QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online May 8, 2007
Journal of Experimental Biology 210, 1834-1845 (2007)
Published by The Company of Biologists 2007
doi: 10.1242/jeb.001495

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Fonseca, P. J. Articles by Correia, T. Search for Related Content PubMed PubMed Citation Articles by Fonseca, P. J. Articles by Correia, T. Social Bookmarking                         What's this?

Effects of temperature on tuning of the auditory pathway in the cicada Tettigetta josei (Hemiptera, Tibicinidae)

P. J. Fonseca^* and T. Correia

Departamento de Biologia Animal e Centro de Biologia Ambiental, Faculdade de Ciências da Universidade de Lisboa, Bloco C2, Campo Grande, 1749-016 Lisboa, Portugal

^* Author for correspondence (e-mail: pjfonseca{at}fc.ul.pt)

Accepted 7 March 2007

The effects of temperature on hearing in the cicada Tettigetta josei were studied. The activity of the auditory nerve and the responses of auditory interneurons to stimuli of different frequencies and intensities were recorded at different temperatures ranging from 16°C to 29°C.

Firstly, in order to investigate the temperature dependence of hearing processes, we analyzed its effects on auditory tuning, sensitivity, latency and Q_10dB. Increasing temperature led to an upward shift of the characteristic hearing frequency, to an increase in sensitivity and to a decrease in the latency of the auditory response both in the auditory nerve recordings (periphery) and in some interneurons at the metathoracic–abdominal ganglionic complex (MAC). Characteristic frequency shifts were only observed at low frequency (3–8 kHz). No changes were seen in Q_10dB. Different tuning mechanisms underlying frequency selectivity may explain the results observed.

Secondly, we investigated the role of the mechanical sensory structures that participate in the transduction process. Laser vibrometry measurements revealed that the vibrations of the tympanum and tympanal apodeme are temperature independent in the biologically relevant range (18–35°C). Since the above mentioned effects of temperature are present in the auditory nerve recordings, the observed shifts in frequency tuning must be performed by mechanisms intrinsic to the receptor cells.

Finally, the role of potassium channels in the response of the auditory system was investigated using a specific inhibitor of these channels, tetraethylammonium (TEA). TEA caused shifts on tuning and sensitivity of the summed response of the receptors similar to the effects of temperature. Thus, potassium channels are implicated in the tuning of the receptor cells.

Key words: cicada, Tettigetta josei, hearing, temperature

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				J. F. C. Windmill, J. Sueur, and D. Robert The next step in cicada audition: measuring pico-mechanics in the cicada's ear J. Exp. Biol., December 15, 2009; 212(24): 4079 - 4083. [Abstract] [Full Text] [PDF]