Growth alteration in the auditory cortex of visually deprived mice

Abstract

Abstract The diameter of cell nuclei and mean volume of internuclear material per nucleus were determined in the auditory cortex in growing and adult mice. The influence of stay in complete darkness for 2–4 months was investigated. In growing mice, a decrease in nuclear size and relative volume of internuclear material was observed after two months in the dark from birth. Prolonged stay in the dark caused an increase in nuclear size and internuclear material, and the hypotrophy of the auditory cortex was succeeded by hypertrophy after four months in the dark from birth. In adult mice, reared in darkness for three months from four to seven months of age, similar hypertrophy of the auditory cortex was recorded. Compared to the findings in the striate cortex of visually deprived mice (in a previous investigation), the initial hypotrophy of the auditory cortex after visual deprivation was less pronounced than the hypotrophy of the auditory cortex after visual cortex. In the latter, no late hypertrophy occurred after prolonged stay in the dark, and hypotrophy was found in the adult, visually deprived mice, and not hypertrophy as in the auditory cortex. The possibility of compensatory auditory training and cortical hypertrophy is discussed.