强烈的抑制影响。众所周知，APT也投射到ZI和丘脑，但尚未描述APT-ZI投射的解剖细节。本研究采用逆行和逆行示踪，结合包埋前后免疫细胞化学染色和原位杂交技术，对APT- zi -丘脑网络中APT的输出通路进行了研究。绝大多数APT纤维选择性地支配小蛋白阳性的ZI腹侧部分，其中包含轴突突出到高阶丘脑核的ZI神经元。APT-ZI通路由γ -氨基丁酸（GABA）阴性和GABA阳性组分组成；ZI中38.2%的末端含有GABA， APT中8.6%的突起体中谷氨酸脱羧酶67 (GAD67) mRNA阳性。副白蛋白免疫染色与逆行示踪相结合显示，投射到ZI的APT细胞群中存在着小白蛋白强阳性和弱阳性以及小白蛋白阴性的神经元。在投射到丘脑的APT细胞中也发现了类似的异质性。高阶丘脑核及其地形匹配的ZI区域的双逆行示踪几乎没有发现APT神经元具有双投射。我们的数据表明，ZI和高阶丘脑接力都是由不同的、生理上异质的APT神经元支配的。这些不同的传出途径可能通过突出的APT细胞的丰富的循环侧枝相互作用。因此，强大的、gabaergy的丘脑APT和ZI输出显然是通过双重兴奋性和抑制性APT-ZI连接以协同方式共调节的。
The anterior pretectal nucleus (APT) and the zona incerta (ZI) are diencephalic nuclei that exert a strong inhibitory influence selectively in higher order thalamic relays. The APT is also known to project to the ZI as well as the thalamus, but anatomical details of the APT-ZI projection have not been described. In the present study, the efferent pathways of the APT were examined in the APT-ZI-thalamus network by using anterograde and retrograde tracing in combination with pre- and postembedding immunocytochemical stainings and in situ hybridization. The vast majority of APT fibers selectively innervated the parvalbumin-positive, ventral part of the ZI, which contains ZI neurons with axons projecting to higher order thalamic nuclei. The APT-ZI pathway consisted of both gamma-aminobutyric acid (GABA)negative and GABA-positive components; 38.2% of the terminals in the ZI contained GABA, and 8.6% of the projecting somata in the APT were glutamic acid decarboxylase 67 (GAD67) mRNA positive. The combination of paravalbumin immunostaining with retrograde tracing showed that strongly and weakly parvalbumin-positive as well as parvalbumin-negative neurons were all among the population of APT cells projecting to the ZI. Similar heterogeneity was found among the APT cells projecting to the thalamus. Double retrograde tracing from higher order thalamic nuclei and their topographically matched ZI regions revealed hardly any APT neuron with dual projections. Our data suggest that both ZI and the higher order thalamic relays are innervated by distinct, physiologically heterogeneous APT neurons. These various efferent pathways probably interact via the rich recurrent collaterals of the projecting APT cells. Therefore, the powerful, GABAergic APT and ZI outputs to the thalamus are apparently co-modulated in a synergistic manner via dual excitatory and inhibitory APT-ZI connections.