Interaction between intracortical inhibitory circuits in the motor cortex of Parkinson's disease patients.
Published: 2007
Language: eng
Number of pages: 111
ISBN-13: 9780494273708
Description: Abnormal cortical inhibition in the motor cortex of Parkinson's Disease (PD) patients may be responsible for hypokinetic movements. Transcranial magnetic stimulation (TMS) can be used to non-invasively evaluate different cortical inhibitory circuits. These include short interval intracortical inhibition (SICI), mediated by GABAA receptors, and long interval intracortical inhibition (LICI), mediated by GABAB receptors. In PD, SICI has been suggested to be decreased while LICI is increased. A possible explanation is that LICI inhibits SICI through a presynaptic GABAB mechanism. This thesis focused on testing this hypothesis and we characterized how LICI influences SICI in PD patients. Our observations demonstrate that the inhibitory effect of LICI on SICI was reduced in PD when compared to controls and was not corrected by dopaminergic medication. This suggests there is abnormal presynaptic inhibition in PD. Additionally, our results also suggest that the time course for presynaptic GABAB inhibition is different from that of postsynaptic GABAB inhibition.
Notes: Source: Masters Abstracts International, Volume: 45-06, page: 3065.

Thesis (M.Sc.)--University of Toronto, 2007.

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