Figure 4.

The density and the morphology of dendritic spines in the PrL of adult female mice born from dams exposed to NaAsO₂ during gestation. Dendritic spines were analyzed along the primary basilar dendrites of Golgi-stained pyramidal neurons in three different cortical layers (layer II−III, V, and VI) of PrL. (A) Representative photomicrographs of dendritic spines with maximal intensity projections onto the XY plane from Z-series images (Max-XY) for the control group (Control) and NaAsO₂-exposed group. Photomicrographs analyzed by Spiso-3D (S) and three-dimensional models (Model) are also shown for the analysis of dendritic spines in the layer II−III of the NaAsO₂-exposed group. (B) Effect of NaAsO₂ exposure on the total dendritic spine density of pyramidal neurons in three different cortical layers. Effect of NaAsO₂ exposure on the density of three subtypes of dendritic spines, small-head spines (small), middle-head spines (middle), and large-head spines (large), in three cortical layers of the PrL: Layer II−III (C), Layer V (D), and Layer VI (E). The density of dendritic spines is expressed as the number of spines per 10 μm of dendrite. A total 500−1200 spines from 30 to 45 dendritic segments of 30−45 neurons were analyzed for each cortical layer. Values are expressed as mean ± SEM (control group n = 7, NaAsO₂-exposed group n = 5).