Implanted electrode recordings from a praying mantis auditory interneuron during flying bat attacks.
Using an implanted electrode, we recorded the responses from the ultrasound-sensitive mantis interneuron 501-T3 during flying bat attacks in a large flight room where the mantis served as the target. 501-T3 responds to each vocalization emitted with multi-spike bursts when pulse repetition rates (PRRs) are below 55 pulses x s(-1). As PRR increases and pulse durations fall below 3 ms, 501-T3 ceases burst activity. On average, spike bursts cease 272 ms before contact (when the bat is 73 cm away from the preparation). The timing of cessation of activity in 501-T3 is similar to the latency for the diving portion of the response of the mantid (242 ms). Experiments using vocalizing stationary bats confirm that 501-T3 responds more reliably to longer pulse durations (> or =3 ms) when intensities are below 90 dB pe SPL. The cessation of 501-T3 activity is probably due both to the increasing PRR and to the decreasing pulse duration that occur in the terminal buzz phase of a bat attack. 501-T3 may be actively shut off at high PRRs and/or intensities to protect the interneuron from habituation while the mantis performs an escape response. The cessation of 501-T3 activity is consistent with the lack of a very late ultrasound-mediated evasive response by the mantis. However, cessation of 501-T3 activity may allow a true 'last-chance' response to be mediated by other neural systems.
Triblehorn
Jeffrey D
JD
Department of Psychology, University of Maryland, College Park, MD 20742-4411, USA. jtriblehorn@psyc.umd.edu
Yager
David D
DD
D000818:Animals; D002685:Chiroptera / Q000502:physiology*; D004455:Echolocation; D004567:Electrodes, Implanted; D004924:Escape Reaction; D005260:Female; D006185:Habituation, Psychophysiologic; D007395:Interneurons / Q000502:physiology*; D008297:Male; D020050:Mantodea / Q000502:physiology*; D011235:Predatory Behavior; D014465:Ultrasonics; D014828:Vocalization, Animal