An Inhibitory Medial Preoptic Circuit Mediates Innate Exploration.

Jia Ryoo,Daesoo Kim,Seahyung Park

doi:10.3389/fnins.2021.716147

Jia Ryoo, Daesoo Kim + Show 1 more

Open Access

https://doi.org/10.3389/fnins.2021.716147

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Abstract

Animals have an innate motivation to explore objects and environments with unknown values. To this end, they need to activate neural pathways that enable exploration. Here, we reveal that photostimulation of a subset of medial preoptic area (MPA) neurons expressing the vesicular-GABA transporter gene (vgat+) and sending axonal projections to the ventrolateral periaqueductal gray (vPAG) increases exploration in a chamber but causes no place preference when tested there without photostimulation. Photoinhibition of MPAvgat–vPAG projections leads to no emotional changes as measured by normal activity in an open field assay. Electrophysiological recordings revealed that most GABAergic vPAG neurons are inhibited by MPAvgat neurons. In contrast to a previous report that suggested that MPAvgat–vPAG neurons may impart positive valence to induce place preference, our results suggest that these neurons can increase innate exploration.

Highlights

In nature, animals explore the environment for their survival
To investigate if GABAergic neurons in the medial preoptic area (MPA) were associated with exploration behavior, we first performed optogenetic experiments (Zhang et al, 2006)
These results suggest that photostimulation of MPAvgat neurons maintains the pattern of locomotion seen during explorative behavior

Summary

INTRODUCTION

Animals explore the environment for their survival. Such exploration is required for finding food, prey, monitoring for predators, and investigating males, females, and offspring. The medial preoptic area (MPA) is part of the anterior hypothalamus and has been implicated in playing a role in many types of innately motivated behavior, such as hunting (Park et al, 2018), anxiety (Zhang et al, 2021), reproductive (Wei et al, 2018; McHenry et al, 2017), and parental behavior (Wu et al, 2014; Kohl et al, 2018; Li et al, 2019; Zhang et al, 2021) Such studies have shown to a degree the capability of the MPA to increase extrinsic exploration, due to alterations in underlying homeostatic drives or reproductive drives, the potential role of the MPA in modulating intrinsic exploration has received little attention. To this end, we employed optogenetics to modulate vgat neurons of the MPA and validate if such modulations alter intrinsic exploration

MATERIALS AND METHODS

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DISCUSSION

ETHICS STATEMENT