AUTHOR=Chen Yuh-Tarng , Arano Rachel , Guo Jun , Saleem Uzair , Li Ying , Xu Wei TITLE=Inhibitory hippocampus-medial septum projection controls locomotion and exploratory behavior JOURNAL=Frontiers in Synaptic Neuroscience VOLUME=15 YEAR=2023 URL=https://www.frontiersin.org/journals/synaptic-neuroscience/articles/10.3389/fnsyn.2023.1042858 DOI=10.3389/fnsyn.2023.1042858 ISSN=1663-3563 ABSTRACT=

Although the hippocampus is generally considered a cognitive center for spatial representation, learning, and memory, increasing evidence supports its roles in regulating locomotion. However, the neuronal mechanisms of the hippocampal regulation of locomotion and exploratory behavior remain unclear. In this study, we found that the inhibitory hippocampal synaptic projection to the medial septum (MS) bi-directionally controls the locomotor speed of mice. The activation of the MS-projecting interneurons in the hippocampus or the activation of the hippocampus-originated inhibitory synaptic terminals in the MS decreased locomotion and exploratory behavior. On the other hand, the inhibition of the hippocampus-originated inhibitory synaptic terminals in the MS increased locomotion. Unlike the septal projecting interneurons, the activation of the hippocampal interneurons projecting to the retrosplenial cortex did not change animal locomotion. Therefore, this study reveals a specific long-range inhibitory synaptic output from the hippocampus to the medial septum in the regulation of animal locomotion.