Regulation of nociception by long-term potentiation of… : PAIN
]), whose inputs strongly suppress the activities of PNs. This study investigated how PVNs in the IC modulate pain-related behaviors using optogenetics. To evaluate the effect of PVN activation on pain-related behavior, we applied nociceptive heat stimulation to the whisker pads of PV-Cre rats that received an injection of adeno-associated virus-Flex-channelrhodopsin-2-mCherry into the IC. Exposure to nociceptive heat stimulation significantly increased the amount of pain-related escape behavior, and PVN activation by optogenetics did not significantly decrease pain-related behavior. We next examined the possibility that long-term potentiation (LTP) of PVN→PN synapses suppresses pain-related behaviors. We recorded light-evoked inhibitory postsynaptic currents (IPSCs) from PNs in the IC slice preparation to examine whether optogenetic activation of PVNs can induce LTP. Repetitive optogenetic stimulation (ROS) of PVNs in a manner analogous to theta burst stimulation increased the amplitu
