title: Basal forebrain dynamics during a tactile discrimination task.
abstract: The nucleus basalis (NB) is a cholinergic neuromodulatory structure that projects liberally to the entire cortical mantle and regulates information processing in all cortical layers. Here, we recorded activity from populations of single units in the NB as rats performed a whisker-dependent tactile discrimination task. Over 80% of neurons responded with significant modulation in at least one phase of the task. Such activity started before stimulus onset and continued for seconds after reward delivery. Firing rates monotonically increased with reward magnitude during the task, suggesting that NB neurons are not indicating the absolute deviation from expected reward amounts. Individual neurons also encoded significant amounts of information about stimulus identity. Such robust coding was not present when the same stimuli were delivered to lightly anesthetized animals, suggesting that the NB neurons contain a sensorimotor, rather than purely sensory or motor, representation of the environment. Overall, these results support the hypothesis that neurons in the NB provide a value-laden representation of the sensorimotor state of the animal as it engages in significant behavioral tasks.
authors.affiliation: Department of Neurobiology, Duke University, Durham, North Carolina; Edmond and Lily Safra International Institute for Neuroscience of Natal, Natal, Brazil.
authors.forename: Eric
authors.initials: E
authors.lastname: Thomson
authors.affiliation: Department of Neurobiology, Duke University, Durham, North Carolina;
authors.forename: Jason
authors.initials: J
authors.lastname: Lou
authors.affiliation: Department of Neurobiology, Duke University, Durham, North Carolina;
authors.forename: Kathryn
authors.initials: K
authors.lastname: Sylvester
authors.affiliation: Department of Neurobiology, Duke University, Durham, North Carolina;
authors.forename: Annie
authors.initials: A
authors.lastname: McDonough
authors.affiliation: Department of Neurobiology, Duke University, Durham, North Carolina;
authors.forename: Stefani
authors.initials: S
authors.lastname: Tica
authors.affiliation: Department of Neurobiology, Duke University, Durham, North Carolina; Department of Biomedical Engineering, Duke University, Durham, North Carolina; Department of Psychology and Neuroscience, Duke University, Durham, North Carolina; Center for Neuroengineering, Duke University, Durham, North Carolina; and Edmond and Lily Safra International Institute for Neuroscience of Natal, Natal, Brazil nicoleli@neuro.duke.edu.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Nicolelis
mesh_terms: D000818:Animals; D066187:Basal Forebrain / Q000502:physiology*; D004192:Discrimination, Psychological / Q000502:physiology; D005260:Female; D009474:Neurons / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D012201:Reward; D055698:Touch Perception / Q000502:physiology*; D014738:Vibrissae / Q000502:physiology
keywords: basal forebrain; reward processing; whisker system