Neurotransmitters and Drug Actions

These flashcards cover key terms and concepts related to neurotransmitters, their functions, drug actions, and effects on synaptic transmission.

Neurotransmitters

Chemicals stored in synaptic vesicles released at the presynaptic membrane.

Agonist

A drug that facilitates the effects of a particular neurotransmitter on the postsynaptic cell.

Antagonist

A drug that opposes or inhibits the effects of a particular neurotransmitter on the postsynaptic cell.

Direct Agonist

A drug that binds with and activates a receptor.

Receptor Blocker

A drug that binds with the receptor but does not activate it, preventing the natural ligand from binding.

Indirect Agonist

A drug that attaches to a binding site on a receptor and facilitates the action of the receptor without interfering with the principal ligand's binding site.

Indirect Antagonist

A drug that attaches to a binding site on a receptor and interferes with the action of the receptor, without affecting the principal ligand's binding site.

Reuptake

The process by which molecules of neurotransmitters are taken back into the terminal button.

Acetylcholine (ACh)

A neurotransmitter involved in muscle movement and found in both the CNS and at target organs of the parasympathetic ANS.

Dopamine (DA)

A neurotransmitter implicated in movement, attention, learning, and the reinforcing effects of drugs.

Norepinephrine (NE)

A neurotransmitter involved in arousal and alertness, often synonymous with adrenaline.

Serotonin (5-HT)

A neurotransmitter involved in mood regulation, sleep, eating, and arousal.

Glutamate

The principal excitatory neurotransmitter in the brain and spinal cord.

GABA (Gamma-aminobutyric acid)

The main inhibitory neurotransmitter in the brain and spinal cord.

Opioids

Natural ligands for opiate receptors that reduce pain and induce feelings of pleasure.

Adenosine

A neuromodulator that regulates blood flow and suppresses neural activity.

Nitric Oxide (NO)

A soluble gas that acts as a messenger in various biological processes.

Strychnine

A toxic substance that acts as a glycine antagonist.

L-DOPA

A precursor to dopamine used in treating Parkinson's disease.

Caffeine

A stimulant that blocks adenosine receptors, producing excitatory effects.

Botulinum toxin

Blocks the release of acetylcholine, leading to paralysis.