Release calling and warning crying in Rana pipiens are described and compared with breathing. Vokalizations consist of a vocal phase, which is merely a modification of the expiratory phase of breathing, followed by an inspiratory phase, which is identical to inspiratory phase of breathing. Electrical and mechanical stimulation of the brain and brain lesions are used to locate some of the central mechanisms controlling release calling and warning crying in Rana pipiens, and mating calling in Rana pipiens and a number of hylids (mainly Hyla cinerea). It is concluded that the main control mechanisms are in the trigeminoisthmic tegmentum (below the nucleus isthmi). Mating calling requires, in addition, input transmitted through the ventral thalamus from hormone receptors in the preoptic area. Mating calling can be evoked in hylids by presenting them with recordings of specific calls. The mechanisms for responding to an acoustic stimulus are probably located in the anterior medulla and midbrain tegmentum (below the nucleus isthmi). Mating calling was evoked in two Hyla cinerea females after replacing the ovaries with Rana testes and injecting Rana pituitaries. It is suggested that release calling evolved from breathing, and that warning crying and mating calling may then have evolved from release calling.
The possible importance of the DC resting potential in the physiology of hearing is being intensively studied (see Davis, '59 and '60 for reviews and references). However, the comparative approach to this problem does not yet seem to have been utilized.The purpose of this paper is to throw light upon the origin and evolution of this potential. The main emphasis is on the relative magnitude of the endocochlear potential in different groups and the SUSceptibility of this potential to anoxia. Such studies should also contribute to an understanding of the production and function of the DC potential.It is recognized that this study serves only as a preliminary survey both frolm the standpoint of number of species investigated and the number of individuals per species.
METHODDC recordings DC recordings were made with a Keithley electrometer (model 200B). The active electrode consisted of a Ringer-filled pipette drawn from 3 mm glass tubing. The tip diameter ranged from 2 to 10 LI but was usually within 4 to 6 u. Within this pipette was placed a silver chloride coated, 50 LI, silver wire. For the reference electrode a similar wire was wrapped in a ball of Ringer-soaked cotton and placed on the neck muscles of the animal. The animal was then fastened into an instrument tray to which was attached a manipulator with the electrode. The animal was within a shielded cage during recordings .
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.