title: Hearing ability decreases in ageing locusts.
abstract: Insects display signs of ageing, despite their short lifespan. However, the limited studies on senescence emphasize longevity or reproduction. We focused on the hearing ability of ageing adult locusts, Schistocerca gregaria. Our results indicate that the youngest adults (2 weeks post-maturity) have a greater overall neurophysiological response to sound, especially for low frequencies (<10 kHz), as well as a shorter latency to this neural response. Interestingly, when measuring displacement of the tympanal membrane that the receptor neurons directly attach to, we found movement is not directly correlated with neural response. Therefore, we suggest the enhanced response in younger animals is due to the condition of their tissues (e.g. elasticity). Secondly, we found the sexes do not have the same responses, particularly at 4 weeks post-adult moult. We propose female reproductive condition reduces their ability to receive sounds. Overall our results indicate older animals, especially females, are less sensitive to sounds.
authors.affiliation: Centre for Ultrasonic Engineering, Department of Electronic and Electrical Engineering, University of Strathclyde, 204 George Street, Glasgow G1 1XW, UK Shira.Gordon@ars.usda.gov james.windmill@strath.ac.uk.
authors.forename: Shira D
authors.initials: SD
authors.lastname: Gordon
authors.affiliation: Centre for Ultrasonic Engineering, Department of Electronic and Electrical Engineering, University of Strathclyde, 204 George Street, Glasgow G1 1XW, UK Shira.Gordon@ars.usda.gov james.windmill@strath.ac.uk.
authors.forename: James F C
authors.initials: JF
authors.lastname: Windmill
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D005260:Female; D006110:Grasshoppers / Q000502:physiology*; D006309:Hearing / Q000502:physiology; D008297:Male; D011984:Sensory Receptor Cells / Q000502:physiology; D012737:Sex Factors; D013016:Sound; D014432:Tympanic Membrane / Q000502:physiology
keywords: Age; Insect; Laser vibrometry; Neurophysiology; Schistocerca gregaria; Sound