Showing the way. Here the authors challenged the commonly accepted hypothesis that neurons in dorsal striatum regulated motor behavior with GO! or STOP! signals. This simplicity seemed in contradiction with the richness of sensory inputs striatum received. They found activity of neurons turned on and off one after the other the entire time the animal accomplished a motor task. Striatal activity was uninterrupted, distributed over a neuronal population which seemingly monitored continuously body movements. (by Ingrid Bureau)
The authors: C. Sales-Carbonell, W. Taouali, L. Khalki, T. Moreau, P.E. Rueda-Orozco and D. Robbe.
Scientific abstract: A popular hypothesis is that the dorsal striatum generates discrete “traffic light” signals that initiate, maintain, and terminate the execution of learned actions. Alternatively, the striatum may continuously monitor the dynamics of movements associated with action execution by processing inputs from somatosensory and motor cortices. Here, we recorded the activity of striatal neurons in mice performing a run-and-stop task and characterized the diversity of firing rate modulations relative to run performance (tuning curves) across neurons. We found that the tuning curves could not be statistically clustered in discrete functional groups (start or stop neurons). Rather, their shape varied continuously according to the movement dynamics of the task. Moreover, striatal spiking activity correlated with running speed on a run-by-run basis and was modulated by task-related non-locomotor movements, such as licking. We hypothesize that such moment-to-moment movement monitoring by the dorsal striatum contributes to the learning of adaptive actions and/or updating their kinematics.
Published in Current Biology, October 2018
More work from this group here