Noise Exposure Alters Glutamatergic and GABAergic Synaptic Connectivity in the Hippocampus and Its Relevance to Tinnitus

Figure 3

VGLUT-1 puncta density primarily increases in dentate gyrus (DG), area CA3, and area CA1 two weeks after noise exposure. Schematic granule cell in DG (a), pyramidal neuron in CA3 (b), and pyramidal neuron in CA1 (c), depicting organization of inputs corresponding to the layers on the right, which are images of VGLUT-1 labeling in CA1 at 400x magnification. Scale bar, 50 μm. Mean (±SEM) normalized VGLUT-1 puncta density (per 10⁴ μm²; normalized to respective control) in the dentate gyrus (DG) (a), area CA3 (b), and area CA1 (c) two weeks following noise exposure are shown on respective right panels. ^#When compared to the controls (dashed line), . ml_d: distal region of molecular layer; ml_m: middle region of molecular layer; ml_p: proximal region of molecular layer; h: hilus; s.o: stratum oriens; s.l: stratum lucidum; s.r: stratum radiatum; s.r_p: proximal region of stratum radiatum; s.r_d: distal region of stratum radiatum; s.lm: stratum lacunosum-moleculare.

(a)

(b)

(c)