Hypothesis: With knowledge of the leeches nervous system and small brain, it will be fairly easy to identify the electrical activity of the leech because the ganglia is large and they all will respond to the same stimuli.
Materials: Leech tank, dissection tray, 20% ethanol, dissecting microscope, mircomanipulator probe, forceps, scissors, dissection pins, leech tongs, Oscilloscope
Procedure: Anesthetize and dissect the leech, Remove the innards and observe the ganglion, Cut out the ganglion window, Isolate one ganglion from the others, Cut the ganglion sinus, Probe and identify the ganglion sensory cells using different stimuli (Feather, Probe, and Forceps), fluorescent dye, and UV light.
Results/Conclusions: One ganglion consists of many cells that are stimulated by different or similar stimuli. Since the leech has such a small system, there are five manageable cell types that can be found. (Cell Types N, T, P, R, and X) Each cell or neuron was found by responding to the feather (weak probing), probe (medium probing), and forceps (strong probing). Some of the cell types responded to all three of the stimuli, but some only responded to a couple stimuli and remained unresponsive. The many responses to a single ganglia portrays the immense amount of stimulation that the entire nervous system of the leech undergoes. Although it is a simple nervous system to work with, it is very complex.
These are the five different cell types that were found within a single ganglia within the leeches nervous system. As the image shows, different stimuli caused similar and differing responses.
Ok so i have this lab also and i have question for you.
ReplyDeleteWhy is it that some nerve cells react to some stimuli and not others?
For example, P cell responds to probe, which is a medium probing, but does not respond to strong probing.