Our brains are like a dense forest – a complex, seemingly impenetrable terrain of interacting neurons that mediates cognition and behavior. The great challenge is to uncover its mysteries, that is, to find out how the neurons are structured and mutually connected. How close are we to that goal?
In general, the exchange of information between the billions of neurons that make up the neuronal forest takes place through two types of highly specialized structures: chemical synapses (the majority) and so-called gap junctions (a substrate of one class of electrical synapse). Chemical synaptic transmission involves the release of specific molecules, neurotransmitters, which diffuse through the intercellular space and interact with specific receptors located on an adjacent neuron.