Chapter 4: The Chemistry of Behavior Flashcards
Criteria of classic neurotransmitters
- Present in synaptic axon terminals
- Presynaptic cell has enzymes for NT (makes for a reason)
- Action potentials produce significant release of NTs
- NT receptors located on the postsynaptic cell
- Application of NT produces change in postsynaptic cell
- If you block NT release, it prevents the postsynaptic effects
Neuropharmacology
The discovery and study of compounds that selectively affect the functioning of the nervous system.
Neuropeptides
Short string of amino acids
Retrograde Transmitters
Go from postsynaptic cell to presynaptic cell (backwards)
Amino Acids (ex)
GABA and Glutamate
GABA
Primary fast inhibitory NT
Glutamate
Primary fast excitatory NT
Monoamines (ex)
NTs involved in regulating mood and memory
Dopamine, Norepinephrine,
and Epinephrine are all…
Monoamines
Acetylcholine
A compound that functions as a NT
Ligand
Any substance that binds to a receptor and has some sort of effect
Agonists
Substances that mimic hormones/neurotransmitters to trigger a response when they bind to a receptor
Antagonists
Substances that block the action of other substances, such as agonists.
Inverse Agonist
Produces opposite effect from normal activation of a receptor
Competitive Ligand
A drug that binds to the same receptor site as another ligand/agonist and prevents the agonist from binding and activating the receptor.
Non-Competitive Ligand
A compound that binds to a receptor protein at a different site than an agonist and prevents the agonists biological response
Nicotinic Receptor
Ionotropic and Excitatory
Muscarinic Receptor
Postganglionic cells of autonomic system (parasympathetic)
Dopamine D1 and D5
Stimulate production of cyclic AMP (cAMP)
Dopamine D2, D3, and D4
Inhibit production of cAMP
Ventral Tegmental Area (VTA): DA Neurons
Involved in reward, emotion, reinforcement, and addiction
Substantia Nigra: DA Neurons
Innervate the dorsal striatum = motor control
Parkinsons Disease
Destruction of Substantia Nigra dopamine neurons
Norepinephrine a1
Activates Phospholipase C
Norepinephrine B1 and B2
Stimulatory to cAMP system
Norepinephrine a2
Inhibitory to cAMP system
Serotonin
Involved in mood, anxiety, sleep, and variety of other functions
Generalization
The RECEPTOR determines whether NT is excitatory or inhibitory
GABA
The primary inhibitory NT in the central nervous system
GABA A
Receptor, Ionotropic, Chloride Channel
GABA B
Receptor, Metabotropic, Slow IPSP
Glutamate
Primary fast excitatory NT in the Central Nervous System
NMDA Receptor
Magnesium block requires depolarization to open
AMPA Receptor
Sodium channels that when open, produce EPSP
Glutamate Synapses
Found on dendritic spine heads
GABA Synapses
Found on the dendritic shaft of spine, cell bodies, and close to axon hillock
Peptide
Co-Transmitters
Opioid Peptide
Usually released with GABA from GABAergic neurons
Gases
Often retrograde. Simply diffuses across cell membrane
Gas Example
Nitric Oxide
Binding Affinity
The strength of the binding interaction between a single biomolecule (protein/DNA) to its ligand/binding partner
Dose Response Curve
The graphical relationship between the dose of a drug versus the effects the drug exerts on the system.
Metabolic Tolerance
Tolerance is built due to change in how the drug is metabolized (by the liver)
Functional Tolerance
The ability of an individual’s brain to adapt and operate normally even when exposed to high levels of alcohol or drugs
- Underlies withdrawal symptoms
Sensitization
The opposite of tolerance
Serotonin Reuptake Transporter
SERT
Norepinephrine Reuptake Transporter
NET
Dopamine Reuptake Transporter
DAT
1st Generation Antipsychotics
Antagonist activity at dopamine D2 receptors
2nd Generation Antipsychotics
Actions other than or in addition to D2 receptor
Antidepressent
Class of drugs that relieve symptoms of depression
Monoamine Oxidase (MAO) Inhibitors
A class of enzymes that break down and thereby inactivate monoamine transmitters
Anxiolytics
A class of substances that are used to combat anxiety
Anxiolytics Examples
Alcohol, Opiates, Barbiturates, and Benzodiazepines
Depressents
A drug that reduces the excitability of neurons
Barbiturate
A powerful sedative anxiolytic with dangerous addiction and overdose potential
Benzodiazepine Agonists
A class of anti-anxiety drugs that bind to sites on GABA A receptors
Neuroactive Drugs
Drugs used to alter consciousness
Efficacy
The extent to which ligand activated receptor.
- May not activate it as well as another drug.
Competitive Ligand
Competes with it for its binding site.
Non-Competitive Ligand
Will bind to a place where the neurotransmitter does not bind to.
Exogenous
Comes from outside the body
Endogenous
Comes from inside the body
iGluRs
Ionotropic Glutamate Receptors
Direct
Binds directly to the receptor site
Indirect
Blocking reuptake / “do something else”
- Does not bind to receptor site
ED 50 Curve
Dose that produces half the maximal effect
Maximal Response Curve
Where the drugs response maxes out
Therapeutic Index Curve
Distance between LD50 and TD50
LD50
Dose that kills half of the people/animals that receive it
TD50
Dose that produces toxicity in half of the people/animals that receive it.
Upregulation
The more the receptors, the more neurotransmitters bind.
Down regulation
When agonists bind for a longer time = desensitization
Tricyclics
Block NET and SERT
Alcohol
Structure is very similar to water which allows it to flow freely through the body.
