[Aging changes of the electro-physiological characteristics of hypothalamic neurons in culture]

The aging changes of the electrophysiological characteristics of the hypothalamic neurons cultured for 0-140 days were studied in neonatal SD rats by the intracellular microelectrode recording technique. The growth velocity of the neurites was used as an index to divide the living process of the neurons into three periods, i.e. recovering period, growth period and aging period. It was found that the time constant and the membrane capacitance reached a top value in the growth period and then decreased significantly in the aging period (P < 0.05, P < 0.01). In the recovering period, the membrane resistance reached the highest; and then decreased significantly in growth period but did not change significantly in the aging period. The amplitude of the membrane resting potential was about -30 - -60 mv and increased with the days in vitro (P < 0.05). The neurons could produce single or burst discharges. It appears that certain electrophysiological characteristics of the hypothalamic neurons in culture could characterize certain aging changes.