Origin of Mind in the Brain.
The nervous system in vertebrates was analyzed focusing in published controversies on structure and function concerning neurons and neuroglia cells and their roles in perception, thoughts, intuition, feelings and will, as well as the conscience and subconscious structures origin of signals that link human beings with the environment. The teleost retina of Mugil brasiliensis used as model, was fixed in glutaraldehyde and osmium tetroxide, stained with lead citrate and uranyl acetate and analyzed in a Hitachi-11B electron microscope at 75 Kv. To demonstrate glycogen, fragments glutaraldehyde fixed osmium post-fixed were sectioned in the MT2 ultramicrotome and processed with periodic acid thiosemicarbizide for oxidized molecules.Electric synapses with Na+K+ ATPase were more numerous than chemical synapses and were analyzed in their role for transmission of the electrical potential in neurons and neuroglia. The evolution of the nervous system from insects to human beings is presented in its relations with thought, memory and mind.