Leech Dissection: Step 8

The blood sinus is cut open using fine scissors, then carefully pulled apart with forceps to expose a ganglion. You can now see individual neurons on the ganglion's dorsal side. Unfortunately, the neurons that respond to touch stimuli are on the ganglion's ventral side, so they are still not visible.

A close-up of a leech ganglion and the surrounding blood sinus.

A second close-up of the leech ganglion. Small scissors are cutting through the blood sinus near the ganglion.

A third close-up of the leech ganglion. The blood sinus around the ganglion has been removed, making the ganglion easier to see. The ganglion is attached to two pairs of nerves, which run perpendicular to the length of the leech and connect to the skin. The ganglion is also attached to a nerve cord, which runs along the length of the leech towards adjacent segments.