Unit 3: How do our neurons communicate with each other?

Postsynaptic potentials

small changes in voltage (membrane potential) due to the binding of neurotransmitter.

Synaptic vesicles

small spherical membranes that store neurotransmitters and release them into the synaptic cleft

Axon hillock

specialized part of a neuron's cell body that connects to the axon. As a result, the initial segment or axon hillock is the site where action potentials originate.

Pain threshold

the intensity of a stimulus at which a subject says, "It's painful" half of the time, and, "It's not painful" the other half of the time.

Synaptic transmission

the major way that neurons communicate with each other across the small gap between the presynaptic site and postsynaptic site called the synaptic cleft.

GABA (gamma-aminobutyric acid)

your brain's main inhibitory neurotransmitter. It slows everything down and helps keep your systems in balance. It helps regulate anxiety.

Receptors

proteins that contain binding sites for particular neurotransmitters.

Neurotransmitters

chemicals that are released by the axon terminal and convey the message across the synapse to another cell.

Acetylcholine (ACh)

It excites cells, activates muscles, and is involved in wakefulness, attentiveness, anger, aggression, and sexuality. Alzheimer's disease is associated with a shortage of acetylcholine.

Why do we experience pain

It serves as protection to prevent further injury

Analgesics

drugs that reduce pain.

Glutamate

a major neurotransmitter that excites other neurons. It is dispersed widely throughout the brain. It's involved in learning and memory.

Integration

adding or combining a number of individual signals into one overall signal.

Epinephrine

also known as adrenaline, keeps you alert and your blood pressure balanced, and it jumps in when you need energy. It's produced and released by the adrenal glands in times of stress. Too much can increase anxiety or tension.

Pain

an unpleasant sensory and emotional experience associated with actual or potential tissue damage

Excitatory postsynaptic potentials (EPSP)

graded postsynaptic depolarizations, which increase the likelihood that an action potential will be generated.

Inhibitory postsynaptic potentials (IPSP)

graded postsynaptic hyperpolarizations, which decrease the likelihood that an action potential will be generated.

Serotonin

helps regulate body temperature, memory, emotion, sleep, appetite, and mood. Many antide- pressants work by regulating serotonin.

Receptor-gated ion channels

ion channels that open or close in response to the binding of a neurotransmitter.

Dopamine

is vital for voluntary movement, attentiveness, motivation and pleasure.

Pain tolerance

maximum level of pain people will voluntarily accept

Dynein

minus-end directed motor that carries cargo from the axon terminal to the cell body along microtubules.

Retrograde transport

movement of materials from axon terminals to the cell body

Anterograde transport

movement of materials from cell body to axon terminals.

Projection neuron

neuron whose axons make synapses in the brain.

Kinesin

plus-end directed motor that carries cargo from the cell body to the axon terminal along microtubules.

Endocytosis

process by which matter is taken in by a living cell by invagination of its membrane to form a vesicle.

Exocytosis

process by which the contents of membrane bound vesicle are released to the exterior through fusion of the vesicle mem- brane with the cell membrane.