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Title:The Behavioral and Neural Bases for Thermoregulation in The Cockroach, Periplaneta Americana (Temperature, Ganglion, Receptor)
Author(s):Murphy, Bernard Francis, Jr.
Department / Program:Physiology and Biophysics
Degree Granting Institution:University of Illinois at Urbana-Champaign
Subject(s):Biology, Animal Physiology
Abstract:The behavioral basis for thermoregulation in the cockroach was investigated by measuring ambient and body temperature selection in cockroaches acclimated to various temperatures and in cockroaches whose primary organs of peripheral thermoreception (antennae and tarsi) had been removed.
The removal of antennae or tarsi did not significantly affect the ambient temperature selection, but the removal of both significantly increased the amount of time cockroaches spent in lethally high temperatures. Mean body temperature was only significantly affected by acclimation to 35 C, removal of peripheral receptors had no affect. Acclimation to 35 C also significantly decreased the mean lowest body temperature selected, and the removal of both organs of peripheral temperatures reception significantly increased the mean highest body temperature selected.
An investigation into the neural basis for thermoregulation involved surveying the temperature sensitivities of neurons in the thoracic ganglia. A statistical paradigm was devised and applied to the responses found in the thoracic ganglia in order to differentiate specific from nonspecific thermosensitivity. A few cells were found in two ganglia that are possible candidates for central temperature receptors.
An effort was made to segregate the effects of antennal thermal stimulation on the firing rates of intrinsically active neurons in the prothoracic ganglion. Antennae were both heated and cooled for short periods of time while recording the temperature of the ganglion and the firing rates of the neurons. Antennal thermal stimulation does seem to affect the relationship of firing rate to absolute temperature in some neurons, but it does not affect the relationship of change in firing rate to change in temperature in any neurons. Only antennal cooling affects cells that demonstrate fit to both absolute and temperature rate regression models. It cannot be unequivocably demonstrated that true thermoregulatory neurons do not receive input from peripheral temperature receptors. It can be concluded that, if an effect is present, it is likely to be a very small one.
Peripheral receptors, therefore, probably serve mainly as rate sensitivie devices for the avoidance of high rates of change in ambient temperature. The major responsibility for thermoregulation lies within a thermosensitive control center in the thoracic ganglia.
Issue Date:1985
Description:351 p.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1985.
Other Identifier(s):(UMI)AAI8511647
Date Available in IDEALS:2014-12-16
Date Deposited:1985

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