Intracerebroventricular administration of amyloid beta-protein oligomers selectively increases dorsal hippocampal dialysate glutamate levels in the awake rat

Extensive evidence supports an important role for soluble oligomers of the amyloid. beta-protein (A beta) in Alzheimer's Disease pathogenesis. In the present study we combined intracerebroventricular (icv) injections with brain microdialysis technology in the fully conscious rat to assess the effects of icv administered SDS-stable low-n A beta oligomers ( principally dimers and trimers) on excitatory and inhibitory amino acid transmission in the ipsilateral dorsal hippocampus. Microdialysis was employed to assess the effect of icv administration of A beta monomers and A beta oligomers on dialysate glutamate, aspartate and GABA levels in the dorsal hippocampus. Administration of A beta oligomers was associated with a + 183% increase ( p