FIGURE 5.

Running modifies the connectivity of 1-wk-old and 1-mo-old new neurons

Running shifts the contributions of presynaptic cell populations (percentage of total traced cells) to the wiring of new dentate granule cells (GC) at 7 days (d) and 30 d of age. At 7 d, running reduces the input and connectivity from area CA1 pyramidal cells, whereas hilar cells (interneurons and mossy cells) show a trend toward an increased contribution. At the 30-d time-point, running results in recruitment of afferents from entorhinal cortex [perirhinal (PRH) and lateral entorhinal cortex (LEC), caudo-medial and medial entorhinal cortex (CEnt/MEC)], whereas hilar input (interneurons and mossy cells) is reduced. The largest fold change in connectivity was observed in the medial mammillary (MM) and supramammillary (SUM) neurons. The photomicrographs depict traced SUM cells expressing MCherry (red) in horizontal sections derived from control and running mice. Nuclei were stained with DAPI (blue). Figure was modified and reproduced from Ref. 139, with permission from Neuroimage.