  Recently spike timing dependent plasticity was observed in inhibitory synapse
in the layer II of entorhinal cortex. The rule provides an interesting zero in
the region of $\Delta t=t_{post}-t_{pre}=0$ and in addition the dynamic range
of the rule lie in gamma frequency band. We propose a robust mechanism based on
this observed synaptic plasticity rule for inhibitory synapses for two mutually
coupled interneurons to phase lock in synchrony in the presence of intrisic
heterogeneity in firing. We study the stability of the phase locked solution by
defining a map for spike times dependent on the phase response curve for the
coupled neurons. Finally we present results on robustness of synchronization in
the presence of noise.
