Tamping Ramping: Algorithmic, Implementational, and Computational Explanations of Phasic Dopamine Signals in the Accumbens

Mode of sucrose delivery alters reward-related phasic dopamine signals in nucleus accumbens

Relationship of Dopamine of the Nucleus Accumbens with Intra-infralimbic Apomorphine Microinjection

  Objective(s): The dopamine level of the nucleus accumbens changes during some stereotyped behaviors. To study dopamine level of the nucleus accumbens in intra infralimbic apomorphine-induced climbing, microdialysis probes were implanted into the nucleus accumbens shell of male Sprague Dawley rats weighting 275–400 g.   Materials and Methods: The rats were divided into two groups (apomorphine ...

Physiological state gates acquisition and expression of mesolimbic reward prediction signals.

Phasic dopamine signaling participates in associative learning by reinforcing associations between outcomes (unconditioned stimulus; US) and their predictors (conditioned stimulus; CS). However, prior work has always engendered these associations with innately rewarding stimuli. Thus, whether dopamine neurons can acquire prediction signals in the absence of appetitive experience and update them...

Dopamine Ramps Are a Consequence of Reward Prediction Errors

Temporal difference learning models of dopamine assert that phasic levels of dopamine encode a reward prediction error. However, this hypothesis has been challenged by recent observations of gradually ramping stratal dopamine levels as a goal is approached. This note describes conditions under which temporal difference learning models predict dopamine ramping. The key idea is representational: ...

Controls of tonic and phasic dopamine transmission in the dorsal and ventral striatum.

Dopamine (DA) release varies within subregions and local environments of the striatum, suggesting that controls intrinsic and extrinsic to the DA fibers and terminals regulate release. While applying fast-scan cyclic voltammetry and using tonic and phasic stimulus trains, we investigated the regulation of DA release in the dorsolateral to ventral striatum. The ratio of phasic-to-tonic-evoked DA...