Online Lab Five -- HHMI Virtual Neurophysiology Lab

Katie Meyers

Online Lab Five – HHMI Virtual Neurophysiology Lab

Here is my first screen shot that shows the manipulator with the oscillope trace.

Here is my ultra-violet image of the neuron with dye in it showing it has the shape of a sensory neuron.

1. What is the electrode measuring?

The electrode is measuring the activity of the neuron(s).

2. Why use leeches in neurophysiology experiments?

Their nerve cords have very large and easily accessible neurons on them, making them easier to dissect and experiment on.

3. What is the difference between a sensory and a motor neuron?

A sensory neuron conducts impulses from an organ to the spinal cord and brain. A motor neuron does just the opposite; it conducts impulses from the brain and spinal cord to a muscle or gland.

4. Do you think a leech experiences pain? What is pain?

Pain is the “hurt or suffering of the body or mind” (from http://dictionary.reference.com/browse/pain). As long as leeches have brains of some sort (I am assuming they do, as they are living creatures that act of their own volition), I would say that leeches do feel pain, since this experiment shows that leeches have nerve cords and (large) neurons, which will transmit signals to their brain, thereby making them aware of physical pain.

5. What were the two most interesting things about doing this lab?

I have never dissected before, and I am also easily unsettled at the thought of doing so. However, this lab gave me a relatively realistic dissection experience, without the gore or trying to physically cut something open. Also, as this was my first time dissecting, I was grateful that they did not make it as difficult as it could have been in reality (e.g. they make the incisions without you having to worry whether or not you cut too deep or too shallow). I also really enjoyed figuring out what types of neuron readings I was picking up, and how to tell the types of each neuron I was examining. It was an informative, not very hard, and enjoyable experience.

6. Anything you found confusing or didn't like about the lab?

During the dissection, I did not click the exact place on the screen I was supposed to once or twice. However, I do not see that as the lab’s fault, since the directions were clear. It was just me not being as careful as I should have been. Otherwise, I have no complaints about this lab assignment.