Blockade of muscarinic acetylcholine receptors facilitates motivated behaviour and rescues a model of antipsychotic-induced amotivation

Authors

Jonathan M. Hailwood, Behavioural and Clinical Neuroscience Institute
Christopher J. Heath, The Open University
Benjamin U. Phillips, Behavioural and Clinical Neuroscience Institute
Trevor W. Robbins, Behavioural and Clinical Neuroscience Institute
Lisa M. Saksida, Robarts Research Institute
Timothy J. Bussey, Behavioural and Clinical Neuroscience InstituteFollow

Document Type

Article

Publication Date

5-1-2019

Journal

Neuropsychopharmacology

Volume

44

Issue

6

First Page

1068

Last Page

1075

URL with Digital Object Identifier

10.1038/s41386-018-0281-8

Abstract

© 2018, American College of Neuropsychopharmacology. Disruptions to motivated behaviour are a highly prevalent and severe symptom in a number of neuropsychiatric and neurodegenerative disorders. Current treatment options for these disorders have little or no effect upon motivational impairments. We assessed the contribution of muscarinic acetylcholine receptors to motivated behaviour in mice, as a novel pharmacological target for motivational impairments. Touchscreen progressive ratio (PR) performance was facilitated by the nonselective muscarinic receptor antagonist scopolamine as well as the more subtype-selective antagonists biperiden (M1) and tropicamide (M4). However, scopolamine and tropicamide also produced increases in non-specific activity levels, whereas biperiden did not. A series of control tests suggests the effects of the mAChR antagonists were sensitive to changes in reward value and not driven by changes in satiety, motor fatigue, appetite or perseveration. Subsequently, a sub-effective dose of biperiden was able to facilitate the effects of amphetamine upon PR performance, suggesting an ability to enhance dopaminergic function. Both biperiden and scopolamine were also able to reverse a haloperidol-induced deficit in PR performance, however only biperiden was able to rescue the deficit in effort-related choice (ERC) performance. Taken together, these data suggest that the M1 mAChR may be a novel target for the pharmacological enhancement of effort exertion and consequent rescue of motivational impairments. Conversely, M4 receptors may inadvertently modulate effort exertion through regulation of general locomotor activity levels.

Notes

This article is freely available to read from the publisher