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Full-Text Articles in Psychology
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
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, …
The Contribution Of The Pineal Gland On Daily Rhythms And Masking In Diurnal Grass Rats, Arvicanthis Niloticus, Dorela D. Shuboni, Amna A. Agha, Thomas K. H. Groves, Andrew J. Gall
The Contribution Of The Pineal Gland On Daily Rhythms And Masking In Diurnal Grass Rats, Arvicanthis Niloticus, Dorela D. Shuboni, Amna A. Agha, Thomas K. H. Groves, Andrew J. Gall
Faculty Publications
Melatonin is a hormone rhythmically secreted at night by the pineal gland in vertebrates. In diurnal mammals, melatonin is present during the inactive phase of the rest/activity cycle, and in primates it directly facilitates sleep and decreases body temperature. However, the role of the pineal gland for the promotion of sleep at night has not yet been studied in non-primate diurnal mammalian species. Here, the authors directly examined the hypothesis that the pineal gland contributes to diurnality in Nile grass rats by decreasing activity and increasing sleep at night, and that this could occur via effects on circadian mechanisms or …
Suprachiasmatic Nucleus And Subparaventricular Zone Lesions Disrupt Circadian Rhythmicity But Not Light-Induced Masking Behavior In Nile Grass Rats, Andrew J. Gall, Dorela D. Shuboni, Lily Yan, Antonio A. Nunez, Laura Smale
Suprachiasmatic Nucleus And Subparaventricular Zone Lesions Disrupt Circadian Rhythmicity But Not Light-Induced Masking Behavior In Nile Grass Rats, Andrew J. Gall, Dorela D. Shuboni, Lily Yan, Antonio A. Nunez, Laura Smale
Faculty Publications
The ventral subparaventricular zone (vSPVZ) receives direct retinal input and influences the daily patterning of activity in rodents, making it a likely candidate for the mediation of acute behavioral responses to light (i.e., masking). We performed chemical lesions aimed at the vSPVZ of diurnal grass rats (Arvicanthis niloticus) using N-methyl-D,L-aspartic acid (NMA), a glutamate agonist. Following NMA lesions, we placed grass rats in various lighting conditions (e.g., 12:12 light-dark, constant dark, constant light); presented a series of light pulses at circadian times (CT) 6, 14, 18, and 22; and placed them in a 7-h ultradian cycle to assess behavioral masking. …
Intergeniculate Leaflet Lesions Result In Differential Activation Of Brain Regions Following The Presentation Of Photic Stimuli In Nile Grass Rats, Andrew J. Gall, Lily Yan, Laura Smale, Antonio A. Nunez
Intergeniculate Leaflet Lesions Result In Differential Activation Of Brain Regions Following The Presentation Of Photic Stimuli In Nile Grass Rats, Andrew J. Gall, Lily Yan, Laura Smale, Antonio A. Nunez
Faculty Publications
The intergeniculate leaflet (IGL) plays an important role in the entrainment of circadian rhythms and the mediation of acute behavioral responses to light (i.e., masking). Recently, we reported that IGL lesions in diurnal grass rats result in a reversal in masking responses to light as compared to controls. Here, we used Fos as a marker of neural activation to examine the mechanisms by which the IGL may influence this masking effect of light in grass rats. Specifically, we examined the patterns of Fos activation in retinorecipient areas and in brain regions that receive IGL inputs following 1-h light pulses given …