Neuro psych Quiz 2.2 Flashcards
Neurotransmitters
chemicals released by a neuron that affect another neuron
What are the major categories of neurotransmitters?
1) Amino acids
2) monoamines
3) acetylcholine
4) neuropeptides
5) purines
6) gases
Amino acids
Acids containing an amine group (NH2)
monoamines
Chemicals formed by a change in certain amino acids
acetylcholine
a chemical similar to an amino acid, except that it includes an N(CH3)3 group instead of an NH2
neuropeptides
chains of amino acids
purines
a category of chemicals including adenosine and its derivatives
gases
nitric oxide and others
what is the oddest transmitter?
Nitric oxide
What does a highly active brain area do to increase its blood supply?
it releases nitric oxide which dilates the blood vessels in the area and increases blood flow.
Catecholamines
compounds that contain a catechol group and an amine group (epinephrine, norepinephrine, and dopamine)
vesicles
tiny spherical packets that store high concentrations of neurotransmitter molecules.
Monoamine oxidase (MAO)
breaks down transmitters (serotonin, dopamine, norepinephrine) into inactive chemicals
What was the first antidepressant drugs that psychiatrists discovered?
MAO inhibitors
exocytosis
bursts of release of neurotransmitter from from the presynaptic neuron after calcium enters the terminal
ionotropic effects
effects begin quickly and decay swiftly. Good for visual, auditory, and any other information that needs to be given swiftly
transmitter-gated/ligand-gated channels
channels controlled by a neurotransmitter
What is the most common ionotropic inhibitory
GABA
metabotropic effects
initiates a sequence of metabolic reactions that are slower, and longer lasting
G-protein
a protein coupled to guanosine triphosphate, an energy storing molecule
second messenger
communicates to many areas in the cell (cAMP)
neuromodulators/neuropeptides
synthesized in the cell body, released from dendrites, cell body, and sides of axon, released by repeated depolarization, release the neuropeptides at neighboring cells, diffuse to a wide area, and last for several minutes.
hallucinogenic drugs
drugs that distort perception, such as LSD
Nicotine
compound present in tobacco, stimulates a family of acetylcholine receptors
Opiate drugs
Derived from the opium poppy
acetylcholinesterase
breaks down acetylcholine
catechol-o-methyltransferase (COMT)
enzyme that breaks down any transmitter molecules not taken up by transporters
Examples of stimulant drugs that inhibit the transporters for dopamine
amphetamine and cocaine
Methylphenidate (Ritalin)
stimulant drug for ADHD
What happens to acetylcholine molecules after they stimulate a postsynaptic receptor?
acetylcholinesterase breaks int down into acetate and choline which are then reabsorbed by the presynaptic terminal
What happens to 5-HT and catecholamine molecules after they stimulate a postsynaptic receptor?
Most are reabsorbed by pre terminal. Some are broken down into inactive chemicals
How do amphetamines and cocaine influence dopamine synapes?
They interfere with reuptake and release of dopamine
Why is methylphenidate generally less disruptive to behavior than cocaine is despite the drugs similar mechanisms?
The effects develop and decline in the brain slower than cocaine.
auto receptors
receptors that respond to the released transmitter by inhibiting further synthesis and release.
What are two neurons that respond to stimulation by releasing chemicals that travel back to the presynaptic terminal to inhibit further release?
anandamide and 2-AG
Cannabinoids
Active ingredient in marihuana. bind to anandamide or 2-AG on presynaptic terminals
How do cannabinoids affect neurons?
Cannabinoids released by the postsynaptic neuron attach to receptors on presynaptic neurons, where they inhibit further release of both glutamate and GABA
gap junction
Where the membrane of one neuron comes in touch with the membrane of another.
hormone
a chemical secreted by cells in one part of the body and conveyed by the blood to influence other cells
Two types of hormones composed of chains of amino acids that attach to membrane receptors and activate a second messenger.
protein hormones (longer) and peptide hormones (shorter)
Two parts of pituitary gland
anterior and posterior (considered an extension of hypothalamus)
What hormones does neurons in the hypothalamus synthesize
oxytocin and vasopressin
releasing hormones
released by hypothalamus. flow to anterior pituitary through blood. Stimulate or inhibit release of other hormones
Which part of the pituitary is neural tissue similar to the hypothalamus?
posterior
Which part of the pituitary is glandular tissue and produces hormones that control the secretions by other endocrine organs?
anterior
in what way is a neuropeptide intermediate between neurotransmitters and hormones?
1) most neurotransmitters are released in small amounts close to receptors
2) Neuropeptides are released into a brain area in larger amounts or not at all and diffuse more widely
3) Hormones are released into the blood for diffuse delivery throughout the body
What was Leowi’s evidence that neurotransmission depends on the release of chemicals?
He stimulated one frog’s heart, collected fluid around it, transferred it to another frog’s heart, and saw change in its heart rate.
What are the brain’s neurotransmitters?
Glutamate
GABA
Serotonin
The amino acid tryptophan is a precursor to which neurotransmitter?
Serotonin
How could you cause the presynaptic terminal of an axon to release its transmitter without an action potential?
Inject calcium into the presynaptic terminal
The brain’s most abundant excitatory neurotransmitter is what
Glutamate
The brain’s most abundant inhibitory neurotransmitter is what
GABA
In what ways does a metabotropic synapse differ from an ionotropic synapse?
Its effects are slower to start and last longer
What is a second messenger?
A chemical released inside a cell after stimulation at a metabotropic synapse
What is true of neuropeptides?
They are released in large quantities or not at all
What drug exerts its behavioral effects by binding to the same receptor as a neurotransmitter?
Nicotine
Which neurotransmitter is broken into two pieces to inactivate it, after it excites the postsynaptic neuron?
Acetylcholine
What does a transporter protein do at a synapse?
It pumps used neurotransmitter molecules back into the presynaptic neuron
Except for the magnitude of speed of effects, methylphenidate affects synapse the same way as what other drug?
Cocaine
What drug acts by inhibiting release of neurotransmitters from presynaptic neurons?
Cannabinoids
In contrast to the posterior pituitary, the anterior pituitary…
Is glandular tissue that produces hormones that control other endocrine organs
