Extreme degeneracy of inputs in firing a neuron leads to loss of information when neuronal firing is examined

Abstract

Possible combinations of inputs of the order of 10¹⁰⁰ can fire (axonal spike or action potential) a neuron that has nearly 10⁴ inputs (dendritic spines). This extreme degeneracy of inputs that can fire a neuron involves significant loss of information when examination is limited to neuronal firing. Excitatory postsynaptic potentials (EPSPs) propagating from remote locations on the dendritic tree attenuate as they arrive at the axon hillock depending on the distance they propagate. Moreover, some EPSPs from remote locations will not even reach the axonal hillock. In this context, an operational mechanism at the location of origin of these EPSPs is necessary to preserve information for efficient storage. A similar mechanism is also expected at the location of origin of EPSPs generating dendritic spikes.