slides Flashcards
What are the 9 steps of neurtransmission?
(1) NTs are synthesized in vesicles in pre-synaptic cell (2) AP reaches presynaptic terminal
(3) Ca2+ channels open because of depolarization
(4) Ca2+ flood presynaptic cell
(5) vesicles containing NTs fuse to the cell wall
(6) NTs released into the cleft via exocytosis
(7) NTs bind ot receptors on the post-synaptic cell
(8) channels on the post-synaptic cell either open/close (9) inhibitory/excitatory signal is sent in the post-synaptic cell
What is an agonist?
a ligand that binds to a receptor and mimics the effects of a NT
includes both molecular and behavioral changes
What is an antagonist?
a ligand that binds to a receptor and blocks the binding of a NT
does not include molecular change, but does have behavioral changes
for example, caffeine
What is tolerance/cross-tolerance?
when the body, over the timecourse of drug administration, slowly needs more and more of the drug to have an effect
cross-tolerance refers to the ability of one drug to cause tolerance for another drug
for example, alcohol and cocaine/amphetamine
What is sensitization/cross-sensitization?
when the body needs less of a drug over time to have the same effect, the effects become stronger with the same doseage
cross-sensitization refers to the ability of a drug to also cause sensitization for another drug
What does pharmacokinetic refer to?
refers to everything that happens in the body before/ after the drug reaches the recpetor
kinetic = movement
for example, how the body transfers, reabsorbs, inactivates and excretes the drug
also, half -life research falls under this umbrella
What does pharmacodynamic refer to?
this is what happens when the drug takes action at a site
for example, both physiological and biochemical interactions of the drug at a site
like caffeine being an antagonist at a a recpetor site
What does the elevated plus maze model?
What does an animal do once given the (targeted) medication?
anxiety model
if a rat is given anti-anxiety medicaiton, they will spend more time in the open arms of the maze
What does the conditioned place preference procedure model?
What does an animal do once given the (targeted) medication?
drug addiction model
if a drug with highly addictive properties is administed in one room, then the rat is more likely to spend time in that room because of the associated positive stimuli (even if that stimuli is no longer there)
What does the animal self-administration procedure model?
What does an animal do once given the (targeted) medication?
drug addiction model
if a drug with more addictive properties is adminstered, the lab rat is more liekely to self-administer often
depending on how many times the rat presses a lever, they will recieve different doses
a progresive ration model (more presses are required for drug distribution over time) can help model a drugs ‘breaking point’ (when the costs outweigh the benefits)
What does the pre-pulse inhibition (PPI) model?
What does an animal do once given the (targeted) medication?
schizophrenia/neuroleptic model
if a person has schizophrenia, they will have decreased PPI after given a cue that a startle stimuli will be presented (they will be just as startled even if they know the stimuli is coming)
if a neuroleptic is effective, it should increase PPI (less startled)
What does the learned-helplessness procedure model?
What does an animal do once given the (targeted) medication?
depression model
if anti-depressants are effective, the dog should be more willing to try and escape shocks that the previously would not have avoided (because of learned-helplessness they developed from not being able to escape initially)
if a dog is depressed, they will give up more quickly on trying to avoid shocks
What does the 8-arm-raidal maze and the Morris water maze model?
What does an animal do once given the (targeted) medication?
memory and cognitive function model
if a drug improves memory and cognitive function, a lab rat will be able to find the correct arm of the maze/platform in the water more quickly
if an animal has cognitive or emmeory impairments, they will be slower
(1) What kind of molecule is glutamate?
(2) Which kinds of cells contain glutamate?
(3) What is the role of glutamate?
(4) What is the precursor to glutamate?
(5) What enzyme synthesizes glutamate from its precursor?
(6) Where is glutamate found in the brain?
(1) excitatory amino acid NT
(2) glial cells and all neurons contain glutamate
(3) has 2 main functions: excitatory NT to excite post-synaptic cell, protein synthesis/ metabolism
(4) glutamine
(5) glutaminase
(6) everywhere - because it has 2 very important functions
What is unique to the glutamate neuron-astrocyte interaction?
Why?
Glutamate is synthesized from glutamine by glutaminase in the presynaptic cell
it is then released into the cleft and binds ot receptors on the post-synaptic cell
after it is released into the cleft, astrocytes recycle the glutamate by deactivating it back into glutamine (with glutamine synthetase)
glutmaine transporters then transport glutamine back into the pre-synaptic cell
this system is important because glutamate is an excitatory NT that needs to be deactivated quickly, or the post-synaptic cell will keep being excited
(1) What are the 2 glutamate receptors?
(2) What is important about the way these 2 receptors work together?
(1) NMDA and AMPA
(2) NMDA is an ion channel that needs 2 NTs to open: glutamate and glycine/D-serine
NMDA is often blocked by magnesium that is released if the membrane is previously activated (depolarized)
this prior activation which releases the magnesium is only possible due to AMPA receptors
NMDA also acts as a Ca2+ channel to activate 2nd messenger systems
What is Long Term Potentiation (LTP)?
How is it relevant to the glutamate receptor systems?
(1) when a signal is sent frequently enough, there are long lasting increases in the signal transmission between 2 neurons
(2) in the glutamate receptor system, NMDA is relevant during short-term/acute glutamate transmission
however, once 2nd messenger systems are activated (thanks to the Ca2+), NMDA is less relevant
for example, glutamate release can now be increased from the pre-synaptic cell, AMPA receptors are up-regulated, and AMPA receptors are now more sensitive to glutamate
(1) What kind of molecule is GABA?
(2) Where is GABA found in the brain and what is its role there?
(3) What is the precursor to GABA?
(4) What enzyme synthesizes GABA from its precursor?
(1) inhibitory NT
(2) most often found in: substantia nigra/ dopamine inhibition, cortex/ glutamate inhibition, hippocampus/glutamate inhibition
overall, it is expressed more highly than other NTs in the cortex/ most prominent
(3) glutamate
(4) GAD, glutamic acid decarboxylase
What are 2 GABA receptors and what kind of receptors are they?
1) GABA- A /ionotropic
2) GABA-B/ metabotropic
we focus mostly on GABA-A
(1) What is GABA-A mostly a target for?
(2) What kind of channel is it?
(3) What molecule is it a channel for?
(1) psychoactive drugs: like benzodiazepines and barbiturates
(2) ionotropic
(3) chloride channel