Figure 6.

Functional requirement of lPBN neurons for driving distinct behaviors in response to noxious stimuli

Summary of roles of neurons in different lPBN subnuclei for driving distinct behaviors in responses to noxious stimuli under physiological conditions. As a whole population, NK1R⁺ neurons (green dots), mainly located in the slPBN, are required for driving persistent licking induced by sustained noxious thermal and mechanical stimuli applied to the skin and bone/muscle. dlPBN neurons are required for behavioral thermoregulation (Yahiro et al., 2017), and are also involved in provoking jumping behavior (Chiang et al., 2020). elPBN neurons (mainly expressing CGRP, Tac1, or Oprm1) are required for driving defensive reactions such as freezing and jumping, as well as conditioned fear (Barik et al., 2018; Han et al., 2015; Liu et al., 2022 and this study). Both elPBN and slPBN (and potentially dlPBN) neurons are required for inducing nocifensive and emotional responses after inflammatory irritation, such as hind paw formalin injection or intraperitoneal injection of acetic acid (Deng et al., 2020; Liu et al., 2020; This study).