| Abstract: | Unit activity was recorded extracellularly from the pontomedullary reticular nuclei of kittens aged 1–5 and 15–30 days, immobilized with diplacin. Properties of neurons located in the medial and lateral zones were compared. As regards the amplitude of spike potentials and types of spontaneous and evoked activity, the cells of the two groups were shown to differ. Tetanic stimulation with a frequency of 300 Hz caused a decrease in the medial zone but an increase in the lateral zone in the number of responding units compared with responses to single stimulation. In neurons of the medial zone intensification of spontaneous activity in the interval between stimuli was more marked and continued after the end of stimulation for a long time. It is suggested that units whose activity is recorded in the medial and lateral zones are mainly giant densely branched and reticular sparsely branched neurons respectively. The difference in the characteristics of activity is connected with the geometry of the dendrites and the foci of their maximal branching.Institute of Higher Nervous Activity and Neurophysiology, Academy of Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 14, No. 2, pp. 140–148, March–April, 1982. |
