Dopamine neurons are more heterogeneous than was previously thought, a Nature paper suggests. The finding challenges widely held conceptions about this cell type, which are known to be involved in motor control and reward processing.
Masayuki Matsumoto and Okihide Hikosaka report that in monkeys, two types of dopamine neuron distinctly convey positive and negative motivational signals. The different cell types, located in slightly different brain regions, have specific responses to pleasant and unpleasant stimuli, as well as to the trigger stimuli that have become linked with these events.
The findings contradict the view that dopamine neurons act as a functionally homogeneous group, guiding motor learning by reward-related signals. Here, separate groups of dopamine neurons transmit signals related to 'salience' and 'value.'
Masayuki Matsumoto (National Eye Institute, Bethesda, MD, USA)
Abstract available online.
(C) Nature press release.
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