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Full-Text Articles in Veterinary Medicine
Circadian Behavioral Responses To Light And Optic Chiasm-Evoked Glutamatergic Epscs In The Suprachiasmatic Nucleus Of Iprgc Conditional Vglut2 Knock-Out Mice, Michael G. Moldavan, Patricia J. Sollars, Michael R. Lasarev, Charles N. Allen, Gary E. Pickard
Circadian Behavioral Responses To Light And Optic Chiasm-Evoked Glutamatergic Epscs In The Suprachiasmatic Nucleus Of Iprgc Conditional Vglut2 Knock-Out Mice, Michael G. Moldavan, Patricia J. Sollars, Michael R. Lasarev, Charles N. Allen, Gary E. Pickard
School of Veterinary and Biomedical Sciences: Faculty Publications
Intrinsically photosensitive retinal ganglion cells (ipRGCs) innervate the hypothalamic suprachiasmatic nucleus (SCN), a circadian oscillator that functions as a biological clock. ipRGCs use vesicular glutamate transporter 2 (vGlut2) to package glutamate into synaptic vesicles and light-evoked resetting of the SCN circadian clock is widely attributed to ipRGC glutamatergic neurotransmission. Pituitary adenylate cyclase-activating polypeptide (PACAP) is also packaged into vesicles in ipRGCs and PACAP may be coreleased with glutamate in the SCN. vGlut2 has been conditionally deleted in ipRGCs in mice [conditional knock-outs (cKOs)] and their aberrant photoentrainment and residual attenuated light responses have been ascribed to ipRGC PACAP release. However, …
The Neurobiology Of Circadian Rhythms, Patricia J. Sollars, Gary E. Pickard
The Neurobiology Of Circadian Rhythms, Patricia J. Sollars, Gary E. Pickard
School of Veterinary and Biomedical Sciences: Faculty Publications
Daily rhythms in nature, such as the opening and closing of flowers or our patterns of sleep and wakefulness and their association with the perpetual alteration of night and day, were recognized in antiquity although their origins were not questioned until the eighteenth century. The French Astronomer Jean-Jacques d’Ortous de Mairan conducted an investigation into whether the leaves of the Mimosa plant opened in response to light.1 While de Mairan’s experiments were the first to question the origin of such daily rhythms, Augustin Pyramus de Candolle is credited with the first suggestion that they arose through an internal timekeeping …
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 …
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 …