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bioRxiv · 10.1101/2022.03.30.486380

Incertohypothalamic A13 dopaminergic neurons are involved in fine forelimb movements but not reward

Abstract

Tyrosine hydroxylase (TH)-containing neurons of the dopamine (DA) cell group A13 are well-positioned to impact known dopamine-related functions since their descending projections innervate target regions that regulate vigilance, sensorimotor integration and execution. Despite this known connectivity little is known regarding the functionality of A13-DA circuits. Using TH-specific loss-of-function methodology and techniques to monitor population activity in transgenic rats in vivo we investigated the contribution of A13-DA neurons in reward and movement-related actions. Our work demonstrates a role for A13-DA neurons in grasping and handling of objects that is independent from reward. A13-DA neurons respond strongly when animals grab and manipulate food items while their inactivation or degeneration prevents animals from successfully doing so - a deficit partially attributed to a reduction in grip strength. In contrast, there was no relation between A13-DA activity and food-seeking behavior when animals were tested on a reward-based task that did not include a reaching/grasping response. Moreover, motivation for food was unaffected as goal-directed behavior for food items was in general intact following A13 neuronal inactivation/degeneration. These results demonstrate a functional role for A13-DA neurons in prehensile actions that are uncoupled from reward and as such position A13-DA neurons into the functional framework regarding centrally-located DA populations and their ability to coordinate movement.

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BibTeXRIS

Garau, C., Hayes, J., Chiacchierini, G., McCutcheon, J. E., Apergis-Schoute, J.. 2022-03-31. Incertohypothalamic A13 dopaminergic neurons are involved in fine forelimb movements but not reward. https://doi.org/10.1101/2022.03.30.486380

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