The kinetics of homosynaptic short-term depression in cell RPa3 of Helix pomatia depends upon the level of activity prior to depression.
1. Following synaptic rest periods of 2 min, recovery from EPSP depression was dominated by a monoexponential phase completed within 2 min. After rest periods of 6 min, a two-phased recovery occurred: a transient phase followed by a slow phase lasting 10 min. 2. The shift of recovery kinetics was associated with a change of the time course of depression: following rest periods of 2, 6 and 12 min, EPSP trains of 1/10 Hz gave three different depressions. 3. The change of recovery inverted a logarithmic proportionality between frequency of EPSPs and degree of depression to an inverse relation.
Zoophysiological Laboratory B, August Krogh Institute, University of Copenhagen, Denmark.
G R
GR
Christoffersen
D000818:Animals; D005073:Evoked Potentials, Somatosensory; D006372:Helix, Snails / Q000166:cytology; D007700:Kinetics; D013569:Synapses / Q000502:physiology*