Perspectives on Behavioural Function of Dopamine in the Nucleus Accumbens

Re: Breadth mint or candy? Feelings of Energy

John Salamone
salamone@psych.psy.uconn.edu

When I speculate about this (i.e., feelings of energy), I sometimes call it "an internal signal of self-efficacy" (originally suggested to me by Jon Horvitz), or "I can do it!" Of course, I do not think this is what anyone normally thinks of when they say "reward". In fact, if some of the advocates of the DA reward hypotheses could simply say "Oh yes, that is exactly what I mean", then the controversy could be over. Wise, in the past, has talked about the role of dopamine in "motivational arousal", and this is not that different from the terms "behavioral activation" or "activational aspects of motivation" which I have used. It is useful to consider that such a role could be played by nucleus accumbens.

***Warning..... This is highly speculative****
My old advisor, Darryl Neill, used to talk about cortical and basal ganglia mechanisms as being involved in the "contemplation" of movement, and of course one could also use the term motor planning. The nucleus accumbens is a part of the circuitry that links prefrontal cortex with pallidal areas and thalamus. In view of the notion that prefrontal cortex is involved in planning and organization of behavior, I wonder if one of the roles of the accumbens is to feed information about the propensity for spending energy (or overcoming constraints) into the prefrontal cortex, and then cortical mechanisms utilize this information in formulating motor plans and response selection strategies. Thus, some of the behavioral effects of accumbens DA depletions represent the result of an alteration of prefrontal function due to a loss of this type of input.

Wed Dec 16