Phasic dopamine release in the rat nucleus accumbens predicts approach and avoidance performance

Abstract

Dopamine (DA) is critical for reward processing, but significantly less is known about its role in punishment avoidance. Using a combined approach-avoidance task, we measured phasic DA release in the nucleus accumbens (NAc) of rats during presentation of cues that predicted reward, punishment or neutral outcomes and investigated individual differences based on avoidance performance. Here we show that DA release within a single microenvironment is higher for reward and avoidance cues compared with neutral cues and positively correlated with poor avoidance behaviour. We found that DA release delineates trial-type during sessions with good avoidance but is non-selective during poor avoidance, with high release correlating with poor performance. These data demonstrate that phasic DA is released during cued approach and avoidance within the same microenvironment and abnormal processing of value signals is correlated with poor performance.

Endocannabinoid Regulation of Reward and Reinforcement through Interaction with Dopamine and Endogenous Opioid Signaling

“…A wide body of FSCV data similarly supports a role for reward-evoked striatal DA release as a prediction error signal. In support of this, unexpected reward delivery or presentation of reward-predictive cues results in phasic DA release (Brown et al, 2011;Cheer et al, 2007;Roitman, 2004;Sunsay and Rebec, 2008), and omission of an expected reward or presentation of an aversive stimulus results in decreased extracellular DA in the ventral striatum (Gentry et al, 2016;Oleson et al, 2012;Roitman et al, 2008).…”

Phasic Dopamine Signals in the Nucleus Accumbens that Cause Active Avoidance Require Endocannabinoid Mobilization in the Midbrain

“…Prior to escape, the WS is theorized to convey an impending aversive stimulus and DA release is reduced [6, 12, 43, 44]. The initial conditioned fear response is a species-specific defensive behavior (freezing in rodents), that interferes with avoidance [45].…”

Extracellular ATP Regulates the Vesicular Pore Opening in Chromaffin Cells and Increases the Fraction Released During Individual Exocytosis Events

“…Many in vivo studies from recent years use FSCV to obtain approximately 10 voltammograms per second. 138,146,147 Although altering the scan rate can be useful, it should also be noted that rapid changes in potential can cause interference in the measurement. This is due to the capacitive properties of the electrode-solution interface as discussed previously (4.1.2…”

“…dopamine, the intricate reward system of the brain has been studied. 146,147 Although transmitter release is important, resetting of the signalling pathways by removing extracellular transmitters is equally important. The question of transmitter uptake has also been addressed with CV.…”