Intrinsic representational drift from predictive excitatory-inhibitory plasticity

Neural representations drift gradually over time even under stable environmental conditions, but the synaptic mechanisms driving this drift remain unclear. Here we show that representational drift can arise intrinsically from predictive synaptic plasticity in spiking excitatory-inhibitory networks. During repeated exposure to unchanged input patterns, individual neurons gradually changed their preferred pattern while ensemble-level coding remained stable. These changes in preference were preceded by a weakening of the net excitatory-inhibitory drive supporting the current preference relative to competing patterns, and this relative drive predicted changes on the following trial. Extending the model to hippocampal place coding reproduced experience-dependent tuning-curve drift in CA1, including the dissociation between elapsed time and intervening exposure. At the population level, drift was expressed as coordinated rotation and translation of neural state space. Thus, representational drift can emerge as an intrinsic consequence of predictive E/I plasticity that maintains balanced, selective population codes.