Skip to Main Content
 

Global Search Box

 
 
 
 

ETD Abstract Container

Abstract Header

Regulation of neuropeptide release in the SCN circadian clock: in vivo assessments of NPY, VIP, and GRP

Francl, Jessica M.

Abstract Details

2010, PHD, Kent State University, College of Arts and Sciences / Department of Biological Sciences.
The suprachiasmatic nucleus (SCN) of the hypothalamus is responsible for generating and maintaining circadian rhythms in mammals. Interneuronal communication in the SCN occurs via neurotransmitter and neuropeptide release, with glutamate, γ-aminobutyric acid (GABA), serotonin (5-HT), neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), gastrin-releasing peptide (GRP), and arginine vasopressin (AVP) being the neurochemicals most commonly associated with SCN regulation (reviewed by Reghunandanan and Reghunandanan, 2006). Photic and nonphotic stimuli are received by the SCN and this information is integrated by the SCN, ultimately resulting in a cohesive rhythm output that is entrained to stimulus input. Much data is currently available regarding in vitro actions and rhythmic profiles of release of these SCN neurochemicals through bath application procedures, electrophysiological recordings, immunocytochemistry, and in situ hybridization. However, to date there are few reports on the in vivo release of these agents, and notably neuropeptides from the SCN. The studies performed here used brain microdialysis techniques coupled with sensitive radioimmunoassay to determine the in vivo release over a 24-hr period of three SCN neuropeptides (NPY, VIP, and GRP) in a freely-behaving animal model; additionally, these studies examined the effects of pharmacological agents on the release of these peptides, including both photic and nonphotic stimuli. These experiments are the first to elucidate the in vivo release patterns of NPY, VIP, and GRP from the hamster SCN and provide crucial information regarding the timing of neuropeptide release that can then be used to elucidate possible functions of these peptides within the SCN. The results of these experiments conclude that these neuropeptides are released rhythmically in the SCN and that they are of synaptic origin. It was also shown that these neuropeptides are modulated by photic and nonphotic input signals to the clock. Such information sheds light on the possible functions of these neuropeptides with respect to photic and nonphotic regulation and timing of the mammalian SCN circadian clock.
J. David Glass, PhD (Advisor)
Eric M. Mintz, PhD (Committee Member)
Robert V. Dorman, PhD (Committee Member)
Brian P. Bagatto, PhD (Committee Member)
William Lynch, PhD (Committee Member)
115 p.

Recommended Citations

Citations

  • Francl, J. M. (2010). Regulation of neuropeptide release in the SCN circadian clock: in vivo assessments of NPY, VIP, and GRP [Doctoral dissertation, Kent State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=kent1289328898

    APA Style (7th edition)

  • Francl, Jessica. Regulation of neuropeptide release in the SCN circadian clock: in vivo assessments of NPY, VIP, and GRP. 2010. Kent State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=kent1289328898.

    MLA Style (8th edition)

  • Francl, Jessica. "Regulation of neuropeptide release in the SCN circadian clock: in vivo assessments of NPY, VIP, and GRP." Doctoral dissertation, Kent State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=kent1289328898

    Chicago Manual of Style (17th edition)