3.3 Synapses, Drugs, And Addictions Flashcards
A drug that blocks a neurotransmitter is an ____, where as a drug that mimics or increases the effects is an ____.
antagonist : agonist
Drugs either ____ or ____ transmission at synapses.
facilitate or inhibit
A ____ ____ is an agonist for some effects of the neurotransmitter and an antagonist for others or an agonist at some doses and an antagonist at others.
mixed agonist–antagonist
A drug has an ____ for a receptor if it binds to it, like a key into a lock. Affinities vary from strong to weak.
affinity
A drugs ____ is its tendency to activate the receptor. A drug that binds to a receptor but fails to stimulated it has a high affinity but low efficacy.
efficacy
Reinforcing brain stimulation, reinforcing experiences, and self-administered drugs increase the activity of axons that release ____ or ____ in the nucleus accumbens.
dopamine or norepinephrine
____ drugs increase excitement, alertness, and activity, while elevating mood and decreasing fatigue.
Stimulant
Both ____ and ____ stimulate dopamine synapses in the nucleus accumbens and elsewhere by increasing the presence of dopamine in the presynaptic terminal.
amphetamine and cocaine
Reuptake: the presynaptic terminal ordinarily reabsorbs released dopamine through a protein called the ____ ____. Amphetamine and cocaine inhibit the transporter, thus decreasing reuptake and prolonging the effect of released dopamine.
dopamine transporter
Amphetamine has similar effects on the ____ and ____ transporters. Methamphetamine has effects similar to those of amphetamine, but stronger.
serotonin and norepinephrine
Thus, stimulant drugs increase the ____ of dopamine in the synaptic cleft.
accumulation
Excess dopamine in the synapses washes away faster than the presynaptic cell makes more to replace it. A few hours after taking a stimulant drug, the user has a deficit of the transmitters and enters a ____ ____, marked by reduced energy, reduced motivation, and mild depression.
withdrawal state
Stimulant drugs produce varied behavioural effects. ___ doses enhance attention, and ___ doses of amphetamine are sometimes used as a treatment for attention deficit disorder. However, ___ doses of stimulant drugs impair attention and learning.
Low : Low : high
By altering blood flow, cocaine also increases the risk of ____ and ____.
stroke and epilepsy
____ (Ritalin), another stimulant drug, is also prescribed for people with attention deficit hyperactivity disorder. Methylphenidate and cocaine block the reuptake of dopamine in the same way at the same brain receptors.
Methylphenidate
Nicotine, a compound present in tobacco, stimulates a family of acetylcholine receptors, conveniently known as ____ ____.
nicotinic receptors
Nicotinic receptors are abundant on neurons that release dopamine in the ____ ____, so nicotine increases dopamine release there.
nucleus accumbens
One consequence of repeated exposure to nicotine is that receptors in the nucleus accumbens become more ____ to nicotine. However they become less ____ to other kinds of reinforcement.
sensitive : responsive
____ drugs are derived from, or chemically similar to those derived from, the opium poppy. Familiar opiates including morphine, heroine, and methadone.
Opiate
Opiates relax people, ____ their attention to real-world problems, and ____ this sensitivity to pain.
decrease
Investigators found that the brain produces a certain neuropeptides known as ____ – a concentration of endogenous morphines.
endorphins
This discovery was important because indicated that ____ relieve pain by acting on receptors in the brain. This finding also paved the way for the discovery of other neuropeptides that regulate emotions and motivations.
opiates
Endorphins indirectly activate ____ release. Endorphin synapses inhibit neurons that release GABA, a transmitter that inhibits the firing of ____ neurons. By inhibiting and inhibitor, the net effect is to increase ____ release.
dopamine
Marijuana leaves contain chemical ____ (THC) and other cannabinoids (chemicals related to THC).
tetrahydrocannabinol
Common psychological effects of marijuana include an intensification of ____ ____ and an illusion that time has ____ ____. Studies have reported impairments of memory and cognition.
sensory experience : slowed down
Cannabinoid receptors are among the most ____ receptors in many areas of the mammalian brain.
abundant
The chemicals in marijuana decrease both ____ and ____ messages from many neurons.
excitatory and inhibitory
Cannabinoids relieve ____ by inhibiting serotonin type three synapses, which are known to be important for ____.
nausea
Cannabinoid receptors are abundant in areas of the hypothalamus and hippocampus that influence ____, and stimulation of these receptors increases the rewarding value of a ____.
feeding : meal
Drugs that distort perception are called ____ drugs.
hallucinogenic
Many hallucinogenic drugs, such as ____ ____ ____ (LSD), chemical resemble serotonin.
lysergic acid diethylamide
