Posted by T_R_D on May 13, 2004, at 12:28:01
In reply to Calcium homeostasis Mood disorders, posted by Civ on May 11, 2004, at 13:38:50
Okay, this is very "layman" and possibly incorrect...chemist can enlighten us if I am off base.
Neurologically speaking, neurons fire by the opening of sodium channels and the closing of potassium channels. These electron (charged particles) and chemical changes cause an action potential (spike of electrical activity) within the brain. The firing continues in a chain-like fashion between cells until the desired result is achieved.
What some anticonvulsants do (although chemist is right--poorly understood so they are "suggested" to do) is block the calcium channels in the brain so this little exchange can not happen. This effectively controls epilepsy which are "electrical storms" of neurons firing within the brain.
It is presumed that by somehow stopping the firing in bipolar patients mood is improved. Particulary in removing mania. I like to think that mania is like mini electrical storms that affect one's moods--not just the physical aspect of our bodies. That's just my imagination hard at work though :)
There are all sorts of theoretical links beween epilepsy and bipolar (comorbid condtions in a sample of the population) and I myself have suffered from (undiagnosed) simple partial seizures.
Not all anticonvulsants work this way, however. Gabapentin/Neurontin increases the levels of GABA (gamma aminobutyric acid) within the brain. The role of GABA is a different thing altogether.
One of the main functions of GABA is to control voluntary movement in the limbic system etc... This is obviously not the desired effect for bipolar. It also works in the creation of action potentials in conjunction with other excitatory/inhibitory neotransmitters (eg. glutamate, dopamine.) An increase in one collection will achieve the desired affect (either excitatory--making soemthing happen or inhibitory--stopping something from happening.) They can also cancel each other out making nothing happen.
I think GABA has an overall calming effect so it works similarly to serotonin. We must remeber that neurotransmitters do all sorts of things apart from mood stabilization. Many things that haven't even been discovered yet!
So that's a basic overview of neuroanatomy and physiology 101! Does that help at all?