Early-life adversity facilitates acquisition of cocaine self-administration and induces persistent anhedonia

Publication date: February 2018Source: Neurobiology of Stress, Volume 8Author(s): Jessica L. Bolton, Christina M. Ruiz, Neggy Rismanchi, Gissell A. Sanchez, Erik Castillo, Jeff Huang, Christopher Cross, Tallie Z. Baram, Stephen V. MahlerAbstractEarly-life adversity increases the risk for emotional disorders such as depression and schizophrenia. Anhedonia, thought to be a core feature of these disorders, is provoked by our naturalistic rodent model of childhood adversity (i.e., rearing pups for one week in cages with limited bedding and nesting, LBN). Drug use and addiction are highly comorbid with psychiatric disorders featuring anhedonia, yet effects of LBN on drug-seeking behavior and the reward and stress-related circuits that underlie it remain unknown. Here we examined the effects of LBN on cocaine intake and seeking, using a battery of behavioral tests measuring distinct aspects of cocaine reward, and for comparison, chocolate intake. We also examined activation of neurons within the pleasure/reward and stress circuits following cocaine in LBN and control rats. Early-life adversity reduced spontaneous intake of palatable chocolate, extending prior reports of sucrose and social-play anhedonia. In a within-session cocaine behavioral economic test, LBN rats self-administered lower dosages of cocaine under low-effort conditions, consistent with a reduced hedonic set-point for cocaine, and potentially anhedonia. In contrast, cocaine demand elasticity was not consistently aff...
Source: Neurobiology of Stress - Category: Neuroscience Source Type: research