The Role of Gabaergic Inhibition in Modulating Receptive Field Size of Cuneate Neurons Thesis

3 79 A8f A*. Blockade of GABAergic inhibition increases receptive field (RF) size of most somatosensory cortex (SI) and some ventrobasal thalamus (VB) neurons. To determine if GABA-mediated inhibition controls RF size of cuneate neurons, GAB A and GAB A receptor antagonists were applied by iontophoresis. Glutamate was applied to determine if firing frequency affected RF size. Twenty-nine of thirty-six neurons showed an RF expansion during GABA A receptor blockade. Eleven of nineteen neurons showed an RF expansion during GABAG receptor blockade. Glutamate affected the RF size of only two of twenty-nine neurons. The results suggest RF size of cuneate neurons may be modulated through GAB A a and GABAG receptors, independent of firing frequency. Northcutt, offered generous technical assistance during the project. B. J. Weisberg, gave constant support and encouragement throughout. My sincere gratitude is offered to all who have collaborated on this project.