Synaptic basis of a sub-second representation of time

Abstract

AbstractTemporal sequences of neural activity are essential for driving well-timed behaviors, but the underlying cellular and circuit mechanisms remain elusive. We leveraged the well-defined architecture of the cerebellum, a brain region known to support temporally precise actions, to explore theoretically whether the experimentally observed diversity of short-term synaptic plasticity (STP) at the input layer could generate neural dynamics sufficient for subsecond temporal learning. Simulated synaptic input generated a diverse set of transient, firing patterns in granule cells (GCs) that provided a temporal basis set for learning precisely timed pauses of Purkinje cell activity associated with delayed eyelid conditioning and Bayesian interval estimation. The learning performance across time intervals was influenced by the temporal bandwidth of the GC basis, which was determined by the input layer synaptic properties. The ubiquity of STP throughout the brain positions it as a general, tunable cellular mechanism for sculpting neural dynamics and fine-tuning behavior.