Program#/Poster#: 758.15/AA14 Title: Periodic bursting of cholinergic neurons in the owl midbrain signals relative salience of sensory stimuli Location: South Hall A Presentation Time: Wednesday, Oct 21, 2009, 10:00 AM -11:00 AM Authors: *A. ASADOLLAHI, E. I. KNUDSEN; Neurobio., Stanford Univ., Stanford, CA Abstract: Oscillations in neuronal activity have been shown to be linked to stimulus selection and attention in a range of structures and species, including humans. Here we analyzed periodic bursting activity of neurons in the nucleus isthmi pars parvocellularis (Ipc); (nucleus parabigeminus in mammals), a topographically organized cholinergic nucleus that interconnects reciprocally and topographically with the optic tectum (superior colliculus in mammals). Optic tectum is a structure known to contribute to gaze control and spatial attention. We recorded the extracellular responses of IPC neurons to visual and auditory stimuli. When a visual or auditory stimulus presented inside their excitatory receptive field they discharge bursts of spikes with a dominant periodicity of 30-40 Hz. Presenting a second strong stimulus outside a neuron receptive field reduces the power of the periodic activity in response to the receptive field stimulus. The magnitude of reduction in power of the periodicity depends on the relative strength of the stimuli inside and outside the receptive field. The comparison of stimulus strength is global and independent of stimulus feature and modality. These observations show that cholinergic neurons in the IPC signal the location of the most salient stimulus in space as periodic bursts of spikes. Disclosures: A. Asadollahi, None; E.I. Knudsen, None. Keyword(s): ATTENTION VISION OSCILLATION Support: NIH9R01ey019179-29 [Authors]. [Abstract Title]. Program No. XXX.XX. 2009 Neuroscience Meeting Planner. Chicago, IL: Society for Neuroscience, 2009. Online. 2009 Copyright by the Society for Neuroscience all rights reserved. Permission to republish any abstract or part of any abstract in any form must be obtained in writing by SfN office prior to publication.

Keywords