Chapter 4 Flashcards
Exogenous/Endogenous
Exogenous-substances from outside the body (drugs etc)
Endogenous-substance from inside the body
Exocytosis
When the action potential reaches the axon terminal and Ca2+ ions open and allow vesicles of neurotransmitter to bind with the membrane and spill into the synaptic cleft.
Reuptake/Transmitters
Reuptake-When neurotransmitters are broken down by enzymes and brought back into the presynaptic terminal
Transporter-special protiens that bind molecules of transmitter and conduct the back inside.
Ionotropic receptors/Metabotropic receptors
Ionotropic-“fancy” ion channels that change their shape to open or close the ion channel
Metabotropic- don’t contain ion channels and instead link across membrane to complicated chemical machinery inside the postsynaptic neuron.
Amino Acid neurotransmitters
Most common in the brain. Gamma-aminobutyric (GABA-inhibitory), glutamate (excitatory)
Amines
ex. Quaternary amines-Acetylcholine (ACh)
Monoamines-Cateholamines=Norepinephrine (NE), epinephrine (adrenaline), dopamine (DA)
Indoleamines=Serotonin (5-HT), melatonin
Neuropeptides
Opioid peptides(mimic the actions of opiate drugs like morphine marking analgesia and reward), oxytocin, vasopressin
Gasses
ex. Carbon monoxide, Nitric oxides
soluble gas that diffuse between neurons and alter ongoing process.
Cholinergic
ACh containing neurons that are found in the basal forebrain
Basal Forebrain
Region, ventral to the basal ganglia, that is the major source of ACh in the brain
Substantia Nigra
A brainstem structure innervates the basal ganglia and is a major source of dopaminergic predictions
Ventral Tegmental Area (VTA)
Portion of the midbrain that projects dopaminergic fibers to the nucleus accumbens
Raphe nuclei
string of nuclei in the midline of the midbrain and brainstem that contain most of the serotonergic neurons of the brain
Noradrenergic/Norepinephrine (NE)
known as noradrenaline, a neurotransmitter produced and released by the sympathetic post-ganglionic neuron to accelerate organ activity
Locus coeruleus
A small neucleus in the brainstem whose neurons produce norepinephrine and modulate large areas of the forebrain
Lateral tegmental area
brainstem region that provides some of norepinephrine-containing projections of the brain.
Retrograde transmitter
Neurotransmitter that diffuses from the postsynaptic neuron back to the presynaptic neuron
Ligand
A substance that binds to receptor molecules such as neurotransmitter or drug that binds postsynaptic receptors
Binding Affinity
Chemical attraction which molecules of a drug bind to receptors
Efficacy
“intrinsic activity” The extent to which a drug activates a response when it binds to a receptor.
Bioavailable
substance, usually a drug, that is present in the body in a form that is able to interact with physiological mechanisms. Free to act on target tissue, not being eliminated.
Biotransformation
Process of enzymes converting a drug into a metabolite that is active, could possibly have greatly different actions from the original substance
Pharmacokinetics
the name for all the factors that affect the entire movement of a drug through the body.
Tolerance (drug, metabolic, functional, cross)
Drug - repeated exposure to a drug allows the body to be less responsive to that drug.
Metabolic - body becomes more efficient at cleaning out the drug
Functional - receptors in synapse become accustom to drug, and change its sensitivity to down-regulate (decrease receptor availability) and up-regulate (increase receptor availability).
Cross - gain tolerance to another drug within the similar chemical class
Autoreceptor
receptor located in the presynaptic membrane that tells the axon terminal how much transmitter has been released
Understanding Drug Abuse
- Moral model = addiction results form weakness or character or lack or control
- Disease model = abusing drugs requires medical treatment or punishment
- Physical development = people keep taking drugs to avoid unpleasant withdrawal symptoms
- Positive reward model = people start with drug abuse and become addictive because it is a powerful reinforcement.
Nucleus accumbens
region of forebrain that receives dopaminergic innervation from the ventral tegmental area, often associated with reward and pleasurable sensations
Insula
region of cortex below the surface within the lateral sulcus of the frontal, temporal, and parietal lobes. Could be involved with addiction. Connections between Ventral Tegmental area (VTA) and this suggest the two regions interact to mediate addiction.
