Fig. 5.

Pyramidal neurons are increasingly damaged and swollen closer to the cut surface of a live brain slice as imaged with 2-PLSM. Optical sections through the CA1 dendritic region. The mouse expresses eGFP in random pyramidal neurons. a Sections are captured at depths progressively closer to the slice’s cut surface. Closer to the cut surface (10 µm), there is increased dendritic swelling/beading as more branches of each CA1 arbor are cut. Images adapted from Davies et al. [47]. b Two-photon fluorescence images of neurons in the hippocampal slice scanned at successively deeper levels. Grossly beaded and swollen CA1 pyramidal neurons are imaged near the sliced surface. Neurons take on a normotypic structure with depth. Images from Dzhala et al. [48]. c Pyramidal cell bodies resist volume increases induced by osmotic stress but swell following SD. Masks representing the control volumes of two cell bodies somata in (C1) are placed over the same somata following subsequent treatments. Exposure to hypoosmotic aCSF (– 40 mOsm) reveals no increase in somata volume at 5–6 min (C2) or 15 min (not shown). Following return to control aCSF (C3), exposure to aCSF with 26 mM K⁺ for 2–3 min evokes cell body swelling (C4, arrows), which is reversible (C5). 20 min post OGD (C6), swelling is even more pronounced (arrows) and proximal dendrites fade. 2-PLSM, two-photon laser scanning microscopy, aCSF, artificial cerebrospinal fluid, eGFP, enhanced green fluorescent protein, mM, millimolar, mOsm, milliosmole, OGD, oxygen–glucose deprivation, SD, spreading depolarization, SR, stratum radiatum, SP, stratum pyramidale, SO, stratum oriens, µm, micrometer.