Fig 1.
A comparison of routine cresyl violet (CV) histology and elemental maps (P, S, Cl, K, Ca, Fe, Cu, Zn) revealed by XFI for a representative saline control rat at PND60.
The brain regions of interest are choroid plexus (CP), corpus callosum (CC), striatum (Str), cortex (Ctx), and ventricle wall (VW). All examined elements are observed in the choroid plexus with notably high levels of Fe and Cl relative to other brain regions. Scale bar = 500 μm, intensity units are μg cm-2.
Fig 2.
An enlarged view of elemental maps of Cl−, K+ and Cu in the choroid plexus and ventricle wall with tri-colour overlay.
Numerous Cu hot spots mark the ventricle wall, and Cl− and K+ co-localize with the choroid plexus epithelium. The tri-colour overlay highlights that K+ is at lower concentration outside the choroid plexus epithelium, while Cl− is still abundant. Scale bar = 100 μm.
Fig 3.
Elemental quantification performed with XFI of distinct brain regions (choroid plexus, corpus callosum, striatum, cortex, and ventricle wall).
One-way repeated measures ANOVA revealed significant differences in all elements as a factor of brain region (p<0.05). Tukey’s HSD was used to calculate post hoc tests. [A] Elemental concentrations for P, S, Cl, and K. A letter system is used to denote significant differences in P across brain regions. A = significantly different from choroid plexus, B = significantly different from corpus callosum, C = significantly different from striatum, D = significantly different from cortex, E = significantly different from ventricle wall. For all other elements, significant differences are indicated with an asterisk (*). [B] Elemental concentrations for Ca, Fe, Cu, and Zn. Significant differences are indicated with an asterisk (*).
Fig 4.
[A] Radial profiles of Cl−, K+, and Ca2+ concentrations across the ventricle wall, sub-ventricular zone, and surrounding striatum. [B–D] XFI elemental maps of Cl−, K+, and Ca2+, respectively, illustrating the region from where radial profiles were calculated (white dashed box). Scale bar = 100 μm, intensity units are μg cm-2.
Fig 5.
Routine cresyl violet (CV) histology and XFI elemental mapping (P, S, Cl, K, Ca, Fe, Cu, Zn) of the offspring (PND60) from a saline control rat and a polyI:C immune compromised rat.
Images were collected from tissue sections -0.5 mm and -3.6 mm anterior to bregma. White arrows indicate the presence of numerous calcifications observed within the ventricles of the polyI;C offspring. Due to the increased swelling of the ventricle in the polyI:C offspring at bregma location -0.5mm, the medial side of the ventricle wall tore from the tissue section. A white dashed line shows the approximate location of the ventricle wall before it tore away during tissue sectioning. Scale bar = 500 μm, intensity units are μg cm-2.
Fig 6.
Replication of the Cl− results from elemental mapping at the Australian Synchrotron was performed at the Stanford Synchrotron Radiation Lightsource using tissue sections from a similar anatomic plane collected from the opposite brain hemisphere to those presented in Fig 5.
Elemental maps of Zn distribution are shown to highlight tissue anatomical structure (grey matter contains high Zn, white matter contains low Zn). Scale bar = 100 μm. Elemental maps are displayed on a relative scale, the scale is the consistent for all Zn maps, and a separate but consistent scale is used for all Cl− maps.
Fig 7.
Cresyl violet (CV) histology and XFI elemental mapping of calcifications (white arrows) within ventricles.
The first two columns correspond to images collected from tissue sections at a location of -0.5 mm anterior to bregma, and the last two columns correspond to images collected from tissue sections at a location of -3.6 mm anterior to bregma. Scale bar = 100 μm, intensity units are μg cm-2.