A new mouse study published in the journal Function bolsters the hypothesis that midbrain dopamine might encode a reward signal useful for learning. Dopamine is a chemical messenger that enables the transmission of signals in the brain.
Dopamine is produced in several areas of the brain including the midbrain. Evidence also suggests the release of dopamine neurons in the midbrain area signals reward prediction error – which means the response to the reward disappears when the reward is predicted or is nonexistent or less than predicted.
This drives the ability of neurons to modify the strength of their connections in the striatum (area of the brain responsible for decision-making and motor control) underlying learning. The increase of striatal dopamine accompanying an unexpected reward activates dopamine type 1 receptors. Although more studies are needed, these early results seem to indicate the likeliness that dopamine signals in the striatum might underlie important aspects of goal-directed reward-based learning. “In conclusion, remarkable progress has been made linking striatal dopamine signals to reward learning, but much remains to be learned,” researchers wrote in their findings. (Newswise/FK)