Table2
  • Distribution of neuronal responses during cocaine and heroin self-administration trials during cocaine-first, heroin-second sessions from 110 mPFC and 111 NAc neurons. A, Data from mPFC; the horizontal direction displays different types of responses for cocaine self-administration. Vertical direction shows the responses for heroin self-administration. Fifty-two (47.3% of 110) neurons exhibited no response to either the cocaine or heroin sessions. A single neuron may have more than one attribute by exhibiting more than one response in different categories. The 58 (of 110) neurons that did respond exhibited 75 neuron response cases across the different categories. Of these there were only 14 instances (18.7% of 75) when similar responses to both cocaine and heroin were observed. The dark shaded blocks in the diagonal show the neurons that share the same response during both cocaine and heroin self-administration segments. Light shaded blocks represent the neuron-response cases having different responses during cocaine and heroin self-administration. Sixty-one neuron response cases (81.3% of 75) responded differently during cocaine and heroin self-administration phases. B, Comparison of neuronal responses of the NAc during cocaine and heroin self-administration as in A. Only 25% of neurons exhibited the same response to both cocaine and heroin whereas 75% of neurons responded differently to cocaine and heroin self-administration.