Skip to Main Content
 

Global Search Box

 
 
 
 

ETD Abstract Container

Abstract Header

The development of neuropeptidergic phenotypes in autonomic neurons in vivo: Evidence that distinct mechanisms may regulate neuropeptide expression

Tyrrell, Sophia

Abstract Details

1993, Doctor of Philosophy, Case Western Reserve University, Neurosciences.
The mechanisms by which peptidergic phenotypes of autonomic neurons are determined and regulated are incompletely understood. I have examined the development of four neuropeptides in two sympathetic ganglia, the superior cervical ganglion (SCG) and the stellate ganglion. Using immunocytochemistry, radioimmunoassays and in situ hybridization histochemistry, I have shown that neuropeptide Y (NPY), vasoactive intestinal peptide (VIP), enkephalin (Enk) and calcitonin gene related peptide (CGRP) have distinct developmental patterns of expression. Two peptides were expressed in embryonic ganglia; NPY-IR appeared in almost every embryonic sympathetic cell while VIP-IR was present in a subset of stellate cells. The proportion cells possessing immunoreactivity for these peptides decreased during development. In contrast, Enk- and CGRP-IR first appeared postnatally in a small number of neurons. Enk-IR was predominately found in caudal SCG neurons and CGRP-IR was present in stellate neurons. The proportion of neurons expressing Enk and CGRP increased until after P21 when the number of Enk-IR neurons decreased and the proportion of neurons with CGRP-IR no longer changed. Following treatment of neonatal rats with a single dose of 6-hydroxydopamine (6-OHDA), contact between sympathetic neurons and their targets was transiently interrupted and expression of each neuropeptide was affected in a distinct manner: the proportion of neurons with NPY-IR did not change, VIP-IR was increased in the SCG, but not in the stellate ganglion and the proportion of neurons with either Enk- or CGRP-IR was reduced. In separate studies, I have shown that sympathetic neurons can influence the expression of NPY in parasympathetic neurons. Following sympathectomy, the percentage of ciliary neurons with NPY-IR was significantly increased. My data provide evidence that each neuropeptide may be regulated separately. Furthermore, I found that the relationships between peptide-IR and mRNA levels for some neuropeptides change during development, suggesting that the regulation of individual peptides is altered during development. It is possible that the mechanisms regulating neuropeptide expression are as diverse as the phenotypes they generate
Story Landis (Advisor)
284 p.

Recommended Citations

Citations

  • Tyrrell, S. (1993). The development of neuropeptidergic phenotypes in autonomic neurons in vivo: Evidence that distinct mechanisms may regulate neuropeptide expression [Doctoral dissertation, Case Western Reserve University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=case1060782360

    APA Style (7th edition)

  • Tyrrell, Sophia. The development of neuropeptidergic phenotypes in autonomic neurons in vivo: Evidence that distinct mechanisms may regulate neuropeptide expression. 1993. Case Western Reserve University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=case1060782360.

    MLA Style (8th edition)

  • Tyrrell, Sophia. "The development of neuropeptidergic phenotypes in autonomic neurons in vivo: Evidence that distinct mechanisms may regulate neuropeptide expression." Doctoral dissertation, Case Western Reserve University, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=case1060782360

    Chicago Manual of Style (17th edition)