Posted by cybercafe on July 18, 2002, at 13:14:52
In reply to Correction Last Post, posted by hawkeye on July 18, 2002, at 6:29:37
>and the cytopiasm within the neuron, a condition that biocks the ability of a neuron to fire and to release its transmitter. It has been reported
actually i think depolarization occurs when sodium or calium or other positively charged ions diffuse across a potential different (polarization) and therefore reduce the polarization (depolarization)... this causes neurons to fire! ... however what makes things a bit more complicated is that as the neurons fire i believe sodium channels close to limit just how depolarized the cell gets... and then instead of getting rid of these positive Na ions, we pump out potassium K ions... since Na ions are in a greater concentration outside the cell they would have to be actively PUMPED out.. whereas since K ions are at a greater concentration INSIDE the cell, we can just let them DIFFUSE out... (much faster)....
basically sodium channels close after a certain amount of sodium enters the cell, so that too much sodium doesn't enter the cell (because the concentration inside the cell is always carefully maintained at about one tenth of the concentration outside the cell).... and for the neuron to fire again, these channels have to open again! ... also you have to wait for the time it takes for the potassium to be pumped out of the cell ....so basically when a cell fires, it lots of positive ions on the inside and becomes positive, in order for it to fire again it has to become negative again, and so you have to pump out the ions that made it positive.. this takes time.... depending on how long this takes, and how you alter the time it takes, by causing a cell to fire you are making it harder for it to fire again.... so in a way the firing of XXX neurons causes a decrease in the firing of XXX neurons
>believe that there is no reason to think that depolarization represents a return to the normal state of the dopamine system, and they conclude that there is probably nothing at all wrong with the dopamine system in schizophrenics."
wait a sec here ....
depolarization = not a normal dopamine system
schizophrenic treatment = provide for not a normal dopamine system (change their dopamine system)
changing schizophrenic dopamine system = therapeutic effectsso if changing the system results in therapeutic effects....
if
old system = problems
new system = problems solvedthen why would you say that there is nothing wrong with the dopamine system in schizophrenics?
poster:cybercafe
thread:112626
URL: http://www.dr-bob.org/babble/20020718/msgs/112793.html