NEURAL SPIKE GENERATOR ENTRAINMENT BY REGULARLY SPACED SYNAPTIC INPUT

It has been known for 30 years that the output of a repetitively firin g neuron or pacemaker can be synchronized (locked) to regularly spaced inhibitory or excitatory postsynaptic input potentials. Conditions fo r stable locking have been determined mathematically, demonstrated in computer simulation? and locking has been observed in vivo. We have de veloped a neural spike generator circuit model which exhibits stable l ocking to externally derived simulated inhibitory or excitatory postsy naptic inputs. Conditions for stable 1:1 lock, in which pacemaker outp ut frequency matches that of the periodic input, are derived. These ta ke the form of expressions for stable delay and convergence factor whi ch incorporate known or measurable parameters of the circuit :model. T he expressions have been evaluated and shown to compare satisfactorily with experimental observations of locking by our circuit model.