The Nervous System

There is so much information about how the nervous system works that it's hard to believe it all fits inside our bodies, much less in a leech.  However, leeches happen to have this really convenient nerve along their backs that's easy to access and test.  In a virtual lab I was able to mess around with the leech's nervous system a bit.

Our bodies are full of neurons.  These neurons are the power behind the neuromuscular junction I talked about earlier.  Action potential starts in the cell body of the neuron and continues as a sort of electrical signal down through the axon, protected by myelin sheaths of fat, and through the axon terminal to become sensation.  Neurons pick up the sensations of what we touch or what touches us and transmits this electrical signal to the brain.  Touching a nerve activates the neuron so it can send the sensations to our brains to be processed.

I made this gif to give a visual of a nerve.  I regret it.

What does this have to do with a leech?  The nerve in the leech could be read with a machine.  Touching the nerve of the leech with the probe stimulated an electric response visible with an oscilloscope.  A micromanipulator helped place electrodes on the neurons.  After positioning the electrode I stimulated the nerve by touching it with a probe, a feather, and forceps.  Each produced a different signal with every cell.  I identified the cells by their signal using the chart below.  The leech lab was a good way to get a good idea of how nerves work without having to by all the 2,000 dollar equipment.

Chart from HHMI Virtual Lab

To wrap up our section on the nervous system our class split into groups and researched different projects relating to the nervous system.  My group and I researched schizophrenia.  I've done projects on schizophrenia before for classes like Psychology and Health.  From a biological perspective there's a lot of different information but it's a bit harder to find since most people only care about the psychological side of schizophrenia.  Regardless of that, I think we faired pretty well.

Schizophrenia on Prezi

Unfortunately I don't know as much about the nervous system as Tim Malouff.  I can't put it all into a huge slide show and teach it for five or more minutes unless I crack jokes and get off track the whole time.  It's an amateur knowledge but I accept it.