Synchronized fireflies: Neuron with light sensor fires every 4^th excitation spike

Two 4-transistor Bionic Blinkenlights (neuromorphic analog integrate-and-fire neurons).
The right neuron has a light dependent resistor in its excitatory path that senses the firing of the left neuron.
When the light is turned off, the right neuron synchronizes its firing rate to the left neuron, firing once every 4 spikes of the left neuron.