Mechanism of anoxic depolarization in the brain intracellular Na and Ca ions, and extracellular glutamate and aspartate. Glutamate and aspartate are normally present as the brain's primary excitatory neurotransmitters, but high concentrations activate a number of downstream apoptotic and necrotic pathways. This results in neuronal dysfunction and death. Neurons function in the central nervous system by generating signals from synapses, and this only works in the proper chemical environment. An electrical signal is mediated by the sodium channels and leaky potassium channels in which intracellular K ion concentration is higher than its corresponding extracellular concentration, whereas extracellular concentrations of Na, Ca, and Cl ions are higher than
The Stealers of Dreams typical. Then the Doctor is there, and asks to talk to him, go into the building and try to help. Once the Doctor gets inside, Jack fills him in on what's happening. Rose is in a room, still unsure of herself. The Doctor tells her about the microorganisms, how they feed off electrical activity, and seem to just love the neuroelectro-chemical signals put out by the right side of adult human brains. They create a feedback loop, which passes to the left side and causes a person to become 'fantasy-crazy.' He tells her that now that she understands what is