Your first taste of ice cream probably excited cells in your brain called dopamine neurons. Their activity increases during rewarding experiences but also during novel experiences. Are novel experiences rewarding? Or do different dopamine neurons deal with reward and novelty? Researchers looked for answers in mice. Dopamine neurons (green) extend into a brain region called the striatum, pictured here in slices from front to back (left to right). Tweaked so that more activity meant more green fluorescence, the team watched neurons originating from two different brain regions pervading striatum slices (top set and bottom set). When mice were exposed to new smells only one set (bottom) showed increased activity, seen at the back of the striatum. Some smells came with a reward, and when mice twigged this, the other set (top) showed increased activity, now at the bottom of the striatum. The verdict: reward and novelty trigger different dopamine neurons.
Written by Lux Fatimathas
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