Click on image to view larger version.

Fig. 7. Mechanical stimulation of the ovotestis induces an efferent reflex response
from the CNS that travels into both the pericardial (PC) and ovotestis
branches of the intestinal nerve. (A) Traces recorded at four positions on the
intestinal nerve (see Fig. 1).
Action potentials conducted to and from the ovotestis were recorded by two
electrodes (SV-P and SV-D) placed on the nerve as it passes over the seminal
vesicle; afferent vs efferent spikes were discriminated using timing
differences at these two electrodes. The arrowhead indicates stimulation of
the ovotestis with a wooden applicator stick (3 s duration). Note that an
elevated level of activity is recorded at all electrodes in the 10 min period
following the stimulus. (B) Raster plot showing the timing of afferent and
efferent spikes recorded at seminal vesicle electrodes as well as efferent
activity recorded at the pericardial electrode. Time 0 indicates the onset of
tactile stimulation.