Neurons are constantly bombarded by synaptic input that causes increased membrane conductance, tonic depolarization, and noisy fluctuations in membrane potential and ion gradients. We conducted a number of experimental and computational studies showing how synaptic noise and associated ionic mechanisms dramatically affect how neurons process input, generate action potentials and integrate information. Our findings include the following.
1) Demonstration that the ability of neurons to achieve gain control of firing rate is critically dependent on membrane noise produced by on-going synaptic input bombarding the cell.
2) Demonstration that neurons can switch from integrators to resonators when bombarded by synaptic activity comparable to that seen in intact networks (in vivo).
3) Identification of fundamental biophysical principles underlying different mechanisms of spike-initiation, critical for understanding the biophysics of neural coding.