Core overview
A typical neuron has a cell body, dendrites that collect input, and an axon that can carry output over long distances. Resting and active electrical states arise from the movement of ions across the membrane. When excitation crosses a threshold, many neurons generate an action potential: a brief, travelling signal.
Synapses may be chemical or electrical. Chemical synapses release neurotransmitters into a narrow gap; receptors on the receiving cell convert that message into electrical or biochemical changes. Electrical synapses allow direct current flow and often support rapid synchrony.
How it works
At chemical synapses, incoming signals influence whether the postsynaptic neuron becomes more or less likely to fire. Summation of many inputs determines output. Modulatory systems can adjust gain, attention, and readiness across circuits.
Synaptic plasticity refers to activity-dependent changes in synaptic strength. It is a central idea for learning and memory, though specific mechanisms vary by brain region and task. Research distinguishes short-term changes from longer-lasting remodeling of connections.
Why it matters
Concepts like action potentials and synaptic transmission connect classroom models to medications that target neurotransmitter systems, to rehabilitation after nerve injury, and to debates about brain training without overstating what is proven. They also frame realistic expectations: behaviour arises from many neurons working together.