It has been proposed that the spectacular olfactory learning capabilities of the rat may prove useful in the development of rodent models of human amnesia. In particular, it has been suggested that rats show a 'primate-like' learning capacity when tested with olfactory (rather than visual or auditory) cues; and that this learning is sensitive to damage to brain stuctures considered critical in the human amnesic syndrome. The aim of this thesis is to evaluate and exploit these claims in the investigation of the neurobiology of rodent olfactory learning. In a series of experiments, an automated 'olfactory maze' is developed for the demonstration and measurement of rodent olfactory learning capacity, and parallels between rodent and primate learning capabilities are investigated. It is concluded that the suggestion that rats form 'primate-like' learning sets (and therefore learn complex abstract rules) when trained on a series of novel olfactory problems is unlikely to be correct. Investigation of the effects of hippocampal and dorsomedial thalamic nucleus (DMN) lesions on olfactory learning do not support the hypothesis that olfactory learning is sensitive to damage to the structures considered critical in human amnesia; hippocampal lesions are without effect, and DMN lesions appear to cause a perceptual, rather than cognitive, abnormality. Infusion of the N-methyl D-aspartate receptor in antagonist AP5, widely used as a tool to investigate the role of synaptic plasticity in learning, is also without effect. Hippocampally lesioned animals are, however, demonstrated to be impaired in a spatial reference memory task. On this basis, it is concluded that rodent olfactory learning does not constitute a useful model for the investigation of the biology of human amnesia.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:661021 |
| Date | January 1993 |
| Creators | Reid, Ian C. |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/20140 |
Page generated in 0.0014 seconds