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Papers of the Week

Papers: 13 Feb 2021 - 19 Feb 2021

Animal Studies

2021 Feb 16



A spinoparabrachial circuit defined by Tacr1 expression drives pain.


Barik A, Sathyamurthy A, Thompson JH, Seltzer M, Levine AJ, Chesler A T
Elife. 2021 Feb 16; 10.
PMID: 33591273.


Painful stimuli evoke a mixture of sensations, negative emotions and behaviors. These myriad effects are thought to be produced by parallel ascending circuits working in combination. Here we describe a pathway from spinal cord to brain for ongoing pain. Activation of a subset of spinal neurons expressing Tacr1 evokes a full repertoire of somatotopically-directed pain-related behaviors in the absence of noxious input. Tacr1 projection neurons (expressing NKR1) target a tiny cluster of neurons in the superior lateral parabrachial nucleus (PBN-SL). We showed that these neurons, which also express Tacr1 (PBN-SL), are responsive to sustained but not acute noxious stimuli. Activation of PBN-SL neurons alone did not trigger pain responses but instead served to dramatically heighten nocifensive behaviors and suppress itch. Remarkably, mice with silenced PBN-SL neurons ignored long-lasting noxious stimuli. Together, these data reveal new details about this spinoparabrachial pathway and its key role in the sensation of ongoing pain.