Fig. 2

Effects of DE exposure on the olfactory bulb. a and b. Micrograph of an olfactory bulb section from control (a) and exposed (b) GD28 fetuses. The histological coloration reveals the anatomical alterations of the different layers of the olfactory bulbs of exposed GD28 fetuses (b), compared to control ones (a) and the decrease in axonal ends and the presence of areas empty of biological material around glomeruli of exposed fetuses (b and b1) when compared to controls (a and a1). Granule cells clusters seem disrupted on exposed fetuses (b3) when compared to controls (a3). No anatomical differences in the mitral (Mt) cell layer of exposed fetuses (b2) and control (a2) fetuses were observed. Scale bar: 50 μm. c and d. Electron micrograph of the glomerular layer of olfactory bulbs from control (c) and exposed (d) GD28 fetuses. Note a significant decrease in axonal endings and the presence of empty areas (black stars) around the glomerulus from exposed fetuses (d), compared to the glomerulus from control fetuses (c). The PG cells of exposed fetuses exhibit a hypertrophy and a condensation and marginalization of their chromatin (white arrows) compared to PG cells from control fetuses. Scale bar: 20 μm. e and f. Electron micrograph of the granular layer of olfactory bulbs from control and exposed GD28 fetuses. Note the disruption of granular cells clusters, along with a condensation and marginalization of their chromatin, in exposed fetuses (f), compared to the granular clusters from control fetuses (e). Scale bar: 5 μm. nu = nucleus, is = intercellular space