This blog exists to give you a glimpse into the mind of a Macalester College student enrolled in the Behavioral Neuroscience class taught by Professor Wiertelak. The structure of the blog breaks down the experience by week although this first post technically covers the first two weeks.
This first section is just a review to get the entire class on a somewhat level playing field allowing us to effectively learn together. As a Neuroscience Studies major in my senior year it was almost entirely a review for me but it was great to get some clarity on topics I had learned about before but didn’t completely understand. Top among those is how a neuron changes a chemical signal into an electromagnetic signal and how that signal moves along the axon. I knew this very broadly before but now I am much more confident in that information.
The signal being moved down the axon of a neuron is called an action potential. The unexcited state of a neuron is called the resting potential. The resting potential of a neuron is roughly -70 mV however it is not a static state. The voltage of the neuron changes constantly. If the voltage reaches the threshold of excitation, which is about -65 mV, then an action potential occurs. Once that section of the neuron reaches the threshold the voltage gated Na+ ion channels in that area open and Na+flows into the cell causing the cell to depolarize to 0 mV and then continue to rise to about +40 mV which repolarizes the cell. At +40 mV Na+ reaches equilibrium. K+ ion channels have been open but the effects of this aren’t noticeable until now. At this point K+ flows out of the cell down its concentration gradient causing the cell to depolarize to 0 mV and then repolarize back to -70 mV. However, it doesn’t stop there. The voltage continues to drop a little bit further below -70 mV which is called hyperpolarization. The voltage then comes back to -70 mV, or the resting potential, and is now ready to start the process over again for the next signal to come its way.
Behavioral Neuroscience at Macalester 