biological bases of behavior: neurotransmitters

neuron

a nerve cell; the basic building block of the nervous system

cell body

the part of a neuron that contains the nucleus; the cell's life-support center

dendrites

a neuron's bushy, branching extensions that receive messages and conduct impulses toward the cell body

axon

the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands

myelin sheath

A layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next.

glial cells

cells in the nervous system that support, nourish, and protect neurons

action potential

a neural impulse; a brief electrical charge that travels down an axon

threshold

the level of stimulation required to trigger a neural impulse

refractory period

the time following an action potential during which a new action potential cannot be initiated

all-or-none response

a neuron's reaction of either firing (with a full-strength response) or not firing.

synapse

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron

neurotransmitters

chemical messengers that cross the synaptic gap between neurons

reuptake

a neurotransmitter's reabsorption by the sending neuron

endorphins

"morphine within"--natural, opiatelike neurotransmitters linked to pain control and to pleasure.

agonist

a molecule that increases a neurotransmitter's action

antagonist

a molecule that inhibits or blocks a neurotransmitter's action

nervous system

the body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems

central nervous system

brain and spinal cord

Acetylcholine

a neurotransmitter that plays a role in memory, learning, attention, arousal and involuntary muscle movement

Dopamine

a neurotransmitter crucial for rewards and movements, motivation, attention, learning, and emotions

Serotonin

a neural transmitter that contributes to feelings of well-being and happiness

Norepinephrine

neurotransmitter involved in stress response (fight-or-flight)

GABA (gamma-aminobutyric acid)

calms the nervous system and help your nerves process sensory input

Glutamate

Boosts brain activity and plays a vital role in learning, forming and retrieving memories

Endorphins

Body’s natural pain killers and pleasure inducing neurotransmitters