Leech.

The objective of this Neurophysiology Lab on HHMI: was to record electrical activities of neurons while delivering mechanical stimulus, inject fluorescent dyes to neurons for visualization of morphology, and identify neurons based on morphology and response to stimuli. This objective was met by first dissecting the leech all the way to the sinus. After carefully opening the sinus, I located a cell with the electrode and observed the response on the oscilloscope. I then recorded the responses of the cell to a feather stimulus (light), a probe stimulus (medium) and forceps stimulus (high). The last step was to inject dye into the cell so the inside could be visible under UV light. The last objective was met after I was able to identify the type of cell by the response to stimuli and the morphology.

The results you ask? WELL after testing a number of different cells in the sinus, a conclusion could be made. The conclusion you ask? WELL not all cells responded the same to the different stimuli. Therefore, there are different types of neurons in the sinus. There are different types neurons because they all have different functions.

The point of this lab was basically to introduce the nervous system and learn a little bit about the neurons. (and eventually the brain.. woo!)




http://scientopia.org/blogs/scicurious/2011/05/04/science-101-the-neuron/



Just for fun: What else do they use leeches for? Click the picture for more info!