title: Internal Cholinergic Regulation of Learning and Recall in a Model of Olfactory Processing.
abstract: In the olfactory system, cholinergic modulation has been associated with contrast modulation and changes in receptive fields in the olfactory bulb, as well the learning of odor associations in olfactory cortex. Computational modeling and behavioral studies suggest that cholinergic modulation could improve sensory processing and learning while preventing pro-active interference when task demands are high. However, how sensory inputs and/or learning regulate incoming modulation has not yet been elucidated. We here use a computational model of the olfactory bulb, piriform cortex (PC) and horizontal limb of the diagonal band of Broca (HDB) to explore how olfactory learning could regulate cholinergic inputs to the system in a closed feedback loop. In our model, the novelty of an odor is reflected in firing rates and sparseness of cortical neurons in response to that odor and these firing rates can directly regulate learning in the system by modifying cholinergic inputs to the system. In the model, cholinergic neurons reduce their firing in response to familiar odors-reducing plasticity in the PC, but increase their firing in response to novel odor-increasing PC plasticity. Recordings from HDB neurons in awake behaving rats reflect predictions from the model by showing that a subset of neurons decrease their firing as an odor becomes familiar.
authors.affiliation: Computational Physiology Lab, Department of Neurobiology and Behavior, Cornell University Ithaca, NY, USA.
authors.forename: Licurgo
authors.initials: L
authors.lastname: de Almeida
authors.affiliation: Physics Institute Federal University of Rio Grande do Sul (UFRGS) Porto Alegre, Brazil.
authors.forename: Marco
authors.initials: M
authors.lastname: Idiart
authors.affiliation: Computational Physiology Lab, Department of Neurobiology and Behavior, Cornell University Ithaca, NY, USA.
authors.forename: Owen
authors.initials: O
authors.lastname: Dean
authors.affiliation: Computational Physiology Lab, Department of Neurobiology and Behavior, Cornell University Ithaca, NY, USA.
authors.forename: Sasha
authors.initials: S
authors.lastname: Devore
authors.affiliation: Department of Psychology, Cornell University Ithaca, NY, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Smith
authors.affiliation: Computational Physiology Lab, Department of Neurobiology and Behavior, Cornell University Ithaca, NY, USA.
authors.forename: Christiane
authors.initials: C
authors.lastname: Linster
keywords: acetylcholine; learning and memory; olfactory bulb; olfactory cortex; regulation