NEUROMODULATORY ACTIONS OF THYROTROPIN-RELEASING HORMONE UPON STRESS-INDUCED ANALGESIA.
Item
-
Title
-
NEUROMODULATORY ACTIONS OF THYROTROPIN-RELEASING HORMONE UPON STRESS-INDUCED ANALGESIA.
-
Identifier
-
AAI8614662
-
identifier
-
8614662
-
Creator
-
BUTLER, PAMELA D.
-
Contributor
-
Richard J. Bodnar
-
Date
-
1986
-
Language
-
English
-
Publisher
-
City University of New York.
-
Subject
-
Psychology, Psychobiology
-
Abstract
-
Thyrotropin-releasing hormone (TRH), a peptide with a wide central nervous system distribution, produces some centrally-mediated effects that are unrelated to its neuroendocrine actions. Although TRH itself elicits a transient analgesia, it antagonizes neurotensin analgesia and has mixed effects upon opioid analgesia. The purpose of this dissertation was to determine further the characteristics of the modulatory actions of TRH upon analgesic processes by examining its effects upon several forms of stress-induced analgesia (SIA) which have different pharmacological profiles. First, the results showed that while TRH itself only produced transient analgesia, it produced long-term potentiations of analgesia elicited by exposure to 20 or 80 footshocks delivered to all four paws, and analgesia elicited by brief shock delivered to the forepaws but not the hindpaws. Second, TRH potentiated analgesia elicted by acute exposure to swim temperatures ranging from 2 to 21 C. These effects appeared to be centrally-mediated since TRH potentiated both swim and shock analgesia following intracerebroventricular, but not intravenous, administration. TRH's effects on swim analgesia may be due in part to its metabolism to histidyl-proline diketopiperazine (DKP) since this metabolite produced similar potentiations. However, the stable TRH analogue RX77368 also potentiated swim analgesia. Since the cholinergic system has been implicated in swim analgesia and TRH interacts with the cholinergic system, the observation that TRH potentiated analgesia induced by the muscarinic receptor agonist polocarpine provides preliminary evidence for a possible cholinergic link in the TRH potentiation of various forms of SIA. Thus, while TRH itself has only transient analgesic properties, it is capable of producing long-term modulation of other forms of analgesia such as those produced by stress.
-
Type
-
dissertation
-
Source
-
PQT Legacy CUNY.xlsx
-
degree
-
Ph.D.
-
Program
-
Psychology
