Mapping brain regions processing colorectal nociception

Extrinsic nerves innervating the colon are important to the regulation and integration of autonomic (i.e. motility) and sensory (i.e. pain) functions. This study aimed to identify the brain circuits into which extrinsic nerves from the distal colon convey nociceptive information in the mouse. Anterograde trans-neuronal tracing with herpes simplex virus 1 expressing EGFP (HSV-H129-EGFP) was used from the colorectum to map the neuronal expression of EGFP in the CNS in a time dependent manner (ANS 2019 poster attached). To identify brain regions engaged by colonic nociceptive stimuli the number of neurons activated by noxious in vivo colorectal distension was compared to that evoked by no distension (2021 Global Connectome poster attached). Male and female mice allowed for sex comparisons in how colorectal pain processing may be differentially processed within central pathways.