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Quote: from Its Bearsy Bitch at 3:11 am on Aug. 29, 2008

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yeah I know stuff gets blocked, but how is the cocaine doing this?! Are there little pieces of powdered cocaine sitting in the doorway of the dopamine receptors? Like literally the powder is sitting there and dopamine is bumping into a big wall of cocaine it can't get through?

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Cocaine can bind to the receptors on the post synaptic membrane (like a door). It prevents the dopamine, adrenaline, etc, from accessing this door and hence cannot pass into the other side, so they remain in the synaptic cleft. If this prevents enough neurotransmitter from travelling across the synaptic cleft it can prevent the opening of the sodium ion channels, preventing an action potential because the minimum voltage is not met, and hence the impulse is not propagated.

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Actually, that's not the case. The dopamine receptors are unaffected. What is being fucked with is the dopamine transporters which bring baby catecholamine home to sleep for the night.

The net result is a greater and prolonged post-synaptic potential, which means an increased chance of action potential.

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"My name is Ozymandias, King of Kings:
Look on my works, ye Mighty, and despair!"

Ok I'm understanding better now I believe thank you sir.  

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click and please click
^use head phones

the chunks of cocaine are blockingthe door of this thing

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click and please click
^use head phones

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Quote: from marshmellowman at 10:16 pm on Aug. 28, 2008

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Quote: from Its Bearsy Bitch at 3:11 am on Aug. 29, 2008

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yeah I know stuff gets blocked, but how is the cocaine doing this?! Are there little pieces of powdered cocaine sitting in the doorway of the dopamine receptors? Like literally the powder is sitting there and dopamine is bumping into a big wall of cocaine it can't get through?

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Cocaine can bind to the receptors on the post synaptic membrane (like a door). It prevents the dopamine, adrenaline, etc, from accessing this door and hence cannot pass into the other side, so they remain in the synaptic cleft. If this prevents enough neurotransmitter from travelling across the synaptic cleft it can prevent the opening of the sodium ion channels, preventing an action potential because the minimum voltage is not met, and hence the impulse is not propagated.

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Actually, that's not the case. The dopamine receptors are unaffected. What is being fucked with is the dopamine transporters which bring baby catecholamine home to sleep for the night.

The net result is a greater and prolonged post-synaptic potential, which means an increased chance of action potential.

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Haha, I like your euphemism.

So, it's the opposite to what I described then, rather than less impulses resulting, you end up with more impulses.

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and victorious in war shall be made glorious in peace.

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So it is in fact that the dopamine are locked out because a very small piece of cocaine is in their way, and the cocaine is physically blocking the door... because the dopamine is even smaller than the cocaine molecule  

Ok I'm understanding better now I believe thank you sir.  

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It doesn't matter what is smaller or bigger.

If we're talking competitive inhibition, a functional group or several functional groups on the cocaine are very structurally similar in their layout to the equivalent area on the dopamine. That means that it would snugly fit into the relevant site on the transporter protein.

When the dopamine randomly swims up, instead of sliding into the spot it doesn't, because there isn't anything to fit into. It is blocked. It doesn't matter how big the car that took your parking space is, you're not getting into that spot.

With non-competitive inhibition, the size would be irrelevant. In that case, the cocaine would actually change the shape of the transporter molecule and as a result, dopamine can't fit anymore. The size of the parking spot has been changed, and also maybe now it is a triangle.

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"My name is Ozymandias, King of Kings:
Look on my works, ye Mighty, and despair!"

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So, it's the opposite to what I described then, rather than less impulses resulting, you end up with more impulses.

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Righty-o.

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"My name is Ozymandias, King of Kings:
Look on my works, ye Mighty, and despair!"

the molecules of cocaine are shaped so funny no one can get in

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click and please click
^use head phones

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I have a picture you guys:  

the chunks of cocaine are blockingthe door of this thing

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sooo  

the molecules of cocaine are shaped so funny no one can get in

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Okay, imagine a doorknob with a keyhole.

One key unlocks the door (Key 1), but many keys might be able to be inserted.

Put a key that doesn't unlock it into the door.

Without removing that key, can you now unlock the door with Key 1?

That is what is happening. It is a similar enough shape so as to get in, but different enough so that nothing happens, and the real key finds that its seat on the bus is taken.

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"My name is Ozymandias, King of Kings:
Look on my works, ye Mighty, and despair!"

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Quote: from Its Bearsy Bitch at 10:21 pm on Aug. 28, 2008

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So it is in fact that the dopamine are locked out because a very small piece of cocaine is in their way, and the cocaine is physically blocking the door... because the dopamine is even smaller than the cocaine molecule    

Ok I'm understanding better now I believe thank you sir.  

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It doesn't matter what is smaller or bigger.  

If we're talking competitive inhibition, a functional group or several functional groups on the cocaine are very structurally similar in their layout to the equivalent area on the dopamine. That means that it would snugly fit into the relevant site on the transporter protein.  

When the dopamine randomly swims up, instead of sliding into the spot it doesn't, because there isn't anything to fit into. It is blocked. It doesn't matter how big the car that took your parking space is, you're not getting into that spot.  

With non-competitive inhibition, the size would be irrelevant. In that case, the cocaine would actually change the shape of the transporter molecule and as a result, dopamine can't fit anymore. The size of the parking spot has been changed, and also maybe now it is a triangle.

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What if your parking space is blocked by empty boxes, no problem  

I think it would have to be a certain size.  

I'm getting confused though. could two types of molecules be the same shape ever?

Post edited at 7:33 pm on Aug. 28, 2008 by Bearsy

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click and please click
^use head phones

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Quote: from Its Bearsy Bitch at 10:26 pm on Aug. 28, 2008

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sooo

 the molecules of cocaine are shaped so funny no one can get in

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Okay, imagine a doorknob with a keyhole.

One key unlocks the door (Key 1), but many keys might be able to be inserted.

Put a key that doesn't unlock it into the door.

Without removing that key, can you now unlock the door with Key 1?

That is what is happening. It is a similar enough shape so as to get in, but different enough so that nothing happens, and the real key finds that its seat on the bus is taken.

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Yeah it makes fine sense... so it is only one cocaine molecule in the door or it is multiple

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click and please click
^use head phones

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Quote: from TheOtherHorseman at 7:28 pm on Aug. 28, 2008

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Quote: from Its Bearsy Bitch at 10:26 pm on Aug. 28, 2008

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sooo    

  the molecules of cocaine are shaped so funny no one can get in

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 Okay, imagine a doorknob with a keyhole.  

 One key unlocks the door (Key 1), but many keys might be able to be inserted.  

 Put a key that doesn't unlock it into the door.  

 Without removing that key, can you now unlock the door with Key 1?  

 That is what is happening. It is a similar enough shape so as to get in, but different enough so that nothing happens, and the real key finds that its seat on the bus is taken.

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Oh right, right.  

Yeah it makes fine sense... so it is only one cocaine molecule in the door or it is multiple

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It only takes one. If it helps you to envision it, cocaine IS bigger. (the relative size is still irrelevant here, though)

DOPAMINE

COCAINE AGAIN

Post edited at 7:37 pm on Aug. 28, 2008 by TheOtherHorseman

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"My name is Ozymandias, King of Kings:
Look on my works, ye Mighty, and despair!"

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What if your parking space is blocked by empty boxes, no problem  

I think it would have to be a certain size.  

I'm getting confused though. could two molecules be the same shape ever?

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Quote: from Its Bearsy Bitch at 3:31 am on Aug. 29, 2008

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What if your parking space is blocked by empty boxes, no problem

 I think it would have to be a certain size.

 I'm getting confused though. could two molecules be the same shape ever?
 

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Well it'd just have to be similar enough to fit into the active site and form bonds with the active site (so not 'fall out'), but can have like one or two different functional groups which means it stays there but does nothing. Picture from wikipedia below:

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It doesn't matter what the rest of the key looks like, just the important part with all the ridges and such.

-------
"My name is Ozymandias, King of Kings:
Look on my works, ye Mighty, and despair!"