title: Unilateral medial frontal cortex lesions cause a cognitive decision-making deficit in rats.
abstract: The medial frontal cortex (MFC) is critical for cost-benefit decision-making. Generally, cognitive and reward-based behaviour in rodents is not thought to be lateralised within the brain. In this study, however, we demonstrate that rats with unilateral MFC lesions show a profound change in decision-making on an effort-based decision-making task. Furthermore, unilateral MFC lesions have a greater effect when the rat has to choose to put in more effort for a higher reward when it is on the contralateral side of space to the lesion. Importantly, this could not be explained by motor impairments as these animals did not show a turning bias in separate experiments. In contrast, rats with unilateral dopaminergic midbrain lesions did exhibit a motoric turning bias, but were unimpaired on the effort-based decision-making task. This rare example of a cognitive deficit caused by a unilateral cortical lesion in the rat brain indicates that the MFC may have a specialised and lateralised role in evaluating the costs and benefits of actions directed to specific spatial locations.
authors.affiliation: Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, 1470 Madison Avenue, New York, NY, 10029, USA; Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford, OX1 3UD, UK.
authors.forename: Paula L
authors.initials: PL
authors.lastname: Croxson
authors.forename: Mark E
authors.initials: ME
authors.lastname: Walton
authors.forename: Erie D
authors.initials: ED
authors.lastname: Boorman
authors.forename: Matthew F S
authors.initials: MF
authors.lastname: Rushworth
authors.forename: David M
authors.initials: DM
authors.lastname: Bannerman
mesh_terms: D000818:Animals; D003072:Cognition Disorders / Q000503:physiopathology*; D003657:Decision Making / Q000502:physiology*; D004298:Dopamine / Q000378:metabolism; D005625:Frontal Lobe / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology*; D007839:Functional Laterality / Q000502:physiology*; D008297:Male; D008636:Mesencephalon / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology; D009043:Motor Activity / Q000502:physiology; D009483:Neuropsychological Tests; D016627:Oxidopamine / Q000633:toxicity; D010784:Photomicrography; D017378:Quinolinic Acid / Q000633:toxicity; D051381:Rats; D012201:Reward
chemical_list: D016627:Oxidopamine; D017378:Quinolinic Acid; D004298:Dopamine
keywords: T-maze; decision; lesion; neglect; rat