As many of my readers know, I am a graduate student pursuing a PhD in molecular neuroscience. For those that think I'm crazy, maybe I am, but I hope you will feel a little crazy too after hearing a bit more about why I've chosen this path...
Unless you are a student of neurophysiology or unlucky enough to have epilepsy you probably have never heard of ion channels. Ion channels are the proteins that control the “electricity” of your nervous system. Just like the components in an electrical circuit (resistors, transistors, capacitors, etc.), ion channels are tiny elements in the circuitry of your brain. Ion channels switch on and off in precise ways to control when and where bioelectricity flows in your brain (and body).
I didn’t know ion channels existed until 2012 when I took a class in the Hendrix College Psychology department titled “Sensation and Perception.” It was here that I learned how my interaction with the world around me - my sense of taste, smell, vision, etc. - is possible because of the way stimuli in the world influence the bioelectricity in my brain. For example, in your nose there are millions of cells that are dedicated to sensing the smell molecules in the air you breathe. Freshly baked cookie smells trigger one set of those cells and farts trigger another, but in both cases, odor molecules act as a switch that turns on the ion channels in the cells. By switching on the ion channels, current flow through the nose cells is altered. This small change that starts with the ion channels in your nose gets propagated across the brain, and eventually leads to you think either “yum” or “ew”. It’s like the nose is just a tiny corner of the circuit of your brain, and changing a component in the nose circuit changes the way electricity flows across the whole board!
The same principle is not only true for each of the sensory modalities, but also for even more complex phenomena, like learning. It’s probably intuitive to think that when I learn a new skill there are some changes in my brain that go along with it. Some of those changes are occurring at the single neuron level, and perhaps even the single ion channel level. Just as exchanging a 10kOhm resistor for a 100kOhm resistor on a PCB would alter the output of the circuit, our bodies are constantly adding/replacing/removing/adjusting the ion channels in our neurological circuits so that the outputs of our nervous system are appropriate for existing in our world. This is what we call learning.
It is these amazing feats of biology that drew me to study molecular neuroscience and the nuances of bioelectricity. Even after 5 years studying how the nervous system works at this scale, it is still difficult to grasp the complexity and precision with which our minds and bodies work. I don’t know that I or anyone will ever have complete understanding, but I know that there are rewards in stumbling across even the smallest answers.
Further reading
Eisenberg, B. (2005) Living Transistors: a Physicist's View of Ion Channels. arXiv:q-bio/0506016v2 [q-bio.BM]
Gasque, G., Labarca, P., Delgado, R. and Darszon, A. (2006) Bridging behavior and physiology: Ion-channel perspective on mushroom body-dependent olfactory learning and memory in Drosophila. J. Cell. Physiol., 209:1046-1053. doi:10.1002/jcp.20764
Eisenberg, B. (2005) Living Transistors: a Physicist's View of Ion Channels. arXiv:q-bio/0506016v2 [q-bio.BM]
Gasque, G., Labarca, P., Delgado, R. and Darszon, A. (2006) Bridging behavior and physiology: Ion-channel perspective on mushroom body-dependent olfactory learning and memory in Drosophila. J. Cell. Physiol., 209:1046-1053. doi:10.1002/jcp.20764
Liu, M. et al. (2016) Acid-sensing ion channel 1a contributes to hippocampal LTP inducibility through multiple mechanisms. Sci. Rep., 6:23350. doi:10.1038/srep23350
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