Serotonin enhances synaptic potential

Serotonin is a molecule that enhances synaptic activity. This can be seen by comparing the size of synaptic potentials before and after application of serotonin to the medium in which the cells are cultured.

After serotonin application, the synaptic potential becomes markedly larger. When synaptic potentials are larger, fewer are needed to trigger an action potential.

Electrical activity graph shows serotonin enhances synaptic potential.
Following an action potential spike, a low peak labeled after serotonin is 3 to 4 times taller than another trace labeled before serotonin.

Synaptic potentials before and after serotonin

Electrical activity of the sensory neuron