For instance, presynaptic protein, neuronal pentraxin 2 (NPTX2) and neurexin 2a (NRXN2a), and their respective postsynaptic functional partners, GluA4-containing glutamate (AMPA4) receptor and neuroligin 1 were all previously illustrated to be significantly decreased in neuronal exosomes derived from AD patients with cognitive loss [29, 30]. Here, NPTX2 is linked to Alzheimer disease.