I started blogging in order to share some of my experiences as the brother of a severely autistic, low functioning and nonverbal person. I grew up in a time where little was known about autism and there was very little support available in the community for autistic individuals, their siblings or their parents. I was lucky enough to be brought up in an atmosphere where questions were encouraged.
Having a brother who was so totally unable to communicate got me thinking about the nature of all kinds of things: what is a human being?; why is my brother the way he is?
The latter question sparked my interest in the workings of the brain. During my years working in a hospital setting, I was fortunate to meet and work with Dr. Andrew Lautin, Clinical Professor of Psychiatry, who had just completed a volume about the limbic system (The Limbic System, New York: Kluwer Academic Publishers 2001). We are currently working on an introductory neuroanatomy text, using simple concepts to explain the development and organization of the human brain.
Today, I would like to mention the work of Wilhelm His. His work is key to the central concept of our book: modeling the central nervous system (brain and spinal cord) as a flexible rubber tube. From Stephen Jay Gould:
“In his greatest work of 1874, Unsere Koperform und das physiologische Problem ihrer Entstehung, His noted the extraordinary resemblance between embryonic organs and simple manipulation upon rubber tubes. We must start from the fact that the brain at its beginning stages, is a [hollow] tube with moderately elastic walls.” Stephen J. Gould, Ontogeny and Phylogeny, Belknap/Harvard, 1977 (pg. 189)
His displayed several figures of early stages of the neural tube of a chick embryo side-by-side with a rubber tube model. He attached strings to places on the rubber tube, which, when pulled upon, deformed the rubber tube to approximate the shape of the embryo. He went on to say:
“These examples, may be sufficient to prove the general importance of elementary mechanical considerations in treating morphological questions. They show at the same time how the means that nature uses in forming her organisms may be very simple. The segmented germ [embryo] divides itself into primitive embryonic organs by a few systems of folding . . . Even the most complicated of our organic systems, the nervous system, follows a course of the most astonishing simplicity” (Wilhelm His, 1888 from Stephen J. Gould, Ontogeny and Phylogeny, Belknap/Harvard, 1977 pg. 190)
The fact that mere physical forces could deform an embryo into familiar embryonic forms flew in the face of the Ernst Haeckel‘s biogenetic law: Ontogeny recapitulates phylogeny. This theory stated that in the development of the human embryo, all previous evolutionary stages must be repeated. This is an interesting controversy, but not central to our goal. The fact that we are interested in is that a mechanical can accurately represent the morphology of different stages of the development of the neural tube (that structure that underlies the central nervous system from spinal cord to cerebral cortex).
Once we establish that the inner core of the central nervous system can be modeled after a flexible rubber tube balloon, it is a short step to demonstrating that a party entertainer, skilled in making animal forms out of a balloon, can squeeze and twist one into a human brain.