Posted by phidippus on September 16, 2012, at 14:08:30
In reply to Re: Pristiq dosages of 200 - 400 mg/day. » phidippus, posted by SLS on September 15, 2012, at 19:34:45
"Excessive glutamate, or excitotoxins acting on the same glutamate receptors, overactivate glutamate receptors (specifically NMDARs), causing high levels of calcium ions (Ca2+) to influx into the postsynaptic cell. High Ca2+ concentrations activate a cascade of cell degradation processes involving proteases, lipases, nitric oxide synthase, and a number of enzymes that damage cell structures often to the point of cell death. Ingestion of or exposure to excitotoxins that act on glutamate receptors can induce excitotoxicity and cause toxic effects on the central nervous system.
In the case of traumatic brain injury or cerebral ischemia (e.g. cerebral infarction or hemorrhage), acute neurodegeneration caused by excitotoxicity may spread to proximal neurons through two processes. Hypoxia and hypoglycemia trigger bioenergetic failure; mitochondria stop producing ATP energy. Na+/K+-ATPase can no longer maintain sodium/potassium ion concentration gradients across the plasma membrane. Glutamate transporters (EAATs), which use the Na+/K+ gradient, reverse glutamate transport (efflux) in affected neurons and astrocytes, and depolarization increases downstream synaptic release of glutamate"
Eric
poster:phidippus
thread:1024121
URL: http://www.dr-bob.org/babble/20120912/msgs/1025805.html