ch 4: neurotransmitters and neuropharamcology Flashcards
Ligand
substance that binds to receptor molecules such as those at the surface of the cell
Ligands may be Agonists
molecule (usually a drug) that binds to a receptor and mimics effects of another transmitter
Ligands may be Antagonists
a molecule (drug) that interferes with or prevents the action of a transmitter
Inverse Agonists
a substance that binds to receptor and initiates opposite effect of usual transmitter
Receptor
a protein that binds and reacts to molecules of a neurotransmitter or hormone
Ionotropic receptor
a receptor protein that includes an ion channel that is opened when the receptor is bound by an agonist
Metabotropic receptor
a receptor protein that doesn’t contain an ion channel but may, when activated, use a G-protein system to alter the functioning of the postsynaptic cell
Endogenous
produced inside the body
Receptor agonist
when an exogenous ligand that resembles the endogenous ligand is capable of binding to the receptor and activating i
Competitive antagonists
a substance that directly competes with the endogenous ligand for the same binding site on a receptor molecule
noncompetitive agonist/antagonsit
also called neuromodulator
-some agonist or antagonist drugs may bind to target receptors at a site that is different from where the endogenous ligand binds
modulatory site
a portion of a receptor that, when bound by a compound, alters the receptor’s response to its transmitter
Amino Acids
GABA
Glutamate
Glycine
Amines
Acetylcholine (ACh)
2 main classes of 1)Monoamines- Catecholamines
norepinephrine (NE)
epinephrine (Adrenaline)
dopamine (DA)
2) Monoamines-Indoleamines
serotonin (5-HT)
melatonin
Neuropeptides: Opioid peptides
- Enkephalins
- Endorphins
- Dynorphins
Other Neuropeptides
Oxytocin
Substance P
Neuropeptide Y
Gases
Nitric Oxide
Carbon monoxide
Most prevalent excitatory neurotransmitters in the brain
Glutamate
Asparate
Excitotoxicity
-when neurons die when overstimulated, as with large amounts of Glutamate
GABAa receptor
ionotropic (ligand-gated chloride channels), producing fast, inhibitory postsynaptic potentials
GABAb receptor
metabotropic, producing slow inhibitory effects
GABAc receptor
ionotropic with a chloride channel
GABA agonists
due to the inhibitory actions, GABA agonists, like Valium, are potent tranquilizers
GABA
widely distributed amino acid transmitter; main inhibitory transmitter in the mammalian nervous system
Glycine
an amino acid transmitter, often inhibitory
Acetylcholine (ACh)
a neurotransmitter produced and released by parasympathetic neurons, motor neurons and neurons in the brain
- one of the first neurotransmitter to be discovered
- mapped by the enzymes involved in its synthesis
Cholinergic
referring to cells that use acetylcholine as their synaptic transmitter
- lost in Alzheimer’s disease
- involved w/ learning and memory
Nicotinic
-cholinergic receptors that respond to nicotine as well as ACh
Cholinergic Pathways in the Brain
- clusters found in the Basal Forebrain (media septal nucleus & nucleus of diagonal band & nucleus basalis
- found in the HIPPOCAMPUS& AMYGDALA
- found in the PEDUNCULOPONTINE NUCLEUS and LATERODORSAL TEGMENTAL NUCLEUS
Acetylcholine receptors
1) Nicotinic (nicotine)
2) Muscarinic (muscarine)
nicotinic receptor
fast, ionotropic
1) Neurotransmitter binds directly to the channel
2) channel opens
3) ions flow across membrane for a brief time
muscarinic receptor
slow, metabotropic
1) neurotransmitter binds G protein-coupled receptor
2) g protein activated
3) activated g-protein subunit moves to adjacent ion channel, which imposes a brief delay
4) channel opens, ions flow across membrane for a longer period of time
