[Effects of vocalization and respiration and fiber connections on hyperstriatum ventrale pars caudale in Fringilla montifringilla].

In urethane-anesthetized Fringilla montifringilla, effects of electrically stimulating the hyperstriatum ventrale pars caudale (HVc) on vocalization and respiration were observed. Central connections of HVc were investigated by means of injecting CB-HRP into HVc. The results were as follows: (1) Electrical stimulation of HVc caused vocal response. (2) Long train electrical pulses stimulation of HVc elicited significant respiratory facilitating effects, that is, increase of respiratory rate and depth. (3) Short train stimulation administered in HVc during inspiratory phase terminated switching-off of inspiration, and during expiratory phases produced the prolongation of expiratory phase so to coordinate vocalization and then increasing the respiratory rate and depth. (4) CB-HRP traces revealed that HVc projected to robust nucleus of the archistriatum, and atea X of lobus parolfactorius. HVc received projections from medial nucleus magnocellularis of the anterior neostriatum, nucleus interfacialis of midneostriatum, telencephalic auditory nucleus-field L, nucleus uvaeformis of the thalamus, and locus ceruleus of the pons. These results showed that, besides vocal control, HVc may be involved in neural regulations of respiratory facilitation, the effect on respiration seeming specific. It is suggested that HVc may play an important role in coordinating singing and respiration.