PubMed: Δ<sup>9</sup> -Tetrahydrocannabinol self-administration induces cell type-specific adaptations in the nucleus accumbens core
Addict Biol. 2023 Aug;28(8):e13286. doi: 10.1111/adb.13286.
Drugs of abuse induce cell type-specific adaptations in D1- and D2-medium spiny neurons (MSNs) in the nucleus accumbens core (NAcore) that can bias signalling towards D1-MSNs and enhance relapse vulnerability. Whether Δ9 -tetrahydrocannabinol (THC) use initiates similar neuroadaptations is unknown. D1- and D2-Cre transgenic rats were transfected with Cre-dependent reporters and trained to self-administer THC + cannabidiol (THC + CBD). After extinction training spine morphology, glutamate transmission, CB1R function and cFOS expression were quantified. We found that extinction from THC + CBD induced a loss of large spine heads in D1- but not D2-MSNs and commensurate reductions in glutamate synaptic transmission. Also, presynaptic CB1R function was impaired selectively at glutamatergic synapses on D1-MSNs, which augmented the capacity to potentiate glutamate transmission. Using cFOS expression as an activity marker, we found no change after extinction but increased cFOS expression in D1-MSNs after cue-induced drug seeking. Contrasting D1-MSNs, CB1R function and glutamate synaptic transmission on D2-MSN synapses were unaffected by THC + CBD use. However, cFOS expression was decreased in D2-MSNs of THC + CBD-extinguished rats and was restored after drug seeking. Thus, CB1R adaptations in D1-MSNs partially predicted neuronal activity changes, posing pathway specific modulation of eCB signalling in D1-MSNs as a potential treatment avenue for cannabis use disorder (CUD).
https://pubmed.ncbi.nlm.nih.gov/37500492/?utm_source=Chrome&utm_medium=rss&utm_campaign=pubmed-2&utm_content=1NqsX9BbHlDygQ8TcgAlJilHgPpiuKQtyIr–a3-xbLzPoB9xM&fc=20220928170152&ff=20230728135633&v=2.17.9.post6+86293ac July 27, 2023 10:00 am