Neuroendocrine mechanisms that regulate context-dependent behavioral responses to acute stress Public Deposited

http://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/70795c18s

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • In nature, animals survive threats by responding physiologically and behaviorally in ways that are appropriate to the situation. Which responses are appropriate depend on the animals' surroundings and current physiological and behavioral state. This dissertation investigated the neuroendocrine mechanisms that control context-dependent behavioral responses to stress by focusing on the contrasting actions of corticosterone and vasotocin and using an amphibian model (roughskin newt, Taricha granulosa). These two hormones were selected because, in Taricha, the stress steroid corticosterone (CORT) suppresses and the peptide vasotocin (VT) enhances male reproductive behaviors. Behavioral studies confirmed that CORT administration suppresses clasping and that this CORT-induced suppression of clasping is blocked by previous experience of courtship clasping or exposure to VT. Other studies revealed that CORT administration does not suppress clasping behavior by suppressing appetitive responses to visual or olfactory sexual stimuli. Another series of studies tested the hypothesis that the endocaimabinoid system acts on medullary neurons and that the endocannabinoid system is activated by CORT. Behavioral studies revealed that stress-induced and CORT-induced suppression of clasping was blocked by pretreatment with a cannabinoid (CB1) receptor antagonist. Single-unit recording from medullary neurons that control clasping revealed a similar pattern. Spontaneous activity and sensory responsiveness of medullary neurons was suppressed by CORT; this effect was blocked by prior treatment of a cannabinoid antagonist. These studies indicate that endocannabinoid signaling occurs downstream in the temporal sequence of events initiated by acute stress and CORT. Given that CORT and VT interact to alter behavior and medullary neuron activity, and that endocannabinoids mediate CORT-induced suppression of these measures, we predicted that cannabinoids interfere with VT signaling. Behavioral studies indicated that cannabinoid agonist suppresses clasping, but electrophysiological studies revealed mixed responses by medullary neurons. When administered sequentially in behavioral and electrophysiological studies, VT-induced enhancement of clasping behavior and neuronal activity was blocked by prior treatment with a cannabinoid agonist. Together these studies provide evidence that CORT and VT interact, and the temporal nature of their interaction transduces context. One mechanism by which endocrine signals can interact to produce appropriate behavioral responses is by the action of retrograde signaling of endocannabinoids.
Resource Type
Date Available
Date Copyright
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome, 256 Grayscale) using Capture Perfect 3.0.82 on a Canon DR-9080C in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces
Additional Information
  • description.provenance : Submitted by Eric Hepler (ehscanner@gmail.com) on 2011-05-03T18:25:47Z No. of bitstreams: 1 CoddingtonEmma2005.pdf: 6448178 bytes, checksum: d1bb233b0b5b3b348b7edefca5e1f9d2 (MD5)
  • description.provenance : Approved for entry into archive by Patricia Black(patricia.black@oregonstate.edu) on 2011-05-03T19:50:08Z (GMT) No. of bitstreams: 1 CoddingtonEmma2005.pdf: 6448178 bytes, checksum: d1bb233b0b5b3b348b7edefca5e1f9d2 (MD5)
  • description.provenance : Made available in DSpace on 2011-05-03T19:55:21Z (GMT). No. of bitstreams: 1 CoddingtonEmma2005.pdf: 6448178 bytes, checksum: d1bb233b0b5b3b348b7edefca5e1f9d2 (MD5) Previous issue date: 2004-06-08
  • description.provenance : Approved for entry into archive by Patricia Black(patricia.black@oregonstate.edu) on 2011-05-03T19:55:20Z (GMT) No. of bitstreams: 1 CoddingtonEmma2005.pdf: 6448178 bytes, checksum: d1bb233b0b5b3b348b7edefca5e1f9d2 (MD5)

Relationships

In Administrative Set:
Last modified: 08/19/2017

Downloadable Content

Download PDF
Citations:

EndNote | Zotero | Mendeley

Items