Event Abstract Back to Event Noradrenaline and dopamine neurons integrate reward value and effort cost: a direct electrophysiological comparison in behaving monkeys Chiara Varazzani1, 2*, Aurore San-Galli1 and Sebatien Bouret1 1 ICM - Brain & Spine Institute, France 2 Université Paris Descartes-Sorbonne, France Neuromodulation is essential for numerous aspects of behavior, but the specific contribution of each neuromodulator to motivation remains unclear. Here, we take advantage of a dual effect of effort: the perspective of a physical effort reduces the action value as it represents a cost, but it also boosts the mobilization of physiological energy necessary to perform the action. We hypothesize that these 2 aspects differentially involve dopamine (DA) and noradrenaline (NA). We record single unit activity from 60 NA neurons from locus coeruleus (LC) and 47 DA neurons from substantia nigra pars compacta (SNc) of two rhesus macaques who must produce a given effort (3 force levels) in order to obtain a given reward (3 reward sizes). Force level and reward size are visually cued. Abandon rates increase as reward is lower and as effort is higher, indicating that reward value is discounted by the amount of effort required to obtain it. Both NA and DA neurons show a significant increase (p<.01) in firing rates 100-400 ms after cue onset (DA: n=38/47, 83%; NA: n=50/60, 85%) and -100-400 ms around effort onset (DA: n=34/47, 74%; NA: n=47/60, 80%). Cue-response is positively modulated by expected reward in both populations (DA: 24%, n=11/47, NA: 20%, n=12/60. Population-level analyses reveal a correlation between action value and cue-response in DA neurons (r=.15, p<.01), but not in NA neurons. Conversely, during the action itself, we found that response magnitudes of NA neurons positively correlate with the amount of exerted force (r=.17, p<.01) and with pupil dilation (r=.13, p<.01), while DA neurons do not. We conclude that NA and DA neurons share many similarities in reward and effort encoding, but the extent to which our experimental factors affect such activities differs: DA neurons are more sensitive to reward and action value, whereas NA neurons are more sensitive to effort. Keywords: Dopamine, Electrophysiology, Motivation, noradrenaline, effort, non-human primates Conference: XII International Conference on Cognitive Neuroscience (ICON-XII), Brisbane, Queensland, Australia, 27 Jul - 31 Jul, 2014. Presentation Type: Poster Topic: Cognition and Executive Processes Citation: Varazzani C, San-Galli A and Bouret S (2015). Noradrenaline and dopamine neurons integrate reward value and effort cost: a direct electrophysiological comparison in behaving monkeys. Conference Abstract: XII International Conference on Cognitive Neuroscience (ICON-XII). doi: 10.3389/conf.fnhum.2015.217.00382 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 19 Feb 2015; Published Online: 24 Apr 2015. * Correspondence: Mrs. Chiara Varazzani, ICM - Brain & Spine Institute, Paris, France, chiaravara@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Chiara Varazzani Aurore San-Galli Sebatien Bouret Google Chiara Varazzani Aurore San-Galli Sebatien Bouret Google Scholar Chiara Varazzani Aurore San-Galli Sebatien Bouret PubMed Chiara Varazzani Aurore San-Galli Sebatien Bouret Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.