Sudden Intrabulbar Amyloid Increase Simultaneously Disrupts Olfactory Bulb Oscillations and Odor Detection

Figure 1

Location of the electrodes and injectors, experimental design, recordings, and composition of the Aβ_1-42 oligomeric solution. (a) Left: scheme of the OBs and location of a guide cannula in each surface (at the limits between the glomerular and external plexiform layers). The injectors reaching the granular cell layer (GCL) are also represented. One cannula with its corresponding injector is expanded to exemplify that the tip of the cannula is exposed and conductive (in black) for use as a recording electrode. Right: coronal sections of both OBs showing the tracks left by both cannulae and the injectors. (b) Temporal organization (horizontal line) of the local field potential (LFP) recordings of both the left and right (L/R) OBs and the application of two buried food tests: the first (1) just before Aβ administration and the second (2) performed 60 min after Aβ administration. Note that LFP recordings were uninterrupted during the entire experiment. (c) Representative traces of the activity of both OBs 60 min after the administration of either Aβ_1-42 (upper traces) or its reverse sequence Aβ_42-1 (lower traces). (d) Silver-stained gel of the electrophoretic pattern of the Aβ_1-42 oligomerized solution (right lane; monomers, dimers, trimers/tetramers, and heptamers/octamers are the main oligomeric forms) along with a molecular-weight (MW) size marker (left lane).

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