What Brains Are Made Of

Abstract

All brains are surprisingly similar. Once one has seen histologic preparations of human brain under the microscope, one will have no trouble recognizing nerve tissue of other animals even in species that are only very distantly related to us, such as squids or insects. I shall try to give a general characterization of nerve tissue.

The fine structure of the grey substance of the brain is not the same all over. Basically, it consists of nerve fibers… of strange granula, of ganglion cells, and of an apparently homogenous, structureless molecular mass, an unusually fine network, in which the finest terminations of the white nerve fibers and the ramifications of the ganglion-cell processes dissolve.

Griesinger, 1861 [4.3]

… Most likely these millions of cells are connected with one another.

Krafft-Ebing, 1897 [4.6]

The more one finds out about properties of different synapses, the less grows one’s inclination to make general statements about their mode of action.

Katz, 1966 [4.5]