DEFICIENT LAR EXPRESSION DECREASES BASAL FOREBRAIN CHOLINERGIC NEURONAL SIZE AND HIPPOCAMPAL CHOLINERGIC INNERVATION

A role in neural development for protein tyrosine phosphatase (PTPase) receptors has been suggested by the finding of aberrant neurite outgr owth in Drosophila mutants lacking functional leukocyte common antigen -related (LAR) PTPase receptors; however, PTPase functions in the mamm alian nervous system remain to be established, In transgenic mice cont aining a gene trap in the LAR gene, only trace expression of full-leng th LAR transcripts was found, In these mice, the size of basal forebra in cholinergic neurons was significantly reduced and cholinergic inner vation of the dentate gyrus was markedly decreased, These findings con stitute the first demonstration of an aberrant neuronal phenotype in a mammalian PTPase mutant and support the hypothesis that LAR-type PTPa se receptors function to establish and/or maintain neuronal networks. (C) 1997 Wiley-Liss, Inc.