Week 2 – The neuronal membrane at rest and action potential

This week’s topic on the structure and operation of the human brain course was centered around the structure and electrical properties of the neuronal membrane at rest, and the generation and conduction of action potentials. The exercise set of the week greatly supported our learning as it had us think through the phases of action potentials and their conduction within axons. Furthermore, we derived the Nernst equation from the Boltzmann distribution, which helped us understand the relation between resting membrane potential and the concentration gradient across the neuronal membrane.

The book is very well written and greatly supported our learning. Even though most of the material this week was already somewhat familiar to me from my previous studies, I still found the topic interesting, and this was a good recap, providing a little more detailed information. The “special interest” boxes were especially interesting. Having already studied basic biophysics, it was interesting to read about the implications of the resting membrane potential and its role in the generation and conduction of action potentials.

Strikingly, it was fascinating to already learn about the mechanisms of many diseases and how seemingly small anomalies in the fundamental neuronal processes and structures can lead to severe illness and even death.

Special interest was aroused by the topic about local anesthesia. It was new information that local anesthetics effect first on smaller axons. After reading the chapter, the reason for that was clear: the axonal size has important role in influencing the axonal excitability because the depolarization for reaching action potential required by the smaller axons are way greater than on the bigger axons. And as it was said on the chapter, local antesthetics blocks action potentials only temporarily, so immediately a question arose: what factors effect on this duration and how the drug is removed from their target protein?