Tympanal mechanics and neural responses in the ears of a noctuid moth

Publication Type:Journal Article
Year of Publication:2011
Authors:Hofstede, HM ter, Goerlitz, HR, Montealegre-Z, F, Robert, D, Holderied, MW
Journal:Naturwissenschaften
Volume:98
Questão:12
Pagination:1057 - 1061
Date Published:Jan-12-2011
ISSN:0028-1042
Palavras-chave:Auditory threshold, Lepidoptera, Moth auditory biomechanics, Neurophysiology
Abstract:

Ears evolved in many groups of moths to detect the echolocation calls of predatory bats. Although the neurophysiology of bat detection has been intensively studied in moths for decades, the relationship between sound-induced movement of the noctuid tympanic membrane and action potentials in the auditory sensory cells (A1 and A2) has received little attention. Using laser Doppler vibrometry, we measured the velocity and displacement of the tympanum in response to pure tone pulses for moths that were intact or prepared for neural recording. When recording from the auditory nerve, the displacement of the tympanum at the neural threshold remained constant across frequencies, whereas velocity varied with frequency. This suggests that the key biophysical parameter for triggering action potentials in the sensory cells of noctuid moths is tympanum displacement, not velocity. The validity of studies on the neurophysiology of moth hearing rests on the assumption that the dissection and recording procedures do not affect the biomechanics of the ear. There were no consistent differences in tympanal velocity or displacement when moths were intact or prepared for neural recordings for sound levels close to neural threshold, indicating that this and other neurophysiological studies provide good estimates of what intact moths hear at threshold.

URL:http://link.springer.com/10.1007/s00114-011-0851-7
DOI:10.1007/s00114-011-0851-7
Short Title:Naturwissenschaften
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith