Electrical activity of the olfactory bulb. Changes induced by lesions of contralateral olfactory areas

Control values for a) trains of sinusoidal waves, b) slow potentials and c) basal activity, were determined in rabbits whose olfactory bulbs (O.B.'s) had been implanted with chronic electrodes. One olfactory epithelium was destroyed in one group of animals and the activity of the contralateral O.B. was analyzed for 7 days. Then, the olfactory peduncle homolateral to the olfactory epithelium previously destroyed was sectioned and the bulbar activity recorded for 15 days. In another group of animals, the olfactory peduncle was sectioned and the activity of the contralateral O.B. analyzed similarly to the previous group. It was observed that no changes occurred in the contralateral O.B. after the destruction of the receptors. The sectioning of the olfactory peduncle produced a temporary increase in the amplitude and duration of the trains of sinusoidal waves from the contralateral O.B. and, only in few cases, in the amplitude of the slow potentials. These results were related to the various nervous structures that had been damaged during the operations.