Neurotransmitter & Drugs 1

Question 1

what is the inverted U-shaped dose effect curve?

Answer 1

a graph of the number of lever presses vs the dose rats receive, the ascending limb gives a reinforcing effect by making rats want more drug while the descending limb has a rate-limiting effect when the side effects of too much cocaine start to offset the rewarding factor of the cocaine

Question 2

what does up, down, left, and right shifts of the dose-effect curve mean?

Answer 2

up: more efficacious, higher maximum effect
down: less efficacious, lower maximum effect
left: more potent
right: less potent

Question 3

what are some genetic strategies to manipulate receptor expression?

Answer 3

using CRISPR-Cas9 or mutations to knock-out receptors, using viruses to increase translation and therefore induce overexpression of receptors, using siRNA or shRNA-mediated receptor knock down to bind to mRNA and trigger degradation which reduces the number of receptors

Question 4

what is the drug discrimination paradigm?

Answer 4

approach used to discover receptor families based on the assumption that drugs with similar subjective effects bind to similar receptors, involves training animal to press lever in response to reaction or no reaction, which indicates which drugs have similar effects and therefore similar receptors

Question 5

what are the three major classes of neurotransmitters?

Answer 5

small-molecule NTs, neuropeptides, and retrograde messengers

Question 6

what are the three kinds of small-molecules neurotransmitters?

Answer 6

acetylcholine, monoamines and amino acid NTs

Question 7

what are the two types of monoamines and what falls under them?

Answer 7

catecholamines: dopamine, norepinephrine, and epinephrine
indolamines: serotonin, melatonin

Question 8

what are the amino acid neurotransmitters?

Answer 8

glutamate, GABA, and glycine

Question 9

what are the three major classes of drugs of abuse?

Answer 9

depressants, stimulants, and hallucinogens

Question 10

what are the two types of depressants and what falls under them?

Answer 10

narcotics: produce analgesic effects (opioids/opiates)
sedative hypnotics: produce anxiolytic and anesthetic effects (alcohol, benzodiazepines line valium and xanax, barbituates, ketamine, and GHB)

Question 11

what are stimulants and what are some examples?

Answer 11

drugs that speed up mental and physical functioning (caffeine, nicotine, amphetamine, cocaine, methamphetamine, and MDMA/ecstasy)

Question 12

what are hallucinogens and what are some examples?

Answer 12

drugs that alter perception (LSD, psilocybin, PCP, THC/cannabis, salvinorin A/salvia, MDMA/ecstacy, ketamine, and GHB)

Question 13

how does the synthesis of acetylcholine work?

Answer 13

acetyl-CoA (the metabolic product of glucose from the mitochondria) and choline (an essential nutrient taken in via choline transporters, rate-limiting step) are made into acetylcholine and co-enzyme A by the enzyme choline acetyl transferase (ChAT)

Question 14

how does termination of acetylcholine synthesis/release work?

Answer 14

acetylcholine is degraded by acetylcholine esterase (AChE) in the synaptic cleft and broken down into acetate and choline (choline is taken up and recycled back into more acetylcholine)

Question 15

what are some characteristics unique to acetylcholine?

Answer 15

acetylcholine only has post-synaptic receptors therefore is it always degraded in the synaptic cleft

Question 16

what are some drugs that act on acetylcholine?

Answer 16

organophosphates are acetylcholine agonist insecticides that cause acetylcholine to build up and become toxic, sarin and tubin are acetylcholine enzyme inhibitors that prevent acetylcholine from being degraded and cause a build up

Question 17

what are some characteristics of nicotinic cholinergic receptors?

Answer 17

nicotinic cholinergic receptors are pentameric ionotropic receptors with two binding site, they can also act as cation channels and cause excitatory action in the neuromuscular junction, acetylcholine can be excitatory or inhibitory

Question 18

what are some drugs that act on nicotinic cholinergic receptors?

Answer 18

nicotine in a direct agonist, curare is a direct agonist that causes paralyzation, a-bungarotoxin is a peripheral direct antagonist that paralyzes you while you are conscious, and a-conotoxin is a direct antagonist that blocks nicotinic acetylcholine receptors that are in the CNS and PNS

Question 19

what are some characteristics of muscarinic cholinergic receptors?

Answer 19

they are metabotropic G-protein coupled receptors with a single binding site, they are the dominant acetylcholine receptor in the CNS, are inhibitory in the parasympathetic nervous system/heart, can be Gq, Gi/o, or have open/close K+ channels (shortcut pathway)

Question 20

what are some drugs that act on muscarinic cholinergic receptors?

Answer 20

muscarine is a direct agonist, atropine/belladonna is a direct agonist, and scopolamine/henbane is a direct antagonist that cause amnesia since acetylcholine helps consolidate memories

Question 21

how does nicotine work?

Answer 21

acts as a direct nicotinic acetylcholine receptor agonist in the PNS and CNS that is highly toxic (insecticide, TI=3), acts to indirectly increase dopamine levels in the CNS, withdrawal causes craving, insomnia, anxiety, and flu-like symptoms, follows a titration pattern of use