Influence of ambient temperature on growth rate of Reissner's fibre in Rana esculenta.

The influences of different environmental temperatures on the growth rate of Reissner's fibre (RF) in Rana esculenta were studied in October. At 24 degrees C about 70% and at 18 degrees C about 45% of the length of RF was renewed in 24 hours. This means that the growth rate of RF at 24 degrees C was about 50% faster than that at 18 degrees C. It strongly indicates that increase in ambient temperature from 18 degrees C to 24 degrees C stimulates the secretory activity of the SCO considerably at least as far as the production of RF is concerned. These results are discussed in view of the hypothesis that RF contributes to the regulation of the composition of the cerebrospinal fluid. In this connection some introductory observations on the capacity of RF to bind certain biogenic amines from the cerebrospinal fluid in Rana esculenta are presented.