Serotonin potentiates presynaptic calcium currents and transmitter release at cortical synapses

Synaptic strength is dynamically modulated not only by activity-dependent processes but also by neuromodulators. These modulators can enhance or depress synaptic transmission and play essential roles in circuit function and in the pathophysiology of psychiatric disorders. Although neuromodulation is functionally important in vivo, the underlying cellular mechanisms—particularly at the presynaptic site—remain poorly understood in mammalian synapses because of the difficulty in obtaining direct ac