The Effect of X-Rays on the Activity of Neurons in the Rat Olfactory Bulb

Abstract

Extracellular microelectrode recordings were made from single neurons of the olfactory bulb in anethestized rats. Approximately 15% of the units examined responded (usually by an increase in frequency) to 250-kvp X-irradiation at dose rates of 1.5 to 2.0 r/sec when exposures of the whole animal, head only, or olfactory bulb region were made. No responses to irradiation were observed when exposures were made of the body only, the head posterior to the olfactory bulb, or the anterior 5 to 8 mm of the head. Ethyl alcohol perfused through the nasal cavities of tracheotomized rats abolished all responses to radiation. After perfusion of normal saline through the nasal cavities, responses of units to irradiation were readily obtained. In units studied both before and after perfusion of saline through the nasal cavities, the response was usually abolished temporarily. It was concluded that X-irradiation can in some way stimulate olfactory receptors.