RESUMO
In the frog isolated n. n. ischiadici, under permanent low-intensity laser radiation (6328 A; 0.5 mVt), the physiological lability of tissue changed in a monophasic manner towards consecutive growth. After a single illumination lasting from 1 sec to 10 min, statistically significant shifts of the maximal rhythm of impulse excitation towards an increase occur with some "latency" at the 10-min exposure. The maximal frequency of evoked action potentials, at that, invariably remained at the attained level. After the laser action, the irradiated portion of the nerve becomes electropositive in regard to other, intact points of the nerve. The polarization shifts are weak and not directly dependent on the exposure dose of the irradiation. The laser is concluded to evoke an increase and acceleration of metabolic processes which raises the lability level, hence the increased working capacity of the tissue.
