The Evaporative Function of Cockroach Hygroreceptors
| Autor: | Wolfgang Kallina, Harald Tichy |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Male
Anatomy and Physiology Sensory Receptor Cells Vapor Pressure Wet-bulb temperature Vapor pressure Evaporation Sensory Physiology lcsh:Medicine Neurophysiology Cockroaches Atmospheric sciences Flow rate Models Biological Neurological System Molecular Cell Biology medicine Animals Relative humidity Sensilla lcsh:Science Biology Multidisciplinary Hygrometer Ecology Chemistry lcsh:R Mechanisms of Signal Transduction Temperature Humidity food and beverages Thermoreceptors humanities Sensory Systems Insects Critical relative humidity Vapors Dryness lcsh:Q Action potentials medicine.symptom Volatilization Saturation (chemistry) Zoology Entomology Research Article Signal Transduction Neuroscience |
| Zdroj: | PLoS ONE PLoS ONE, Vol 8, Iss 1, p e53998 (2013) |
| ISSN: | 1932-6203 |
| Popis: | Insect hygroreceptors associate as antagonistic pairs of a moist cell and a dry cell together with a cold cell in small cuticular sensilla on the antennae. The mechanisms by which the atmospheric humidity stimulates the hygroreceptive cells remain elusive. Three models for humidity transduction have been proposed in which hygroreceptors operate either as mechanical hygrometers, evaporation detectors or psychrometers. Mechanical hygrometers are assumed to respond to the relative humidity, evaporation detectors to the saturation deficit and psychrometers to the temperature depression (the difference between wet-bulb and dry-bulb temperatures). The models refer to different ways of expressing humidity. This also means, however, that at different temperatures these different types of hygroreceptors indicate very different humidity conditions. The present study tested the adequacy of the three models on the cockroach's moist and dry cells by determining whether the specific predictions about the temperature-dependence of the humidity responses are indeed observed. While in previous studies stimulation consisted of rapid step-like humidity changes, here we changed humidity slowly and continuously up and down in a sinusoidal fashion. The low rates of change made it possible to measure instantaneous humidity values based on UV-absorption and to assign these values to the hygroreceptive sensillum. The moist cell fitted neither the mechanical hygrometer nor the evaporation detector model: the temperature dependence of its humidity responses could not be attributed to relative humidity or to saturation deficit, respectively. The psychrometer model, however, was verified by the close relationships of the moist cell's response with the wet-bulb temperature and the dry cell's response with the dry-bulb temperature. Thus, the hygroreceptors respond to evaporation and the resulting cooling due to the wetness or dryness of the air. The drier the ambient air (absolutely) and the higher the temperature, the greater the evaporative temperature depression and the power to desiccate. |
| Databáze: | OpenAIRE |
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