This thesis explored whether interpretations of the reinforcing effect of stimulation trains used in the self-administration of brain-stimulation (SABS) paradigm were artifacts of the reinforcement schedule chosen or whether it represented a genuine attempt by animals to maintain optimal levels of reward. Results demonstrate that stimulation trains used in SABS are reinforcing and that animals regulate pulse frequency to optimize the level of reward. The thesis then explored whether pedunculopontine tegmental nucleus (PPTg) lesions blocked the acquisition or maintenance of SABS, and the acquisition of eight-arm radial maze learning. Results showed that lesions confined to the PPTg block acquisition and maintenance of SABS, suggesting that the PPTg mediates the positive reinforcing effects of BSR. Further, PPTg lesions blocked win-shift and win-stay radial maze learning. However, results indicate that animals were not impaired in "shifting" or "staying" behavior. It is speculated that PPTg lesions block the reinforcing effects of food, which produce inefficient performance on both memory tasks.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.41660 |
| Date | January 1993 |
| Creators | Lepore, Marino |
| Contributors | Franklin, K. B. J. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Psychology.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001420190, proquestno: NN94657, Theses scanned by UMI/ProQuest. |
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