Lectures 19-22(only first 3 slides) Flashcards
What happens in the 4th step (signaling) of neurotransmission?
The presence of neurotransmitters are detected by neurotransmitter receptors
What are receptors made up of and what 4 important characteristics do they have?
HINT for characteristics: amines, classical neurotransmitters, 1 for 1, (abc;123;…;…)
Made up of membrane protein complexes
1) different signals for same receptor=different reaction
2) Neurotransmitter’s are made for specific receptors (1for1)
3) Most Nts have multiple receptor subtypes (classical neurotransmitter,amino acid)
4) all different naming rules
What are the 5 different naming rules for receptors we learned?
1) alphabetical subscripts : GABA(a)
2) numerical subscripts: Dopamine: D(1),D(2)
3) named by drugs that active them: nicotinic-(acetylcholine)
4) named be roman numerals: Glutamate
5) some named by NT and some named by drug: Glutamate- canate receptor(drug)
What are the 2 general classes of receptors and how do they differentiate?
Differentiated by type of signalling
1) Ionotropic- does so through ion channel, changes membrane
2) Metabotropic- initiate cascade of chemical events
What is an ionotropic receptor and it’s 3 characteristics? keep it sweet and …
Has ion channel and changes the membrane, known as fast transmission
1) Direct-really fast
2) rapid onset
3) short lived
How does an ionotropic receptor function, 3 stages(2. possibility’s of channels)
1) Allow ion flow through channel in response to neurotransmitter
ONE OF TWO WAYS IT CAN GO
2) IF sodium or calcium channel opens causes depolarization(exciting, closer to an action potential) (influx-rushes into cell)
IF Potassium or chloride channel open causes hyperpolarization by potassium or chloride flowing out of cell
What are the 3 functional domains (parts) of ionotropic receptors and there functions?detector selector, common ground
1) ligand binding-detects Neurotransmitter
2) Pore-ion channel
3) Ion selectivity filter- channel selects neurotransmitter
What is the ion selectivity filter made up of and what are the 3 characteristics of that particular make up?
Made from multiple protein sub units
3 characteristics for sub units:
1) many different alleles, functions vary
2) Clinically significant in human disorder s
3) Characteristics may vary sub unit to sub unit
What are the 4 important things to remember about metabotropic receptors and what do they initiate?
initiate cascade of chemical events
4 things to remember
1) G proteins
2) effector molecules
3) second messenger
4) mediators
What are the 4 steps in metabotropic receptors (tickling)
1) metabotropic receptors bind to NT
2) tickles G protein and has impact on effector molecule
3) produces a 2nd messenger:(whatever molecule the effector ended up making after touching G Protein. Changes in amount of concentration too)
4) Mediator alters activity in molecule then mediates with substrates
Who is the 1st,2nd and “third” messenger in metabotropic receptor processes? (like three step drama)
1st messenger: Neurotransmitter
2nd messenger: Effector molecule after G protein touches it and changes concentration
“3rd messenger”: mediator; who 2nd messenger interacts with after
Overall, What does receptor activation lead to? (changes in…) M
Leads to changes in the activity of mediator enzymes
5 Processes altered by mediator enzymes: CCOGS
1) cell physiology/ structure
2) channels
3) other enzymes
4) Genes
5) structural proteins
What are the 3 features of Metabotropic receptors?
1) Indirect
2) Slow on set
3) long lived
What two kinds of “transmissions” (one each) do we use to refer to 1) metabotropic receptors 2) Ionotropic receptors? Think about the different features of both receptors…
Metabotropic receptors- known as slow transmission as they are long living
Ionotropic receptors- Known as fast transmission as they are short lived
Why are metabotropic receptors amplified? HINT: Why is its process so slow…?
Due to all the steps it must take, but increases amount of product each step resulting in 100’s of substrates in end.
For reference: 1 NT turns into 5 G proteins, 5 G proteins to 5 effector molecules, 5 effectors into 50 2nd messengers, 50 2nd messengers into 50+ mediators, 50+ mediators into 100s of substrates
SHORTENED FORM:
1 turns to 5
5 turns to 50
50 turns to 50+
50+ turns into 100’s
What is the structure of a metabotropic receptor? (1) And it’s 2 domains? chicken and talking…
structure: 1 protein
1) Nt interactions
2) G protein interactions
What is the 5th step of neurotransmission and its use?
Termination of actions, What neurons use to end a message
What are the two processes your able to use to terminate actions in step 5 of neurotransmission? SEND ER UP
BREAK ER DOWN
1) re uptake: remove NT from synapse with re uptake transporter (synaptic transporter)
2) Degradation: destroys NT using catalytic enzymes and many steps
What is a synaptic transporters use and what is catalysis/catalyzing use? HINT: catastrophe, moving things back up into..
Synaptic transporter: re up take (bring up) Neurotransmitters into cell from synapse
Catalysis: Breaking things down
What is synaptic transmission? nt going opposite sides…
Nt is released at synapse, travels across synaptic cleft to interact with receptor directly across in post synaptic cell
What is a neuromodulater and what 3 ways do we confirm if it is an neuromodulater? (travels, odd big travels)
def: Neurotransmitters working in a different way than usual
1) Travels far away from site of release to perform effects
2) Modulates effects of neurotransmission at other synapses
3) volume transmission
3 Steps in neuromodulation
(transforming NT) , what two things does it effect/change …
1) NT is released
2) Has Actions further away from synapse; turns into neuromodulater
3) neuromodulater then has effects that modulate how cell responds to different NT’s and different synapses
What 2 types of receptors are found in Pre synaptic terminal and what do they do?
Autoreceptors- function as feed back loop: has info about how much NT is being released/ still floating around
Heteroreceptors: another anme for axoaxomic synapses: between 1 axon and another, CAN CAUSE hyper or de polarization
What does integration (summation) do and what is the spontaneous firing rate? (the judges, random decisions)
Integration: Judges when to fire Action Potential based off of all relevant post synaptic activity.
Spontaneous firing rats: Firing of an action potential every once in a bit, Without synaptic input
What are the 2 Types of Post synaptic events and what do they do? (movement, changes, think metabotropic features)
1) Post synaptic potentials- allow ion movements into or out of cell that cause changes in membrane potential
2) change in enzyme activity’s- creates diverse indirect long lasting effects on neuronal structure/function
In the 2 types of post synaptic events (post synaptic potentials and changes in enzymes) what receptor (metabotropic or ionotropic) does each bind with or initiate from?
Post synaptic potentials:
initiate indirectly from metabotropic or directly with ionotropic
Changes in enzymes: initiated my metabotropic receptor activation
What are the 2 types of post synaptic potentials and what happens during them? yay!! EXCITING, IN the depths) opposites
1) excitatory post synaptic potential: Post synaptic de polarization(becomes more positive) -closer to firing A.P (very exciting!!)
2) inhibitory post synaptic potential : post synaptic hyper polarization, becomes more negative and farther from firing A.P
What are excitatory psps and inhibitory psps caused by? (1 of two things for each)
1) Excitatory:caused by influx (flowing into cell) in Sodium or Calcium
2) Inhibitory: Caused by influx in Chloride (flowing into cell) or efflux or Potassium (flowing out of cell)
What are the 2 ways Post synaptic potential differ from action potentials and explain? (I’m going to get a good grade.., the evil queen in bowls moving castle )
1) Graded potentials- psps vary in intensity; can have different grades. A.ps are all or nothing law
2) not self propagating- diminish in strength as travelling away from site of initiation
4 Steps of integration/summation
THE JUDGES whether or not…
1) adding up activity in synapses within comparable time period
2) Factoring in how far away from one another
3) seeing how everything summates(adds up) to fire A.P
4) resulting in change in membrane potential in axon hillock
What is the spatial summation principal and temporal summation principal?
(the decision makers, double the team,double the …)
Spatial summation:
Synapses closer to axon hillock have bigger decision on whether or not to fire action potential compared to synapses further away from axon hillock
Temporal summation:
the closer the two synapses (temporal threshold) are in activity the bigger the total effect
What is pharmacology and what’s a drug? (altering of … for drug )
Pharmco: Study of effect on drugs on living things
-Any chemical or combo of chemicals that alter biological function, structure when administered. EXCEPT those for normal health maintenace
What are psychoactive drugs and what’s their purpose? (goes back in a loop)
alters thoughts feelings actions, to change thoughts feelings actions
What are the 2 ways drugs affect synaptic transmission? (think two characters in a storybook and what they do)
Antagonist- decrease activity in synapse
agonist- increase activity in synapse
