1967a, b), driver potentials are relatively slow, sustained, regenerative depolarizations that may arise from a gradual pacemaker potential or be evoked by a depolarization, such as an excitatory synaptic potential (or an applied depolarizing stimulus) (Fig.
Intracellular recordings from the small, posterior neurons have consistently shown a slowly depolarizing pacemaker potential that develops after the post-burst hyperpolarization and leads to the initiation of the next burst (Fig.
Autonomous rhythmicity: stretch responsiveness and pacemaker potentials
The question raised by the contrast in behavior of unstretched hearts and isolated ganglia is whether stretchinduced depolarization of dendrites and collateral processes normally induces bursting activity of the ganglion, while in isolated ganglia, the pacemaker potentials that functionally replace this stretch response in fact represent an injury current.
One of the ionic mechanisms giving rise to pacemaker potentials is hyperpolarization-activated cationic current, now generally referred to as [I.
Electrotonic coupling links all cells of the ganglion and passes slowly changing potentials such as stretch-induced or pacemaker potentials and DPs, and these can continue to recur synchronously and rhythmically when impulse propagation has been eliminated with TTX.