Figure 1.
Seizures enhance dendrite outgrowth of newborn granule cells. a, Two weeks after pilocarpine-induced seizures, many EGFP-labeled newborn granule cells had dendrites that extended into the middle and outer molecular layer. b, In control mice, the dendrites of all newborn granule cells terminated in the inner molecular layer. Some newborn granule cells after seizures remained unaffected (a, asterisk). Seizures also appeared to increase the number of labeled newborn cells. Images are maximum intensity z-projections through 50 μm sections from perfusion-fixed POMC-EGFP brains. Image intensity was increased to visualize the layers. Scale bar, 100 μm. gcl, Granule cell layer; iml, inner molecular layer; mml, middle molecular layer; oml, outer molecular layer. c, Seizures increased the total dendritic length and number of branch points of EGFP-labeled newborn granule cells. The cumulative probability distribution of measured values is shown. The x-axis indicates the percentage of values that fall below and above each measurement, such that the median falls at 50%. Twenty-five cells from 15 sections were measured in control mice (n = 10), and 27 cells from 12 sections were measured in mice that had level III–V seizures after pilocarpine injections (n = 3).