The adhesive role of acetylcholinesterase (AChE): detection of AChE binding proteins in developing rat spinal cord.

Acetylcholinesterase (AChE) is expressed by dorsal root ganglion (DRG) neurons during developmental periods when their central axons are growing into and through the spinal cord. Importantly, our previous studies have shown that AChE induces DRG axonal outgrowth by an adhesive mechanism and thus, have now employed a blot overlay technique to screen for potential AChE binding proteins in the developing spinal cord. Our results show that: (1) AChE binds to proteins with apparent molecular weights of 200, 110, 35, and 33 kDa; (2) these proteins are developmentally expressed during periods of axonal outgrowth from DRG neurons; (3) all four proteins are synthesized by astrocytes; and (4) AChE binding to these proteins is highly dependent on ionic strength supporting an electrostatic mechanism of adhesion. Taken together, these data provide further documentation for the participation of AChE in adhesive interactions during morphogenesis of the central nervous system and suggest a role for astrocytes in regulating AChE-mediated axonal growth.