Cellular Composition of the Preoptic Area Regulating Sleep, Parental, and Sexual Behavior.

Yousuke Tsuneoka,Hiromasa Funato

doi:10.3389/fnins.2021.649159

Yousuke Tsuneoka, Hiromasa Funato

Open Access

https://doi.org/10.3389/fnins.2021.649159

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Abstract

The preoptic area (POA) has long been recognized as a sleep center, first proposed by von Economo. The POA, especially the medial POA (MPOA), is also involved in the regulation of various innate functions such as sexual and parental behaviors. Consistent with its many roles, the MPOA is composed of subregions that are identified by different gene and protein expressions. This review addresses the current understanding of the molecular and cellular architecture of POA neurons in relation to sleep and reproductive behavior. Optogenetic and pharmacogenetic studies have revealed a diverse group of neurons within the POA that exhibit different neural activity patterns depending on vigilance states and whose activity can enhance or suppress wake, non-rapid eye movement (NREM) sleep, or rapid eye movement (REM) sleep. These sleep-regulating neurons are not restricted to the ventrolateral POA (VLPO) region but are widespread in the lateral MPOA and LPOA as well. Neurons expressing galanin also express gonadal steroid receptors and regulate motivational aspects of reproductive behaviors. Moxd1, a novel marker of sexually dimorphic nuclei (SDN), visualizes the SDN of the POA (SDN-POA). The role of the POA in sleep and other innate behaviors has been addressed separately; more integrated observation will be necessary to obtain physiologically relevant insight that penetrates the different dimensions of animal behavior.

Highlights

The preoptic area (POA), the most anterior part of the hypothalamus, is a brain region that has a complex structure consisting of different groups of neurons that control various functions and behaviors essential for the survival of individuals and species
We have recently proposed subdividing the medial POA (MPOA) apart from the established nuclei medial preoptic nucleus (MPN), PD, and ventrolateral POA (VLPO) into four regions, namely, the dorsomedial part of the MPOA, the central part of the MPOA, the ventral
rapid eye movement (REM) sleep restriction induced Fos immunoreactivity in glutamic acid decarboxylase (GAD)-positive neurons in the rat POA and median preoptic nucleus (MnPO) (Gvilia et al, 2006), consistent with REM sleep-specific neurons in the POA (Takahashi et al, 2009). These findings indicate that the POA contains neurons that are active in different aspects of sleep regulation

Summary

Introduction

The preoptic area (POA), the most anterior part of the hypothalamus, is a brain region that has a complex structure consisting of different groups of neurons that control various functions and behaviors essential for the survival of individuals and species. The POA, especially the medial POA (MPOA), plays a crucial role in the regulation of sleep and reproduction-associated behavior, such as parenting and male mating (Tsuneoka et al, 2013; Hull and Dominguez, 2015; Tan et al, 2016; Chung et al, 2017; Kohl et al, 2018). Neurons expressing the neuropeptide galanin, which are involved in the regulation of sleep/wakefulness and reproductive behavior, are abundant in the MPOA but not in the LPOA (Figures 1, 2).

Results

Conclusion