Figure 3.
Dopamine release during the tastant infusion and during self-administration with coincident tastant infusion. (A) Diagram of cocaine-conditioning regimen. (B,C) Dopamine release during a single cocaine-paired taste cue ‘probe’ trial prior to self-administration (B) and relative to a single lever press for cocaine (C). Two-dimensional color representation of cyclic voltammetric data collected for 20 s around a single tastant infusion (B) and a single lever press (C). The ordinate is the applied voltage (Eapp) and the abscissa is time (s). Changes in current at the carbon-fiber electrode are indicated in color. Differential DA concentrations determined via principal component analysis are plotted in D and E. (F) Infusion of the cocaine-paired tastant elevated dopamine concentration across all animals (mean ± s.e.m.). (G) Dopamine release events were also observed immediately following the lever press. Asterisks indicate significant increases in dopamine concentration compared to baseline.