Rhodnius prolixus bug bloodsucking cell responses to infrared radiation in the Differential effects of ambient temperature on warm

• Published in: Journal of neurophysiology Vol. 111; pp. 1341 - 1349
• Main Authors: Tichy, Harald, Zopf, Lydia M., Lazzari, Claudio R.
• Format: Journal Article
• Language: English
• Published: American Physiological Society 2014
• Subjects: Life Sciences
• ISSN: 0022-3077; 1522-1598
• DOI: 10.1152/jn.00716.2013

Differential effects of ambienttemperature on warm cell responses to infrared radiation in the bloodsuckingbug Rhodnius prolixus. J Neurophysiol 111: 1341–1349, 2014.First published January 8, 2014; doi:10.1152/jn.00716.2013.—Thermoreceptorsprovide animals with background information about thethermal environment, which is at least indirectly a prerequisite forthermoregulation and assists bloodsucking insects in the search fortheir host. Recordings from peg-in-pit sensilla and tapered hairs on theantennae of the bug Rhodnius prolixus revealed two physiologicallydifferent types of warm cells. Both types responded more strongly totemperature pulses produced by switching between two air streams atdifferent constant temperatures than to infrared radiation pulses employedin still air. In addition, both warm cells were better able todiscriminate small changes in air temperature than in infrared radiation.As convective and radiant heat determines the discharge, it isimpossible for a single warm cell to signal the nature of the stimulusunequivocally. Individual responses are ambiguous, not with regard totemperature change, but with regard to its source. We argue that thebugs use mechanical flow information to differentiate between pulsesof convective and radiant heat. However, if pulses of radiant heatoccur together with a constant temperature air stream, the mechanicalcues would not allow avoiding ambiguity that convective heat introducesinto radiant heat stimulation. In this situation, the warm cell inthe tapered hairs produced stronger responses than those in thepeg-in-pit sensilla. The reversal in the excitability of the two types ofwarm cells provides a criterion by which to distinguish the combinationof convective and radiant heat from the stimuli presented alone.