Balcita-Pedicino, Judith Joyce
(2008)
Lateral Hypothalamic Projections to the Rat Ventral Tegmental Area: Potential Anatomical Substrates for Adaptive Integration of Behaviors Mediated by Ascending Dopamine Systems.
Master's Thesis, University of Pittsburgh.
(Unpublished)
Abstract
Complex motor behaviors enable mammals to adapt to their internal and external environments. The lateral hypothalamic area (LHA) contributes importantly to autonomic and endocrine regulation, behavioral states, and energy balance. Orexin (Orx) neuropeptides, produced exclusively by LHA cells, are crucial in the integration of sleep and arousal. The LHA projects densely to the ventral tegmental area (VTA), a dopamine (DA) region that is essential for modulating goal-directed behaviors. Extensive investigations of reward function implicate the LHA-VTA connectivity, an arrangement not yet characterized in detail at the ultrastructural level. The present research sought to clarify the precise interactions of LHA axons with VTA cells. Considering reported physiological responses of VTA cells to LHA stimulation and Orx actions, we hypothesized that both projections interact heavily with DA and GABA cell groups in the VTA, and that LHA axons provide a predominant inhibitory innervation. We used immunocytochemistry to visualize DA or GABA neurons in combination with 1) tract tracer identification of LHA axons or 2) immunolabeling for Orx. Electron microscopic analysis of the VTA revealed that, while the bulk of LHA and Orx projections pass through the VTA, their connections with DA and GABA neurons are a complementary mixture of excitatory and inhibitory synapses. The details of morphology herein suggest many different mechanisms of signal transmission by which LHA axons might contribute information concerning interoceptive state to the adaptive performance of complex motor behaviors modulated by the VTA.
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Details
| Item Type: |
University of Pittsburgh ETD
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| Status: |
Unpublished |
| Creators/Authors: |
| Creators | Email | Pitt Username | ORCID  |
|---|
| Balcita-Pedicino, Judith Joyce | balcitaj@pitt.edu | BALCITAJ | |
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| ETD Committee: |
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| Date: |
17 January 2008 |
| Date Type: |
Completion |
| Defense Date: |
14 August 2007 |
| Approval Date: |
17 January 2008 |
| Submission Date: |
20 August 2007 |
| Access Restriction: |
5 year -- Restrict access to University of Pittsburgh for a period of 5 years. |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Dietrich School of Arts and Sciences > Neuroscience |
| Degree: |
MS - Master of Science |
| Thesis Type: |
Master's Thesis |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
electron microscopy; GABA; hypocretin; midbrain; ultrastructure; hypothalamus; orexin |
| Other ID: |
http://etd.library.pitt.edu/ETD/available/etd-08202007-162605/, etd-08202007-162605 |
| Date Deposited: |
10 Nov 2011 20:00 |
| Last Modified: |
15 Nov 2016 13:49 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/9212 |
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