Lecture 3 Flashcards
exogenous substances
from outside the body –> ingested to changed the functioning of the brain and the body
endogenous substance
internal substance –> ex: neurotransmitter
ionotropic receptors
change shape when transmitter molecule binds to it –> allows ions to come through; ex: aCH receptors
metabotropic receptors
alter gene expression and internal expression –> use series of secondary messengers
most common type of neurotransmitters
amino acid transmitters
types of amino acid neurotransmitters
glutamate –> widespread excitatory transmitter
AMPA and NMDA receptors
GABA –> widespread inhibitory receptor
iontropic receptors –> inhibitory Cl- channels
types of amine transmitters
acetylcholine, dopamine, seratonin
about acetylcholine
part of cholinergic neurons found in basal forebrain
degradation of these neurons –> associated with Alzheimers
disreuption inferes with learning and memory
dopamine pathways
mesostriatal pathway
mesolimbocortical pathway
mesostriatal pathway
originates at substantia nigra in midbrain –> importnat for motor control –> degradation results in Parkinsons disease
mesolimbocortical pathway
originates in ventral tegmental area; important for learning shaped my positive reinforcement
norepinephrine
controls many behaviors from alertness to mood to sexual behaviors
noradrenegic neurons found in locus coeruleus and lateral tegmental area
serotonin
mood, vision, anxiety, sexual behavior, sleep, etc.
serotonergic neurons originate in raphe nuclei
peptide neurotransmitter types
oxytocin, vasopressin
about peptide hromones
opioid peptides –> reduce perception of pain –> mimic morphine
peptides in gut are made by neurons in spinal cord and brain
oxytocin and vasopressin –> memory and pair bonding
gas neurotransmitters
nitric oxide and carbon monoxide
abnormalities of gas neurotransmitters
produced usually in dendrites (outside axon terminal) and immediately pushed out of neurosn
can immediately diffuse into target cell without transmitter and activate secondary messenger
can be retrograde transmitter –> from postsynaptic neuron to presynaptic neuron
agonist
activates receptor
antagonist
binds but inhibits receptor
binding affinity
degree of attraction between ligand and receptor
efficacy
ability to bound ligand to activate the receptor
dose response curve
relationship between drug doses and the effects
bioavailable
amount of drug that is free to act on the target
biotransformation
produces active metabolites that may produce side effect
blood brain barrier
tight junction between cells of blood vessel in the CNS prevent the movement of large molecules
can limit drug availability –> prevents bigger drugs from entering –> but non polar molecules can still pass easily
metabolic tolerance
organ systems become more effective at eliminating drug
functional tolerance
target tissue may alter sensitivity to durg by altering the number of receptors
down regualtion
in response to an agonist –> less receptor
up regulation
response to an antagonist –> more receptor
cross tolerance
tolerance to one durg is generalized to other drugs
drugs effect on pre synaptic neuron
trasnmitter production
transmitter release
autoreceptors affected
transmitter clearance
drugs effect on postsynaptic neurons
effect transmitter receptors
alter intracellular postsynaptic processes
antispychotics
blocking dopamine receptors to alleviate symtoms of schizophrenia -> block ability to orgasm
atypical antipsychotics
act on other receptors other than d2 receptors –> may relieve symptoms resistant to typical antipsychotics
antidepressants
used to treat disturbances of mood –> affective disorders
monoamine oxidase
inhibitors prevent breakdown of monoamines at synapses
tricyclic antidepressants
block reuptake of serotonin and norepinephrine
selective serotonin reuptake inhibitors
prozac, celexa –> act specifically at serotonergic synapses
anxiolytics
depressants, barbiturates, benzodiazepines
depressants
reduce nervous system activity
barbiturates
early sleep aids that depress nervous –> addictive and easy to overdose on
benzodiazepines
agonist on GABA receptor and enhance their inhibitory effect
opiates
morphine, heroine –> effective analgesic
bidn to opioid receptors in the periaqueductal gray
endogenous opioids
peptides produced in the brain –> enkephalins, endorphins, dynorphins
opioid receptors
delta, kappa, mu –> metabotropic recepotrs
drugs that block these reverse the affects of opioids
chief ingredient in marijuana
delta-9 tetrahydrocannabinol
effects of marijuana
relaxation, mood alterness, stimulation, paranoia
heavy use –> respiratory and cognitive decline
adolescent use –> increased risk of developing schizophrenia
receptors of marijuana
cannabinoid receptors
endocannabinoids –> analogs marijuana produced in brain –> anandamide
stimulants
increase nervous activity –> increase exitatory input and decrease inhibitatory activity
nicotine
stimulant –> increased heart rate, blood pressure, digestive action and alertness
agonist of ACh receptors –> enhance cognitive functin and activate reward/addiction pathway
cocaine
highly addictive –? blood reuptake of monoamine transmitter so their effects are boosted
amphetamine
cause larger than normal release of transmitter at axon temrinals –> interfere with breakdown of transmitter; prolonged use can lead to symptoms like schizophrenia or brain damage
alcohols effects
initial stimulant followed by depressant
GABA and dopamine reward system
fetal alcohol syndrome
prolonge abuse of alcohol = permannent dmagae to fetus; binge drink can cause brain damage and reduce rate of neurogenesis
hallucinogens
alter sensory preception and produce unusual experiences through diverse neural actions
LSD
activates serotonin receptors –> produce mood changes, feelings of creativity and strong visual effects
MDMA
sitmulates visual cortical serotonin receptors –> changes levels fo dopamine and prolactin
logn term use cna cause mood and cognitive issues –> and have long lasting changes in brain activation patterns
major models of drug abuse
moral model
disease model
physical dependence model
positive reward model
addictive drugs
cause dopamine release in nucleus accumbens –> involved in reward pathway
another pathway may involve insula –> damage to this made people stop smoking easily
