Responses of the infrared sensilla of Melanophila acuminata (Coleoptera: Buprestidae) to monochromatic infrared stimulation.
The pit organs of the beetle Melanophila acuminata were stimulated with monochromatic infrared radiation using a continuous wave CO overtone infrared laser. Best sensitivity was in the wavelength range 2.8-3.5 micron. In this range a stimulus intensity of 14.7 mW cm(-2) was sufficient to generate single action potentials. At a wavelength of 5 microm receptor performance significantly decreased. An increase in stimulus intensity caused a decrease in response latency and an increase in the number of action potentials elicited. At a given wavelength (3.4 microm) the dynamic amplitude range of action potential responses covered 12 dB. At high stimulus intensities (94.2 mW cm(-2)) a stimulus duration of 4 ms was sufficient to generate one to two action potentials and a stimulus duration of 60 ms already caused response saturation (with up to nine action potentials). In a repetitive stimulus regime distinct receptor potentials were visible up to a frequency of 600 Hz.
Schmitz
H
H
Institut für Zoologie der Rheinischen Friedrich-Wilhelms-Universität Bonn, Germany. h.schmitz@uni-bonn.de
Mürtz
M
M
Bleckmann
H
H
D000200:Action Potentials / Q000502:physiology; D000825:Animal Structures / Q000166:cytology / Q000502:physiology; D000818:Animals; D001517:Coleoptera / Q000502:physiology*; D004594:Electrophysiology / Q000295:instrumentation / Q000379:methods*; D005260:Female; D005425:Flicker Fusion / Q000502:physiology; D007259:Infrared Rays; D007834:Lasers; D008297:Male; D008465:Mechanoreceptors / Q000502:physiology; D009475:Neurons, Afferent / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology