The anabolic-androgenic steroid nandrolone decanoate affects the density of dopamine receptors in the male rat brain

In recent years a male group of anabolic‐androgenic steroid misusers has been identified to share socio‐demographic and personality related background factors with misusers of psychotropic substances, as well as being involved in habits of multiple drug use. The present study aimed to assess whether anabolic‐androgenic steroids (AAS) would affect the density of the dopamine receptors in areas implicated in reward and behaviour in the male rat brain. The effects of 2 weeks of treatment with i.m. injections of nandrolone decanoate (15 mg/kg/day) on the expression of the D1‐like and D2‐like receptors were evaluated by autoradiography. Specific binding of D1‐like receptors was significantly down regulated in the caudate putamen, the nucleus accumbens core and shell. D2‐like receptor densities were down regulated in the nucleus accumbens shell, but up regulated in the caudate putamen, the nucleus accumbens core and the ventral tegmental area. These results are compatible with nandrolone induced neuroadaptive alterations in dopamine circuits associated with motor functions and behavioural paradigms known to be affected following AAS misuse.