Intrinsic subthreshold oscillations in the membrane potential are a common
property of many neurons in the peripheral and central nervous system. When
such oscillations are combined with noise, interesting signal encoding and
neuromodulatory properties are obtained which allow, for example, sensitiv
ity adjustment or differential encoding of stimuli. Here we demonstrate tha
t a noisy Hodgkin/Huxley-model for subthreshold oscillations, when tuned to
maximum sensitivity, can be significantly modulated by even minor physiolo
gical changes in the oscillation parameters amplitude or frequency. Given t
he ubiquity of subthreshold oscillating neurons, it can be assumed that the
se findings reflect principle encoding properties which are relevant for an
understanding of sensitivity and neuromodulation in peripheral and central
neurons. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.