I moved to Washington University in St. Louis for my post-doc. This was an amazing time to be at Wash U. The neuroscience community was lead by Max Cowan and included people like Victor Hamburger, Dale Purves, Nigel Daw, Robert Miller, Ed Jones, and Tom Thach, among many others. The infamous Saturday morning seminar program with required attendance for all post-docs and students brought a constant stream national and international leaders of neuroscience to the campus. I started out in Alan Pearlman's lab studying the visual cortex of reeler mice. This project moved very quickly and lead Alan and me to the conclusion that studies on neural cell migration using cell biological techniques were the next important step. Fortunately for us, David Gottlieb was beginning to make monoclonal antibodies to the nervous system so I joined a project making antibodies to chick retina and studied the first monoclonal antibody to the neural cell adhesion molecule (NCAM), quite by accident.
Ray Lund gave me my first faculty position in 1981 in the Anatomy Dept. at the Medical Univ. of South Carolina. While there I made an antibody to NgCAM, the chick homologue of L1. After only two years, I moved with Ray to the Anatomy Dept. at the Univ. of Pittsburgh. Shortly there after Carl Lagenaur joined the dept. and we initiated studies that lead to the demonstration the L1 stimulates axon growth, the first adhesion molecule from brain shown to have this property. We also showed that it does this via a homophilic binding mechanism.
In 1988 I moved to the newly created Neurosciences Dept. at CWRU. With Sue Burden-Gulley and Ross Payne, I began a series of studies on how CAMs influenced growth cone shapes, cytoskeleton and dynamic behavior. One of the most interesting findings was the lack of correlation between adhesive strength and axon behavior. While this is an accepted idea now it was unpopular in some quarters at that time. This result lead us (Eric Wong, Andy Schaefer, Hiroyuki Kamiguchi and Kristin Long) to focus on the L1 cytoplasmic domain in signaling and trafficking. Around 1988 we (Lulu Hlavin and myself) also started a project to clone the human L1 cDNA so we could do structure/function studies. To our surprise and delight, two groups of human geneticists used our cDNA clones to show that mutations in the L1 gene cause a terrible genetic disease, X-linked hydrocephalus. Subsequent studies by Mami Yamasaki and myself revealed a strong correlation between the type of mutation and the severity of the disease. It also confirmed the notion that the L1 cytoplasmic domain plays an essential role in axon growth and guidance. While at CWRU I was very lucky to work with Gary Landreth and Urs Rutishauser.