A novel role for embigin to promote sprouting of motor nerve terminals at the neuromuscular junction.

Adult skeletal muscle accepts ectopic innervation by foreign motor axons only after section of its own nerve, suggesting that the formation of new neuromuscular junctions is promoted by muscle denervation. With the aim to identify new proteins involved in neuromuscular junction formation we performed an mRNA differential display on innervated versus denervated adult rat muscles. We identified transcripts encoding embigin, a transmembrane protein of the immunoglobulin superfamily (IgSF) class of cell adhesion molecules to be strongly regulated by the state of innervation.

Effects of Abeta1-42 fibrils and of the tetrapeptide Pr-IIGL on the phosphorylation state of the tau-protein and on the alpha7 nicotinic acetylcholine receptor in vitro.

In order to investigate the possible links connecting beta-amyloid (Abeta) accumulation, tau-hyperphosphorylation and nicotinic receptor expression, rat embryonic primary hippocampal cultures were incubated with amyloidogenic peptides. Exposure to 0.5 microm fibrillar Abeta(1-42) for 3 days caused retraction of dendrites, shrinkage of cell bodies and a decrease in the expression of microtubule-associated proteins 2b (MAP2b), without affecting the total number of neurons and their viability.