Chapter 9 Psychoactive Drugs Flashcards
Caffeine
powerful stimulant, acts on CNS to increase wakefulness/alertness (acts on cardiovascular system to increase heart rate and blood pressure)
molecular structure similar to adenine and guanine (acts at adenosine receptors as an antagonist)
Theophylline
closely related to caffeine
(1,3-dimethylxanthine)
found in tea
Theobromine
closely related to caffeine
(3,7-dimethylxanthine)
found in cacao
Adenosine
caffeine acts as antagonist to adenosine receptors (which are GPCRs - effect as an inhibitory neurotransmitter is not a direct effect on opening of an ion channel)
adenosine receptors in heart mediate a slowing heart rate, in blood vessels mediates vasodilation (opening up of vessels), in the brain decreases neuronal exceitability
Tobacco
primary chemical is nicotine
Nicotine
binds as agonist at nicotinic acetylcholine receptors
effects related to behavioral effects of relaxation, alertness, focused attention
can overstimulate nAChRs in insects; produce disruptions in heart rhythm, blood pressure, and respiration
alcohol
two-carbon ethyl alcohol or ethanol
ethanol/ethyl alcohol
least poisonous of all organic alcohols
produced through metabolic action of yeast on sugars (fermentation)
sedative-hypnotic drug
sedative-hypnotic drugs
in low doses, produce sedative/relaxing effect
in high doses, produce hypnotic /sleep inducing effect
Ethyl alcohol most ancient and widely used
Barbiturates
synthetic sedative hypnotic drugs manufactured and sold for medical use
used to treat anxiety and insomnia
examples: phenobarbital, secobarbital, amobarbital, pentobarbital, thiopental
neurochemical action of sedative-hypnotic drugs
act at ionotropic GABA receptors, facilitate action of GABA at receptor
–>increases inhibition in the CNS by increasing GABA induced Cl- flow into cells
Results:
low doses- relaxing, anxiety-reducing effects
higher doses- impaired movement and memory storage
high doses- loss of consciousness
extremely high doses- death
benzodiazepines
synthetic sedative-hypnotic drug
similar to barbiturates
general anesthetics
category of sedative-hypnotic drugs used in medicine; induce loss of sensation
first general aesthetic to be used in medicine was ethanol (whiskey) - diethyl ether
opium poppy (Papaver somniferm)
cultivated by ancient Sumerians of Mesopotamia
“joy plant” produces psychoactive effects of relaxation, pain relief, and euphoria
other effects: cough suppression, slowed motile muscle action of intestines (used as treatment for diarrhea)
morphine
chemical constituent of opium ; found by Serturner
opioids
opium-like compound that binds to one or more of the three opioid receptors of the body
Friedrich Wilhelm Seturner
isolated and purified morphine from opium
demonstrated effects of morphine when ingested (analgesic, soporific, euphoric effects of opium but more potent)
*first time a chemical substance had been isolated from a plant and shown to account for the medicinal properties of the plant
heroin
opioid, introduced as an analgesic (pain relief) and cough medicine in 1898
semi-synthetic opioid
chemicals having opium-like effects in the body
first one was diacetylmorphine
fentanyl
synthetic opioid; 100 times more potent than morphine
widely used in human medicine
certain derivatives are the most potent opioids known and among the most potent of any drugs presently known, naturally occurring or synthetic
synthetic opioids
opioids that are made completely synthetically
opioid receptor
found to exist in several distinct subtypes (mu, delta, kappa) having differeing distributions in the brain and body and different pharmacological properties (different agonist, antagonists)
all are known to be GPCRs
endorphins
found in the brain, function as agonists at opioid receptors first of a new class of neurotransmitters (neuropeptides) chain of amino acids name derived from endogenous and morphine
agonist
a chemical that binds to and activates a receptor
Erythroxylum coca
plant from which cocaine is derived
native to South America
cocaine
chemical isolated from the coca plant
local anesthetic
powerful stimulant effects: increased wakefulness, focused attention, decreased fatigue, increased stamina
high potential to promote addictive use
effects of cocaine
similar to those of caffeine
in addition: decreased appetite, increased positive mood, stimulation of sympathetic nervous system; beneficial effects on the digestive system
cocaine at synapses
blocks/inhibits reuptake transporters for the neurotransmitters norepinephrine and dopamine (will be slowed when leaving the synaptic cleft and thus will have greater effect at the synapse after their release)
enhanced activity at the noradrenergic and dopaminergic circuitry in the brain (CNS stimulant effects
Cocaine and the CNS
overarousal of the CNS resulting in anxiety, irritability, impaired judgement, psychosis, seizures, cardiovascular stress (leading to heart and circulatory system damage), stroke, heartattack
psychosis
discombobulation of the perception of what we call reality, characterized by delusions/hallucinations
amphetamine related drugs
similar to cocaine in effects on nervous system and behavioral attributes, but not related to cocaine in origin or molecular structure
amphetamine at synpases
neurochemical action at synapses using norepineprine or dopamine as neurotransmitter
causes reuptake transporters to become leaky (neurotransmitter leads out of axon terminal into the synaptic cleft, causing overstimulation of neural circuits)
psychedelics
produce a variety of complex effects on the brain and mind, including intensified thoughts and feelings and altered sensory perception
large set-and-setting effect
hallucinogen
another word for psychedlic
Peyote cactus
small cactus found in Mexico; has potent psychoactive properties
Arthur Heffter
identified Mescaline from peyote cactus
Mescaline
first psychedelic substance to be chemically identified
LSD
most famous psychedelic chemical
derived from ergotamine
one of the most potent psychoactive substances known
synthesized by Albert Hofmann
Albert Hofmann
synthesized and tested LSD
landmark event in history of neuroscience - powerful chemical connections between brain physiology and mental experience
Psilocybe mushrooms
sometimes referred to as “magic mushrooms” that grow throughout the world; shamanic use is known from the Mazatec peoples of southern Mexico using it in their rituals
Gordon Wasson
New York City bank executive and mushroom scholar who revealed psychadelic mushrooms in 1957 via article in Life magazine
Maria Sabina
Mazatec healer from a small mountain village in Mexico; shared ritual use of psychedelic mushrooms
psilocybin
one of the two psychedelically active chemicals from mexican psilocybe mushroom; the other is psilocin
DMT
powerful psychedelic molecule (looks similar to serotonin and psilocin)
can be readily synthesized by enzymes present in many organisms, amino acid tryptophan
found to occur widely in nature and the human body
Ayahuasca
also called yage; made by amazonians by cooking a combination of DMT containing plant with the ayahuasca vine
Cannabis
originated in central Asia; appreciated for fiber properties (strong rope and durable cloth) and powerful medicinal/psychological applications: analgesic, muscle relaxant, appetite stimulant, sedative, stimulant, psychedelic-like change of consciousness
Tetrahydrocannabinol (THC)
major psychoactive chemical constituent of cannabis; one of ~60 different chemically related molecules found in cannabis (called cannabanoids);very hydrophobic molecule, easily sticks to lipids and dissolves into phospholipid bilayer membrane; interacts with CB receptor (a type of GPCR); occurs everywhere in brain (most abundant of all known GPCR receptors in the vertebrate brain)
anadamide
an endogenous (originating from within) agonist of the CB receptor; first of several molecules to be discovered that appear to function as neurotransmitters at the CB receptor
endocannabinoids
endogenous agonist of CB receptor
synthesized and released from post-synaptic dendrites in response to glutamatergic stimulation, then travels across synaptic cleft to interact with CB receptors on presynaptic axon terminals; example of a retrograde neurotransmitter (molecule that carries signal info in the direction opposite from the way neural signals are generally thought to move
retrograde signaling
retro - backward
example: endocannabinoids
intimately involved in the dynamic tuning of the strengths of synapses
