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Full-Text Articles in Medicine and Health Sciences
Intrinsically Photosensitive Retinal Ganglion Cells, Gary E. Pickard, Patricia J. Sollars
Intrinsically Photosensitive Retinal Ganglion Cells, Gary E. Pickard, Patricia J. Sollars
School of Veterinary and Biomedical Sciences: Faculty Publications
Intrinsically photosensitive retinal ganglion cells (ipRGCs) respond to light in the absence of all rod and cone photoreceptor input. The existence of these ganglion cell photoreceptors, although predicted from observations scattered over many decades, was not established until it was shown that a novel photopigment, melanopsin, was expressed in retinal ganglion cells of rodents and primates. Phototransduction in mammalian ipRGCs more closely resembles that of invertebrate than vertebrate photoreceptors and appears to be mediated by transient receptor potential channels. In the retina, ipRGCs provide excitatory drive to dopaminergic amacrine cells and ipRGCs are coupled to GABAergic amacrine cells via gap …
Cell-Type Specific Distribution Of Chloride Transporters In The Rat Suprachiasmatic Nucleus, Michael A. Belenky, Patricia J. Sollars, David B. Mount, Seth L. Alper, Yosef Yarom, Gary E. Pickard
Cell-Type Specific Distribution Of Chloride Transporters In The Rat Suprachiasmatic Nucleus, Michael A. Belenky, Patricia J. Sollars, David B. Mount, Seth L. Alper, Yosef Yarom, Gary E. Pickard
School of Veterinary and Biomedical Sciences: Faculty Publications
The suprachiasmatic nucleus (SCN) is a circadian oscillator and biological clock. Cell-to-cell communication is important for synchronization among SCN neuronal oscillators and the great majority of SCN neurons use γ-aminobutyric acid (GABA) as a neurotransmitter, the principal inhibitory neurotransmitter in the adult central nervous system. Acting via the ionotropic GABAA receptor, a chloride ion channel, GABA typically evokes inhibitory responses in neurons via Cl− influx. Within the SCN GABA evokes both inhibitory and excitatory responses although the mechanism underlying GABA-evoked excitation in the SCN is unknown. GABA-evoked depolarization in immature neurons in several regions of the brain is a function …
Restoration Of Circadian Behavior By Anterior Hypothalamic Heterografts, Patricia J. Sollars, Daniel P. Kimble, Gary E. Pickard
Restoration Of Circadian Behavior By Anterior Hypothalamic Heterografts, Patricia J. Sollars, Daniel P. Kimble, Gary E. Pickard
School of Veterinary and Biomedical Sciences: Faculty Publications
The suprachiasmatic nucleus (SCN) of the anterior hypothalamus (AH) is a circadian oscillator and an important component of the mammalian circadian system. To determine whether the SCN is the dominant circadian pacemaker responsible for generating a species-typical characteristic of circadian rhythms [i.e., period length (T)], neural transplantation was conducted using fetal AH donors of different species and SCN-lesioned (SCNx) hosts. The circadian behavior of each of the three donor species is clearly distinguishable by its species-typical T. The extent of SCN pacemaker autonomy was assessed by noting whether the period of the restored circadian rhythm following heterograft transplantation was characteristic …