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
Evolution of the brain the structures responsible for basic behaviors. A long term human study comparing the human brain to the primitive brain found that the modern human brain contains the primitive hindbrain region – what most neuroscientists call the protoreptilian brain. The purpose of this part of the brain is to sustain fundamental homeostatic functions. The pons and medulla are major structures found there. A new region of the brain developed in mammals about 250 million years after the appearance of the hindbrain. This region is known as the paleomammalian brain, the major parts of which are the hippocampi and amygdalas, often referred