Fig. 4. Spike bursting of mDP in normal spermatophore extrusion. (A) The discharge pattern of mDP (top trace) around spermatophore extrusion induced by genital stimulation, which was started at the inverted triangle and stopped at the first bursting of mDP. mDP did not respond to the first 4.3 s, but then exhibited a strong burst (arrow), and gradually changed its discharge into a rhythmic burst after the spermatophore transfer phase (horizontal thick line). The lower trace shows the movement of the phallic complex. Each upward deflection after the spermatophore transfer phase (dots) indicates the movement of the phallic complex. (B) Discharge pattern of mDP after spermatophore extrusion. The rhythmic bursting did not stop unless the female stimulus was given. Numbers on the right indicate time (min) after spermatophore extrusion.