Module 10: Figure oxytocin neuron synchronization
Synchronization of action potential bursts in oxytocin neurons.
The ability of the oxytocin neurons to generate bursts of action potential depends on the dendritic release of oxytocin that then sets up a dendrodendritic communication system. The upper panel shows five oxytocin neurons lined up next to each other. Neuron 3 functions as a pacemaker in that it spontaneously releases oxytocin (OT) from its dendrites and it also begins to initiate a burst of action potentials that trigger release of OT from the nerve endings. The middle panel shows how the OT from the dendrites of neuron 3 diffuses across to the neighbouring cells (neurons 2 and 4) to trigger a similar series of events (green arrows): dendritic release of OT, burst initiation and OT release from the nerve endings. This positive-feedback mechanism then sets up a regenerative mechanism that enables all the neurons to fire in close synchrony with each other. The dashed arrows show how the wave of excitation, which is reflected in the initiation of the bursts, spreads from the pacemaker neuron 3 to the neighbouring neurons.