[Vocal reactions of chickens to midbrain stimulation with different electrical current parameters].

Vocal reactions of hens are realized via nucleus intercollicularis, nucleus mesencephalicus, nucleus isthmi (pars principalis magnocellularis), nucleus isthmi (pars principalis parvocellularis), formatio reticularis and other midbrain structures. These findings indicate a widespread representation of vocal centre in the midbrain of hens. Functional properties of these structures are different. Intercollicular and dorsal mesencephalic nuclei exhibit higher excitability as compared to isthmic nuclei and the reticular formation. Vocal reactions depend on the parameters of the electrical stimuli. The increase in the amplitude and frequency of stimulation facilitates vocal reaction and changes its pattern.