Fundamentals of Neuroscience, Part 2: Neurons and Networks

Neurons in isolation are fascinating and complex, but the real magic of neuroscience becomes manifest when we consider how neurons interact with one another. In this module, we examine how neurons pass signals to one another, and we explore how complex dynamics can result from even small numbers of neurons arranged in relatively simple circuits.

Lesson1: The Synapse
The junctions between neurons, called synapses, allow information to pass from one neuron to another. In lesson 1 “The Synapse,” we explore what synapses are made of, and how they work.

Lesson 2: Excitation & Inhibition
Synapses can be grouped into two categories: synapses that increase the activity of the postsynaptic neuron are called excitatory synapses, while those that decrease its activity are called inhibitory synapses. In lesson 2 “Excitation & Inhibition,” we discuss the main differences between excitatory and inhibitory synapses.

Lesson 3: Small Circuits
Neurons combine information from many synapses at once in a process known as synaptic integration. In lesson 3 “Small Circuits,” we explore how a neuron integrates information from multiple synapses over time to allow complex signaling.

Lesson 4: Neuromodulation
How many components are there in a synapse? You may think that the answer is simple: two, the presynaptic and the postsynaptic terminals. In lesson 4 “Neuromodulation,” we’ll see that this is not entirely true: the strength of many synapses is directly influenced by a third neuron, in a process called neuromodulation.

Lesson 5: Potentiation & Depression
One of the most amazing properties of the nervous system is its ability to adapt and change in the face of a changing environment, a phenomenon called "neuronal plasticity." Lesson 5, “Potentiation and Depression,” focuses on how neuronal plasticity occurs in the brain, and how it shapes the way we think and behave.