NADPH-diaphorase activity in the motor neurons of different spinal cord segments of albino rat under normal conditions and after deafferentation
Age changes of NADPH-diaphorase activity were studied histochemically in the ventral horn motor neurons at different segmental levels of the spinal cord of rats aged 3-90 days both under normal conditions and in the model of deafferentation (by intraperitoneal capsaicin injection). Wave-like age changes of motor neuron enzyme activity were detected at the level of T<sub>II</sub>, L<sub>IV</sub> and S<sub>II</sub> spinal segments with its increase by day 60 followed by a significant decrease to day 90. Age dynamics of NADPH-diaphorase activity development in the spinal cord motor neurons of intact rats characterizes the constructive processes in neurons, while the changes found after the deafferentation are indicative of the motor neuron damage and are manifested by an abrupt increase of the enzyme activity at the age of 90 days.