Comparison of the physiology of the auditory receptor organs in Gryllus bimaculatus and Ephippiger ephippiger: CSD recordings within the auditory neuropiles.
The syllables of the song of the tettigoniid Ephippiger ephippiger consist of a series of short sound impulses with a broad-banded frequency spectrum. Syllables of the song of the gryllid species Gryllus bimaculatus are nearly pure tones with sharply tuned frequency maxima. A comparison of the physiology of the auditory receptor organs of both species was carried out by using acoustical stimuli with different carrier frequencies and time-amplitude patterns. The neuronal ensemble activity of receptor cell groups of the tympanal organ was measured within the prothoracic ganglion using the CSD technique. In E. ephippiger, response maxima were found at carrier frequencies mirroring the broad frequency content of the conspecific song. The receptor cells of E. ephippiger are highly sensitive to transient sound impulses. In G. bimaculatus, the receptor cell population is more sharply tuned to the basic frequencies of the natural songs; pure tones represent more effective stimuli than transient sound signals. The causes for these species-specific differences are discussed with regard to probable adaptations of the receptor organs to the parameters of the conspecific songs.
Nebeling
B
B
AG Neurobiologie, FB Biologie-Zoologie, Philipps-Universität Marburg, Federal Republic of Germany.
Rössler
W
W
Jatho
M
M
D000161:Acoustic Stimulation; D000818:Animals; D001307:Auditory Perception / Q000502:physiology*; D005260:Female; D006135:Gryllidae / Q000502:physiology*; D007313:Insecta / Q000502:physiology*; D008297:Male; D011984:Sensory Receptor Cells / Q000502:physiology*; D000159:Vestibulocochlear Nerve / Q000502:physiology*