Assessment of total TH protein expression using synaptosomal preparation. TH expression levels were significantly greater in aSI compared to aGH rats suggesting greater dopamine synthesis. (inset) Illustration of a Western blot image showing higher TH expression in aSI rats, with similar actin levels in aGH and aSI rats as the control. Tyrosine hydroxylase, TH; Group housed, aGH, blue, n = 4; Socially isolated, aSI, red, n = 4.