Document Type
Article
Publication Date
10-17-2019
Publication Source
Journal of Biological Rhythms
Volume Number
35
Issue Number
1
First Page
45
Last Page
57
Publisher
SAGE
ISSN
0748-7304
Abstract
The circadian system regulates daily rhythms of physiology and behavior. Although extraordinary advances have been made to elucidate the brain mechanisms underlying the circadian system in nocturnal species, less is known in diurnal species. Recent studies have shown that retinorecipient brain areas such as the intergeniculate leaflet (IGL) and olivary pretectal nucleus (OPT) are critical for the display of normal patterns of daily activity in diurnal grass rats (Arvicanthis niloticus). Specifically, grass rats with IGL and OPT lesions respond to light in similar ways to intact nocturnal animals. Importantly, both the IGL and OPT project to one another in nocturnal species, and there is evidence that these 2 brain regions also project to the superior colliculus (SC). The SC receives direct retinal input, is involved in the triggering of rapid eye movement sleep in nocturnal rats, and is disproportionately large in the diurnal grass rat. The objective of the current study was to use diurnal grass rats to test the hypothesis that the SC is critical for the expression of diurnal behavior and physiology. We performed bilateral electrolytic lesions of the SC in female grass rats to examine behavioral patterns and acute responses to light. Most grass rats with SC lesions expressed significantly reduced activity in the presence of light. Exposing these grass rats to constant darkness reinstated activity levels during the subjective day, suggesting that light masks their ability to display a diurnal activity profile in 12:12 LD. Altogether, our data suggest that the SC is critical for maintaining normal responses to light in female grass rats.
Keywords
superior colliculus, circadian, masking, grass rat, diurnality, behavior
Recommended Citation
Repository citation: Gall, Andrew J.; Goodwin, Alyssa M.; Khacherian, Ohanes S.; and Teal, Laura B., "Superior Colliculus Lesions Lead to Disrupted Responses to Light in Diurnal Grass Rats (Arvicanthis niloticus)" (2019). Faculty Publications. Paper 1489.
https://digitalcommons.hope.edu/faculty_publications/1489
Published in: Journal of Biological Rhythms, Volume 35, Issue 1, October 17, 2019, pages 45-57. Copyright © 2019 SAGE.
Comments
Gall, A. J., Goodwin, A. M., Khacherian, O. S., & Teal, L. B. (2020). Superior Colliculus Lesions Lead to Disrupted Responses to Light in Diurnal Grass Rats (Arvicanthis niloticus). Journal of Biological Rhythms, 35(1), 45–57. Copyright © 2019 The Author(s)
https://doi.org/10.1177/0748730419881920