Fig 7. Effects of ETS exposure during the early postnatal period on synaptic proteins by immunohistochemistry.

Synapsin I and synaptophysin in the hippocampus in infancy (A-B), adolescence (C-D) and adulthood (E-F). A, C and E—Digital images of coronal sections of the CA3 region stained for synapsin I and synaptophysin. B, D and F—Quantification of synapsin I and synaptophysin levels by averaging the ratio of the optical density in the CA3 region and background in each section. The quantification was performed using three randomly selected fields per section of each animal (n = 5 animals). The data are expressed as the percent of control (means ± SEM). The percent of the control was calculated using arbitrary units. * p <0.05; **p < 0.01 –mice exposed to ETS in the early postnatal period compared to the controls. Arrows: synapsin I or synaptophysin immunoreactivity in the CA3 region of the hippocampus. Scale bar: 100 μm.