Neurotransmitter Lab


The purpose of the lab is to learn about muscle physiology through EMGs. Also, we want to gain an understanding of neuron and muscle communication and listen to the electrical impulses of muscles at rest and during contraction.


To be able to move our muscles, neurons from our mortor cortex travel to our spinal cord, ten they synapse. These motor neurons then synapse with muscles to make a motor unit. Muscle fibers are essential because they help the muscles move. A muscle fiber is a cell that can change its shape. For example, our bicep muscle has 1000s of muscle fibers, where as a smaller muscle like our eyeball muscles, only use about 10 muscle fibers. Motor neurons fire action potential, which causes a release of the chemical acetylcholine at the synapse between the neuron and the muscle. The acetylcholine then causes changes in the electrical potential of the muscle. The action potential travels across the muscle, which then causes voltage at the calcium channels to open. This allows the muscle to contract.

Olivia hooking up the Muscle SpikerBox


  1. Remove the sticky backing off of the two electrodes, then place the electrodes on the two sides of your bicep.
  2. Hook up the Muscle SpikeBox leads (2 red clips) to the surface electrodes on your bicep.
  3. Place an electrode on the back of your hand. Then, clip the black clip to this electrode.
  4. Turn on the Muscle SpikerBox and listen for changes in activity. Try flexing your muscles.
  5. Plug in your smartphone or computer.
  6. Pick up something heavy or do a couple of pushups, listen to the change.
Meaghan getting electrodes stuck onto her arm

Unfortunately, the apps were not working correctly. So, we were not able to gain any reliable data for this lab. While we were not able to get data, we can still answer a few questions:

  • We use our tricep and bicep muscles to wave.
  • The antagonist muscle still shows spikes because it still have some muscle fiber movement, just not as much as the other muscles.
  • There are two different types of spikes. antagonist and agonist. Antagonist are the smaller more relaxed muscle spikes, while the agonist spikes are of the muscle that is mainly being used.

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