Biophysical basis of neural memory

Abstract

The model of neural membrane describes interaction of gating charges (GC), their conformational mobility and immobilization during excitation. Volt-conformational and current-voltage characteristic (VCC and CVC) of the membrane are analytically derived. Inactivation is shown to change these characteristics during excitation; this is caused by GC immobilization, instead of the contrary. VCC and CVC have hysteretic properties. Due to them electroexcitable units of the somato-dendritic (SD) membrane arrange a memory medium well adapted to record, keep and reconstruct afferent information. GC immobilization underlies consolidation of memory traces. The theory of quasi-holographic associative memory is constructed where role of memory medium is carried out by synaptic addressed units of electroexcitable mosaics of SD-membranes. Small changes of membrane potential (slow potentials) select modes of such memory: if the working point on VCC is displaced inside the hysteretic loop, then the neuron is in writing mode, if outside then in a reading mode. Current distribution of slow potentials shares neuron population on writing, reading and intermediate sets (short-term memory), they are in relative dynamic (metabolic dependent) balance.