Effects of Noise on Eosinophil Levels of Audiogenic-Seizure-Susceptible and Seizure-Resistant Mice

Abstract

Occurrence of a diurnal rhythm in circulating eosinophils is described in mice selected on the basis of susceptibility to sound-induced seizures. Daily exposures of seizure-susceptible and seizure-resistant mice to single, short noise bursts for 30 days does not abolish or alter this rhythm, provided a recovery period is allowed between the last stimulation and the time of blood sampling. A single noise stimulus is followed by a moderate eosinopenia in seizure-resistant mice and a marked eosinopenia in seizure-susceptible mice in about 3 hours; recovery occurs in both cases within 24 hours. A prolonged eosinopenia occurs with several successive noise bursts[long dash] at a moderately low level (about 250 eosinophils/mm3 blood) in seizure-resistant mice and at lower levels (about 100 eosinophils/ mm3 blood) in mice which experience convulsions during treatment. It was concluded that noise stimulation acts as a mild stress stimulus and is harmful only when it results in the production of fatal convulsions.