Week 9 – Wiring of the brain
This week was about the wiring and development of the brain, i.e. how the structure of the brain is formed, by e.g. synaptic and developmental plasticity. These are forms of neural plasticity, referring to the growth and reorganization of neural connections in the brain. Developmental plasticity occurs in the early development, childhood and especially in critical periods during childhood. Synaptic plasticity then refers to the selective amplification or weakening of synapses between neurons that reflect the information they store. This is affected by e.g. the threshold of the presynaptic stimulus and the relative concentrations of neurotransmitter molecules. What was really fascinating about both of these types of wiring, is how they occur at a molecular level and form these neural pathways eventually giving rise to consciousness and human abilities. Also the video shown in the lecture really demonstrated how the connections are formed and what drives them.
A key theory related to the wiring of the brain is the Hebbian theory, mostly known for its simplification as “cells that fire together, wire together”. This refers to the fact that the synaptic strength is increased between cells that fire their action potentials simultaneously. An interesting fact of Hebbian theory is that it is widely used in the training of (computational) neural networks. It was dazzling to see that how we humans (the wiring of our brains) somehow resemble machines, or at the very least seem very engineered creations.