Brain and Behavior Vocabulary

Dendrites

Branch-like extensions of a neuron that receive chemical signals and incoming messages from other cells.

Cell Body

The part of a neuron containing the nucleus and cell machinery that maintains basic cellular life function.

Axon

The long fiber of a neuron that generates action potentials and sends outgoing signals away from the cell body toward other neurons.

Action Potential

A neural impulse that requires activation above a resting threshold to produce an all-or-none electrical response along the axon.

All or None Response

The principle that a neuron's action potential always fires with constant intensity whenever stimulation crosses the resting threshold, firing more frequently given greater stimulation.

Synapse

The junction where axon terminals release chemical messages across a synaptic gap to be picked up by dendrites of another neuron.

Synaptic Gap

The physical space between the axon terminal knob and the membrane of receptor cells across which neurotransmitters diffuse.

Acetylcholine (ACh)

A neurotransmitter that enables muscle action, learning, and memory; a breakdown in ACh-producing neurons marks Alzheimer's disease.

Dopamine

A neurotransmitter influencing movement, learning, attention, and emotion; excess receptor activity is linked to schizophrenia, while dopamine loss