Electrical activity of the olfactory system

Data have been presented concerning the relationship of nasal air flow to electrical activity in the olfactory system. The close correspondence between the Ottoson slow potential from the bulb and respiratory activity suggests that this slow potential is an excellent measure of respiration. The bursting activity at approximately 40 c/sec in the olfactory bulb appeared to be closely related with the rate and amplitude of the slow potentials, indicating that the slow potential was necessary for the elicitation of the 40 c/sec activity. Similar 40 c/sec activity in the basolateral amygdala was found to occur only at times when this activity was evident in the bulb, but did not occur invariably when 40 c/sec bulb activity was seen. In the shift from sleep to arousal, it was seen that the 40 c/sec activity in the bulb and amygdala did not occur until the first inspiratory cycle. Sniffing associated with active olfactory exploration was evident in the slow potential recordings and was associated with greatly increased 40 c/sec activity in both the bulb and amygdala.