University of Illinois Urbana-Champaign

Experience, neuroanatomical plasticity and expression of the immediate early gene ZENK in the visual cortex of weanling rats

Wallace, Christopher Smith

This item is only available for download by members of the University of Illinois community. Students, faculty, and staff at the U of I may log in with your NetID and password to view the item. If you are trying to access an Illinois-restricted dissertation or thesis, you can request a copy through your library's Inter-Library Loan office or purchase a copy directly from ProQuest.

Permalink

https://hdl.handle.net/2142/21953

Description

Title
Experience, neuroanatomical plasticity and expression of the immediate early gene ZENK in the visual cortex of weanling rats
Author(s)
Wallace, Christopher Smith
Issue Date
1994
Doctoral Committee Chair(s)
Greenough, William T.
Department of Study
Biology, Neuroscience
Discipline
Biology, Neuroscience
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Keyword(s)
Biology, Neuroscience
Language
eng
Abstract
  • This investigation combines anatomical and molecular approaches to determine if expression of a specific regulatory transcription factor correlates with morphological plasticity, using a model of experience-dependent plasticity.
  • An initial study (Chapter 2) demonstrated that exposing weanling rats to a complex environment (EC) rapidly altered dendritic fields of neurons in visual cortex relative to littermates housed in individual cages (IC). This paradigm was employed to assess the behavioral induction of ZENK, a transcription factor implicated in plasticity by its association with hippocampal long-term potentiation.
  • Messenger RNA levels were quantified by in situ hybridization to determine if ZENK is: (1) behaviorally regulated (2) elevated in the visual cortex of rats actively exploring a complex environment (EC). To assess behavioral regulation, three groups were compared: EC; individually caged, but handled (HIC); and unhandled individually caged (IC) rats after short-term differential housing. Within the area of visual cortex where dendritic changes occur after short-term EC (Oc2), the three groups displayed significantly different levels of ZENK expression; EC $>$ HIC $>$ IC. In contrast, in a cortical region within which dendritic plasticity is undetectable (Fr2), no differences were observed in ZENK expression. Superficial cortical layers in Oc2, somatosensory and Fr1 were all significantly elevated in EC relative to controls, suggesting sensory afferent projections to cortex are an important component. Induction of ZENK in the striatum of EC rats suggests that plasticity of this structure may be part of the brain's response to environmental complexity.
  • The anatomical distribution of ZENK mRNA was similar in all behavioral groups. A modular pattern of ZENK labeling in the cortex of all groups was observed and may implicate ZENK in cortical integration.
  • ZENK elevation in EC visual cortex was observed at 4, 15 and 30 days of exposure. Hence, the process(es) ZENK mediates continue throughout the 30 day period. The time course of ZENK induction or the efficiency of translation could vary, however, in response to behavioral stimulation at these different ages.
  • These results indicate that the transcription factor ZENK is sensitive to behavioral stimulation and may regulate the cellular support of, or preparation for, plasticity.
Type of Resource
text
Permalink
http://hdl.handle.net/2142/21953
Copyright and License Information
Copyright 1994 Wallace, Christopher Smith

Owning Collections

Graduate Dissertations and Theses at Illinois PRIMARY
Graduate Theses and Dissertations at Illinois