Psychology Commons^™

Normal Behavioral Responses To Light And Darkness And The Pupillary Light Reflex Are Dependent Upon The Olivary Pretectal Nucleus In The Diurnal Nile Grass Rat, Andrew J. Gall, Ohanes S. Khacherian, Brandi Ledbetter, Sean P. Deats, Megan Luck, Laura Smale, Lily Yan, Antonio A. Nunez

Faculty Publications

The olivary pretectal nucleus (OPT) is a midbrain structure that receives reciprocal bilateral retinal projections, is involved in the pupillary light reflex, and connects reciprocally with the intergeniculate leaflet (IGL), a retinorecipient brain region that mediates behavioral responses to light pulses (i.e., masking) in diurnal Nile grass rats. Here, we lesioned the OPT and evaluated behavioral responses in grass rats to various lighting conditions, as well as their anxiety-like responses to light exposure. While control grass rats remained diurnal, grass rats with OPT lesions exhibited a more night-active pattern under 12h:12h light-dark (LD) conditions. However, when placed in constant darkness, …