[The role of group-A10 dopamine neurons of the ventral tegmental area in analgesia evoked by electrocutaneous pain stimulation and morphine].

The activity of antinociceptive mechanisms induced by footshock (FS) and morphine injection was studied in experiments on rats with bilateral destruction of group A10 neurones of the ventral tegmental area. The latent periods of the hot plate and tail flick pain reactions to FS and morphine increased significantly in the experimental and control groups as compared to the initial values. In morphine injection these indices were the same in the experimental and control groups. In FS the latent periods of the reaction were significantly greater in the experimental group. Thus, destruction of dopaminergic neurons of A10 nuclei intensifies the antinociceptive effects in FS but has no effect on the pain-relieving action of systemic morphine injection.