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Papers of the Week

Papers: 4 Jun 2022 - 10 Jun 2022

2022 Jun 06


Neurexin 3α in the central amygdala has a role orofacial varicella zoster pain.


Kramer PR, Umorin M, Hornung R, Kinchington PR
Neuroscience. 2022 Jun 06.
PMID: 35679996.


Varicella zoster virus (VZV) is responsible for chronic pain. VZV injection has similarities to herpes zoster "shingles" pain in humans. In this study orofacial pain was induced by injecting male rats with the human varicella zoster virus (VZV). The amygdala and parabrachial have been implicated to control affective/motivational orofacial pain. Recently our lab reported neurexin 3α (Nrxn3α) is expressed in the central amygdala and parabrachial. GABAergic neurons descend from the central amygdala to the lateral parabrachial region and Nrxn3α is important for presynaptic GABA release. Thus, we hypothesized that lateral parabrachial neuronal activity and orofacial pain are controlled by Nrxn3α within the central amygdala. To test the hypothesis Nrxn3 expression was knocked down (i.e., using shRNA) in the central amygdala and GABA release and neuronal activity were quantitated in the parabrachial concomitant with measurement of the VZV induced pain response. Results revealed that attenuating Nrxn3 expression within the amygdala reduces GABA release in the parabrachial and increases neuronal activity within the lateral parabrachial region. Attenuating Nrxn3 expression also increases VZV associated orofacial pain. Activating GABAergic neurons within the central amygdala with opsins increase GABA release in the parabrachial and reduced the pain response after Nrxn3 shRNA treatment. These results are consistent with the idea that Nrxn3 within the central amygdala controls VZV associated pain by regulating GABA release in the lateral parabrachial that then controls the activity of ascending pain neurons.