title: Differential developmental trajectories for CB1 cannabinoid receptor expression in limbic/associative and sensorimotor cortical areas.
abstract: Cannabis use during adolescence is associated with an increased risk for schizophrenia and other disorders. The neuronal basis is unclear, but prefrontal cortical mechanisms have been implicated. Here, we investigated developmental changes in the endocannabinoid system by assessing expression and function of the CB1 cannabinoid receptor in prefrontal and other cortical areas in juvenile (postnatal day 25, P25), adolescent (P40), and adult (P70) rats. Overall, the expression of CB1 receptors in the cortex is highest in juveniles and drops thereafter toward adult levels. However, CB1 receptor expression follows distinct developmental trajectories in different cortical areas. The most pronounced and progressive decrease in CB1 expression was observed in medial prefrontal and other limbic/associative regions. In contrast, major changes in sensorimotor cortices occurred only after P40. We also assessed electrophysiological measures of CB1 receptor function and found that CB1-dependent inhibition of synaptic transmission in the prefrontal cortex follows the same developmental trajectory as observed for receptor expression. Together, these findings indicate that CB1 receptor-mediated signaling decreases during development but is differentially regulated in limbic/associative vs. sensorimotor systems. Therefore, cannabis use during adolescence likely differentially affects limbic/associative and sensorimotor cortical circuits.
authors.affiliation: Department of Cellular and Molecular Pharmacology, Rosalind Franklin University of Medicine and Science, The Chicago Medical School, North Chicago, Illinois 60064, USA.
authors.forename: Lijun
authors.initials: L
authors.lastname: Heng
authors.forename: Joel A
authors.initials: JA
authors.lastname: Beverley
authors.forename: Heinz
authors.initials: H
authors.lastname: Steiner
authors.forename: Kuei Y
authors.initials: KY
authors.lastname: Tseng
mesh_terms: D000367:Age Factors; D000818:Animals; D001245:Association Learning / Q000502:physiology; D005786:Gene Expression Regulation / Q000502:physiology; D008032:Limbic System / Q000378:metabolism*; D008297:Male; D009044:Motor Cortex / Q000378:metabolism*; D017397:Prefrontal Cortex / Q000378:metabolism* / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D043884:Receptor, Cannabinoid, CB1 / Q000096:biosynthesis* / Q000502:physiology; D013003:Somatosensory Cortex / Q000378:metabolism / Q000502:physiology
chemical_list: D043884:Receptor, Cannabinoid, CB1