Ref ID : 4331
Matsuoka Tatsuomi, Imanaka Takanobu, Arita Tomikazu, and Taneda Koji; Localization of Thermoreceptor Systems that Induce Step-Up and Step-Down Thermophobic Responses and Switching in the Dominance of These Systems in Blepharisma. J.Protozool. 38(4):335-338, 1991
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The distribution of thermoreceptor systems that initiate step-up and step-down thermophobic responses in bisected cells of Blepharisma was examined. Anterior cell fragments responded by ciliary reversal to a step-down in temperature and by repression of spontaneous ciliary reversal to a step-up. Posterior fragments responded by ciliary reversal to a step-up in thermal stimulation and by repression of spontaneous ciliary reversal in response to step-down stimulation. Results indicate that two kinds of thermoreceptor systems exist in the anterior half of each cell; one is responsible for ciliary reversal induced by step-down stimulation, and the other is responsible for repression of the ciliary reversal caused by step-up thermal stimulation. Likewise, there are also two kinds of thermoreceptor systems in the posterior half of the cell; one is responsible for ciliary reversal in response to a step-up in temperature, and the other is responsible for the repression of ciliary reversal on a step-down in thermal stimulation. Below about 27 degrees C, intact cells showed ciliary reversal only when a step-down in thermal stimulation occurred, while above about 27 degrees C cells only responded to a step-up in thermal stimulation. At about 27 degrees C there was a switch in the dominant response from the anterior to the posterior half of an individual cell.