Karen A. Manning - US grants

Nearly all sensory information destined for conscious perception is processed first in a central brain region called the thalamus before being sent to cerebral cortex. Sensory signals are actively modified in the thalamus as a function of behavioral state or events. Converging evidence suggests the thalamic reticular nucleus (TRN) is essential to this process; TRN receives input from myriad brain regions, and TRN impacts directly the thalamic neurons that pass the ascending sensory signals on to cortex. Modification of sensory signals in the thalamus has been demonstrated in association with the sleep-wake transition, but little is known about sensory modifications that occur within the awake brain. To address the challenge of understanding the function of TRN in the awake state, this project will determine sensory and non-sensory factors that activate TRN neurons and the consequences of TRN activation on transmission of visual information through the thalamic lateral geniculate nucleus. Preliminary electrophysiological recording, in conjunction with behavioral methods, suggests that TRN neurons have robust visual responses and significant non-visual reward and/or attention-related responses. The project will distinguish these and more fully define the role of TRN neurons in the awake, behaving state. This research will advance significantly understanding of the essential processes in the brain that underlie conscious perception of the world. The project will also provide training opportunities for undergraduate and graduate students within a program recognized nationally for its success in recruiting and retaining underrepresented students in graduate training.