Posted by SLS on May 19, 2003, at 7:52:52
In reply to Re: Scott's 100% right » Jack Smith, posted by ace on May 19, 2003, at 3:10:02
I don't know about 100%!
> ...those anecdotes mean little. Biochemically, a fifth trial works as good as a first trial.
The drug might be doing exactly the same thing, but the body reacts differently, sort of like the immune system reacts to an antigen.
Here's my poorly-described proposed example:
During the first exposure to a drug, a series of events in the postsynaptic neuron, ie. a cascade of second messenger events, turn on genes within the nucleus to change the expression of enzymes and surface receptors. At some point, however, this machinery reaches a new equilibrium. A new dynamic balance is reached between drug effects and biological reactions to them. When the drug is discontinued, the cellular machinery and enzyme systems remain changed relative to that which existed previous to its first exposure to the drug. In other words, the system is no longer "naive" to the actions of the drug. The next time these neurons are subject to the drug, the response travels along a somewhat altered biological path, whether it be chemical or temporal. The equilibrium is therefore reached at a different position relative to the first one.
- Scott
poster:SLS
thread:226476
URL: http://www.dr-bob.org/babble/20030514/msgs/227598.html