How Do Leeches Feel?

Why is there a leech in my lab? In this lab, you are going to investigate the nervous system of the leech. You will use electrodes to record how individual neurons in the leech respond to different kinds of touch stimuli. These neurons are large, making it relatively easy to record their electrical signals. By recording signals from different types of neurons, you can map how the leech's nervous system represents touch sensations through labelled lines.

Three leeches are in a clear bottle of water. The leeches have long, dark, worm-like bodies. One leech has its tail sucker pressed against the front of the bottle.

The lab is divided into two sections:

In Leech Dissection, you will observe a procedure that isolates part of the leech's nervous system to make the neurons accessible for electrodes.
In Probe & Identify, you will place electrodes in different neurons to explore their electrical responses to touch stimuli. You will also use fluorescent dye to observe each neuron's anatomy.

To begin, press the "Leech Dissection" or "Probe & Identify" links above. You can also press the "Background" button at any time to access supporting information and a glossary.