Quantal analysis: how are neurotransmitters released
On week 2, I realized that my students were utterly confused about a very important topic that had been presented in class: quantal analysis. To help students understand this important concept, I created the following worksheet to work through during my sections on week 3. This worksheet was so popular not only in my section, but in the section of other teaching fellows that I subsequently crafted worksheets for each following week. My goal was to take students beyond understanding the class material, to be able to solve related problems. Through basic exercises like fill-in the blank to more complex short answer questions and analyses of figures from real scientific papers, I encouraged students to learn actively and think conceptually.
Quantal release is a fascinating topic in neurobiology, explored mainly by B. Katz and colleagues in the 1950’s – 1970’s. They were asking how chemical messengers called neurotransmitters are released at the intersection of neurons (synapses). Through statistical analysis of electrophysiological recordings made from neuromuscular junctions, they found that neurotransmitters are released in multi-molecular packets or “quanta”. High-resolution electron microscopy images corroborated this quantal model by demonstrating that synaptic vesicles in the nerve terminal contain packets of neurotransmitters.