To further examine the relationship between rapid dopamine release and NAc phasic cell firing, linear regression analyses were completed that correlated signal-to-baseline (S:B) ratios for peak [DA]s versus S:B ratios for peak changes in NAc cell firing across cell types. For neurons that displayed increases in firing rate relative to the response (types PR and RFe), a significant positive linear regression was observed between S:B dopamine concentration and S:B cell firing (F1,15 = 6.326, p ≤ 0.05, r2 = 0.30, Figure 5A). Conversely, a significant negative correlation was observed for neurons displaying inhibitions in cell firing relative to the response (type RFi neurons). That is, increases in S:B dopamine levels were significantly correlated with decreases in S:B cell firing of type RFi cells (F1,5 = 36.41, p ≤ 0.01, r2 = 0.88, Figure 5B).
