neurotransmitter (Exam 2)

What is a neurotransmitter?

A chemical messenger that allows neurons to communicate

What triggers neurotransmitter release?

An action potential reaching the axon terminal

What ion causes neurotransmitter release?

Calcium (Ca2+)

What are the two major types of neurotransmitter receptors?

Ionotropic and metabotropic

What is an ionotropic receptor?

A ligand-gated ion channel

What happens when a neurotransmitter binds to an ionotropic receptor?

The channel opens and ions flow through

Are ionotropic receptors fast or slow?

Fast

What kind of effects do ionotropic receptors produce?

Immediate effects

What is a metabotropic receptor?

A G-protein-coupled receptor

What happens when a neurotransmitter binds to a metabotropic receptor?

A G-protein activates a signaling cascade

Do metabotropic receptors contain ion channels?

No

Are metabotropic receptors fast or slow?

Slow

What kind of effects do metabotropic receptors produce?

Long-lasting and widespread effects

What is a G-protein?

A protein activated by metabotropic receptors

What is a second messenger?

A molecule that carries signals inside the cell

What are examples of second messengers?

cAMP and calcium

Can metabotropic receptors alter gene expression?

Yes

What type of receptor directly opens an ion channel?

Ionotropic receptor

What type of receptor uses a signaling cascade?

Metabotropic receptor

Do most neurotransmitters have both ionotropic and metabotropic receptors?

Yes

What are the four major classes of neurotransmitters?

Amino acids, amines, peptides, and gases

What are the main amino acid neurotransmitters?

Glutamate and GABA

What is the main excitatory neurotransmitter?

Glutamate

What is the main inhibitory neurotransmitter?

GABA

What does glutamate do?

Excites neurons and helps with learning and memory

What receptors are associated with glutamate?

AMPA and NMDA receptors

What does GABA do?

Inhibits neuronal activity

What ion enters through GABAA receptors?

Chloride (Cl-)

Is GABAA ionotropic or metabotropic?

Ionotropic

Is GABAB ionotropic or metabotropic?

Metabotropic

Why are glutamate and GABA important?

They maintain excitation-inhibition balance

What are the major amine neurotransmitters?

Acetylcholine, dopamine, norepinephrine, and serotonin

What is acetylcholine (ACh) involved in?

Learning, memory, muscle contraction, and the autonomic nervous system

Where is acetylcholine primarily produced?

Basal forebrain

Which neurotransmitter is first lost in Alzheimer's disease?

Acetylcholine

What neurotransmitter controls skeletal muscle contraction?

Acetylcholine

What is dopamine involved in?

Movement, reward, reinforcement, and mood

Where is dopamine produced?

Substantia nigra and VTA

What brain area uses dopamine for movement?

Substantia nigra

What brain area uses dopamine for reward?

VTA

Loss of dopamine neurons causes what disorder?

Parkinson's disease

What neurotransmitter is dysregulated in schizophrenia?

Dopamine

What is norepinephrine involved in?

Alertness, vigilance, mood, and sexual behavior

Where is norepinephrine produced?

Locus coeruleus

Which neurotransmitter is associated with the sympathetic nervous system?

Norepinephrine

What is serotonin involved in?

Mood, anxiety, sleep, appetite, and sexual behavior

Where is serotonin produced?

Raphe nuclei

What neurotransmitter is abbreviated 5-HT?

Serotonin

Main excitatory neurotransmitter?

Glutamate

Main inhibitory neurotransmitter?

GABA