Vounatsos Maxime V, Gittis Aryn H
Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213.
Center for the Neural Basis of Cognition, Pittsburgh, Pennsylvania 15213.
J Neurosci. 2025 Jan 8;45(2):e1446242024. doi: 10.1523/JNEUROSCI.1446-24.2024.
The external segment of the globus pallidus (GPe) is involved in the modulation of the motor output and limbic components of behavior. The circuitry by which the GPe contributes to limbic components of behavior remains unknown. While many investigations have focused on the local circuitry within the basal ganglia, numerous GPe projections to target regions outside of the basal ganglia including the midbrain, thalamus, and cortex exist and remain largely unexplored. Here, by anatomical and electrophysiological means, we investigate the projections of the GPe to the retrorubral field (RRF), a dopaminergic nucleus in the caudal midbrain, in both male and female mice. We find that the GPe targets both GABAergic and DAergic neurons in the RRF (RRF and RRF). Viral-assisted circuit mapping to trace the cell-type-specific projection patterns of RRF and RRF populations revealed diverging pathways. The connectivity of GPe-recipient RRF neurons followed the traditional medial forebrain bundle path, innervating the ventral striatum and to a lesser extent the dorsal striatum. GPe-recipient RRF neurons, on the other hand, displayed broad projections targeting numerous brain regions involved in limbic function including the parabrachial nucleus, amygdala, and hypothalamus. These contrasting projection profiles reveal multiple nodes by which the GPe is disynaptically connected to the limbic system, representing novel access points for the GPe to modulate limbic components of behavior.
苍白球外侧段(GPe)参与行为的运动输出和边缘系统成分的调节。GPe对行为边缘系统成分起作用的神经回路尚不清楚。虽然许多研究集中在基底神经节内的局部神经回路,但GPe向基底神经节以外的目标区域(包括中脑、丘脑和皮质)有大量投射,且在很大程度上仍未被探索。在这里,我们通过解剖学和电生理学方法,研究了雄性和雌性小鼠中GPe向红核后区(RRF,中脑尾部的一个多巴胺能核)的投射。我们发现GPe靶向RRF中的GABA能神经元和多巴胺能神经元(RRF和RRF)。通过病毒辅助回路映射来追踪RRF和RRF群体的细胞类型特异性投射模式,发现了不同的通路。接受GPe投射的RRF神经元沿着传统的内侧前脑束路径,支配腹侧纹状体,在较小程度上支配背侧纹状体。另一方面,接受GPe投射的RRF神经元表现出广泛的投射,靶向包括臂旁核、杏仁核和下丘脑在内的多个参与边缘系统功能的脑区。这些截然不同的投射模式揭示了GPe与边缘系统双突触连接的多个节点,代表了GPe调节行为边缘系统成分的新切入点。