Discharge properties of mitral/tufted cells in the olfactory bulb of cats.

The spontaneous activity of mitral/tufted cells of the cat olfactory bulb was subjected to time-series analysis. Ninety percent of 284 cells displayed either bimodal or skewed distribution under both tracheal and nasal respiration, indicating that the spontaneous activity is characterized by burst discharge. We conclude that the source of the burst discharge originates in the olfactory bulb, rather than being induced by nasal airflow or by centrifugal inputs to the olfactory bulb.