Physiological role of a slow, voltage-sensitive, synaptic response mediated by an identified serotonin-containing neurone.

In Helix, activation of an identified serotonin-containing neurone produces a slow, markedly voltage-sensitive, depolarizing synaptic potential in another identified neurone, the A neurone. Accommodation of impulse activity in the A neurone observed with repetitive applied constant-amplitude pulses is markedly reduced by activating the serotonin neurone. Activation of the serotonin neurone also prolongs the duration of the A neurone action potential.