Figure 1

Cell turnover in the naked mole rat.

(a–c) Analysis of EdU⁺ cells in the hippocampus and svz-rms-ob axis of the adult mouse, pulsed for seven consecutive days with EdU. A sagittal overview showing the two main adult progenitor zones, the hippocampus (grey; 1) and rostral migratory stream (purple; 2,3) in the mouse and naked mole rat brain is depicted in (a). EdU⁺ cells are shown in red (arrowheads). Doublecortin⁺/EdU^- cells (open arrowheads) decorated the subgranular zone. (d–f) In the 10-year-old naked mole rat, substantially less EdU incorporation is found in the dentate gyrus and svz-rms-ob axis. Note the lack of DCX in the subgranular zone. (g–i) EdU⁺ cells were found in increasing quantities in the svz<rms<ob axis 8 weeks post EdU exposure in the naked mole rat. Remarkably, only a few EdU⁺ cells remained as compared to the cohort labeled in (d–f). (j) Doublecortin⁺ corridor intermingled with EdU⁺ cells in the RMS of the 4-year-old naked mole rat. (k–l) Apoptotic cells (cleaved caspase-3⁺; green circles in (g)) were found scattered throughout the 21-year-old naked mole rat brain, including the arcuate nucleus (arrowheads) (k), dorsal striatum (CPu) and somatosensory cortex (l). Fragmented nuclei (asterisk) confirm nuclear condensation. Abbreviations: arc, arcuate nucleus; CPu, caudate putamen; ctx, cortex; hc, hippocampus; n, nucleus; ob, olfactory bulb; rms, rostral migratory stream; sgz, subgranular zone; svz, subventricular zone. Scale bars = 75 μm (c,f,I,j), 20 μm (k), 10 μm (l).