Understanding Neuronal Potentials

Local potentials are small, graded electrical changes in neurons. They result from ion movement through channels, and unlike action potentials, they're decremental and reversible.

While local potentials are graded and can summate, action potentials are all-or-nothing events. Local potentials must reach a threshold to trigger an action potential.

An action potential begins at the axon hillock. A sufficient local potential here can depolarize the membrane to a critical threshold, leading to the action potential.

Voltage-gated ion channels are essential for action potentials. They open and close in response to voltage changes, allowing the rapid influx and efflux of ions.

After an action potential, the neuron enters a refractory period. This ensures one-way signal propagation and limits the frequency of nerve impulses, thus preventing overlap.

The human brain generates about 20 watts of power, enough to power a low-wattage LED bulb.