Molecular mechanisms that enhance synapse stability despite persistent disruption of the spectrin/ankyrin/microtubule cytoskeleton.

Loss of spectrin or ankyrin in the presynaptic motoneuron disrupts the synaptic microtubule cytoskeleton and leads to disassembly of the neuromuscular junction (NMJ). Here, we demonstrate that NMJ disassembly after loss of alpha-spectrin can be suppressed by expression of a Wld(S) transgene, providing evidence for a Wallerian-type degenerative mechanism. We then identify a second signaling system.

Reelin depletion in the entorhinal cortex of human amyloid precursor protein transgenic mice and humans with Alzheimer's disease.

Reelin regulates nervous system development and modulates synaptic plasticity in the adult brain. Several findings suggest that alterations in Reelin signaling may contribute to neuronal dysfunction associated with Alzheimer's disease (AD). Cell surface receptors for Reelin, including integrins and very-low-density lipoprotein receptor/apolipoprotein E2 receptor, may be targets of amyloid-beta (Abeta) peptides presumed to play key roles in the pathogenesis of AD.