Involvement of A13 dopaminergic neurons in prehensile movements but not reward in the rat

Celia Garau; Jessica Hayes; Giulia Chiacchierini; James E McCutcheon; John Apergis-Schoute

doi:10.1016/j.cub.2023.09.044

Involvement of A13 dopaminergic neurons in prehensile movements but not reward in the rat

Curr Biol. 2023 Nov 20;33(22):4786-4797.e4. doi: 10.1016/j.cub.2023.09.044. Epub 2023 Oct 9.

Authors

Celia Garau¹, Jessica Hayes², Giulia Chiacchierini³, James E McCutcheon⁴, John Apergis-Schoute⁵

Affiliations

¹ Department of Neuroscience, Psychology & Behaviour, University of Leicester, University Road, Leicester LE1 9HN, UK. Electronic address: celiagarau@gmail.com.
² Department of Neuroscience, Psychology & Behaviour, University of Leicester, University Road, Leicester LE1 9HN, UK.
³ Department of Neuroscience, Psychology & Behaviour, University of Leicester, University Road, Leicester LE1 9HN, UK; Department of Physiology and Pharmacology, La Sapienza University of Rome, 00185 Rome, Italy; Laboratory of Neuropsychopharmacology, Santa Lucia Foundation, 00143 Rome, Italy.
⁴ Department of Neuroscience, Psychology & Behaviour, University of Leicester, University Road, Leicester LE1 9HN, UK; Department of Psychology, UiT The Arctic University of Norway, Huginbakken 32, 9037 Tromsø, Norway.
⁵ Department of Neuroscience, Psychology & Behaviour, University of Leicester, University Road, Leicester LE1 9HN, UK; Department of Biological and Experimental Psychology, Queen Mary University of London, London E1 4NS, UK. Electronic address: j.apergis-schoute@qmul.ac.uk.

PMID: 37816347
DOI: 10.1016/j.cub.2023.09.044

Abstract

Tyrosine hydroxylase (TH)-containing neurons of the dopamine (DA) cell group A13 are well positioned to impact known DA-related functions as their descending projections innervate target regions that regulate vigilance, sensory integration, and motor execution. Despite this 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 but not reward. A13-DA neurons responded strongly when animals grab and manipulate food items, whereas their inactivation or degeneration prevented animals from successfully doing so-a deficit partially attributed to a reduction in grip strength. By 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. Motivation for food was unaffected, as goal-directed behavior for food items was in general intact following A13 neuronal inactivation/degeneration. An anatomical investigation confirmed that A13-DA neurons project to the superior colliculus (SC) and also demonstrated a novel A13-DA projection to the reticular formation (RF). These results establish a functional role for A13-DA neurons in prehensile actions that are uncoupled from the motivational factors that contribute to the initiation of forelimb movements and help position A13-DA circuits into the functional framework regarding centrally located DA populations and their ability to coordinate movement.

Keywords: A13; dopamine; grasping; neural circuits; reticular formation; skilled forelimb movements; superior colliculus; zona incerta.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Dopaminergic Neurons*
Rats
Reticular Formation*
Reward