Figure 2.
Aβ ELISA and in vivo microdialysis technique. A, Aβ species detected by ELISA for human Aβ1-x, Aβ40, and Aβ42. Top, Aβ peptide sequence with epitopes recognized by each monoclonal (m) antibody. Bottom, Aβ species detected by each ELISA assay; solid lines represent segments of peptide that must be present for detection, and dashed lines represent segments of peptide that may vary but will still be recognized by the various antibody combinations. B, Awake mouse implanted with dual microdialysis probes. Black arrow denotes guide cannula-probe assembly; white arrow denotes collar used to attach mouse to balance arm that prevents force from being applied to implanted assembly. C, D, Representative probe placements in the hippocampus and striatum, respectively. Note partial probe tracts within each section. Hashed line depicts probe location. D, Cresyl violet stain of tissue surrounding the microdialysis probe tract after 18 hr implantation. There is no morphological evidence of substantial gliosis or inflammation along the tract (arrows), nor is there evidence of neuronal degeneration within the dentate granule cells. F, In vivo percentage recovery at various flow rates as determined by the interpolated zero flow method. At 0.5 and 2.6 μl/min, the percentage recovery of eAβ is 56.3 ± 4.21 and 4.9 ± 0.90% (n = 4), respectively.