We enjoyed an afternoon in an Advanced Physiology class at Vancouver’s HeLa High this afternoon, a STEM-focused public school named after Henrietta Lacks…
We began by reviewing the electro-chemical nature of information flow in the nervous system. Bill went over resting and action potentials, while Jeff drew a cell membrane and various gated channels on the board.
Below is a sculptural interpretation of a neuron’s membrane (which is primarily a phospholipid bilayer), built by Portland, Oregon metal artist Matt Cartwright)…
We then delved into the individual neurotransmitters, which the students had studied in advance. We began with the first identified classical neurotransmitter, discovered by Austrian scientist Otto Loewi, acetylcholine (ACh). We discussed its role at the neuromuscular junction, where its release provokes muscle contraction.
We explained the effect of nerve gases and toxins that inactivate the neuromuscular ACh, including pesticides based on nicotine, which have lately killed tens of thousands of bees in the Northwest. Portland has banned the sale of these insecticides; however these chemicals remain legal around the region, and end up poisoning pollen that bees feed to their fragile young. If you see pesticides that contain “neonicotinoids,” you can help more bees survive by leaving them on Fred Meyer shelves. The Xerxes Society, based in Portland, has excellent resources on this topic if you’d like to learn more…
We also talked about the importance of ACh in the parasympathetic nervous system, where it reduces heart rate and promotes energy conservation, and its central nervous system (CNS) role in effective memory and cognition. Most FDA-approved drugs for Alzheimers disease boost CNS availability of acetylcholine, potentially increasing the “signal” from remaining ACh-releasing (“cholinergic”) neurons in the brain. HeLa students knew all about a major target of these CNS cholinergic neurons, the hippocampus, and the critical role of this structure in episodic memory…
Brianna Jacobs from PSU then introduced dopamine (DA), and its essential role in motivated behavior, and movement. She talked about how some drugs, like alcohol, or cocaine, can hijack DA networks and lead to dependence, and how degeneration of one of two primary brainstem sources of dopamine projections (the substantia nigra) can cause a common movement disorder known as Parkinson’s disease.
Chelsey Anderson Taylor from WSU Vancouver talked about norepinephrine, and we enjoyed a lively exchange about stimulants like Ritalin and Adderall, along with other non-drug ways (including adequate sleep, better nutrition, and less stress) to address the symptoms of attention deficit hyperactivity disorder (ADHD). Gaile Parker from PSU brought up serotonin, and its role in psychological health and mood. And Veronica Robertson from WSUV discussed GABA, and glutamate…
We covered a lot of ground today (these topics often take several weeks at the college level!). Many thanks to HeLa teacher Nancy Keller for welcoming us to her class… 🙂