Loss of the trpc4 gene is associated with a reduction in cocaine self-administration and reduced spontaneous ventral tegmental area dopamine neuronal activity, without deficits in learning for natural rewards.
Klipec WD, Burrow KR, O'Neill C, Cao JL, Lawyer CR, Ostertag E, Fowler M, Bachtell RK, Illig KR, Cooper DC. Behav Brain Res. 2016 Jun 1; 306:117-27. Epub 2016 Mar 14.