Краткое описание

We investigate the influence of noradrenaline on voltage-dependent calcium currents (VDCCs) in trigeminal ganglion neurons (TGN) cultivated with and without nerve growth factors (NGF). Application of noradrenaline (100 µmol/L) did not evoke changes in low-threshold VGCCs, but suppressed high-threshold VGCCs. In particular, it caused a decrease in the amplitude of high-threshold VDCCs in presence of NGF and without it by (30 ± 5) and 13 ± 8%, respectively. An inhibition of the fast component of high-threshold VDCCs was observed in majority of TGN which cultivated with NGF. The above-mentioned changes in kinetics occurred in 11 of 13 neurons in the culture with NGF, and only in 3 of 15 neurons in NGF-free culture. The results of experiments have shown the interrelations between the adrenergic modulation of VDCCs and level of NGF. At that, only high-threshold VDCCs are involved in adrenergic modulation of electrical activity. Thus, an increase in the NGF level not only triggers the mechanisms of sprouting of sympathetic fibers, but also leads to an increase in adrenergic effects on sensory signal transmission.