Table 2.

Distribution of BrdU + cells in the SVZ, RMS, and OB of the naris-occluded and naris-reopened hemispheres

Time after BrdU injection and naris reopening	OB			RMS	SVZ
	GL	EPL	GCL
1 h
Control	130 ± 19	94 ± 8	366 ± 30	1844 ± 45	6920 ± 355
Occlusion	96 ± 12	64 ± 13	322 ± 11	1838 ± 191	6830 ± 237
1 week
Occlusion	644 ± 132	228 ± 28	5624 ± 567	7226 ± 187	2174 ± 132
Reopening	586 ± 88	212 ± 7	7228 ± 575	7870 ± 375	2230 ± 245
4 weeks
Occlusion	624 ± 76	120 ± 30	5558 ± 400	50 ± 12	77 ± 17
Reopening	931 ± 53*	89 ± 8	7376 ± 473 *	45 ± 10	84 ± 11

After 4 week naris occlusion, mice were injected with BrdU and the nasal plug was removed. Number of BrdU+ cells in the SVZ, RMS, and three OB layers (GL, EPL, and GCL) was counted 1 h, 1 week, and 4 weeks after BrdU injection. There was no significant difference in the number of BrdU+ proliferating cells in each region between the naris-occluded and control hemispheres (1 h). One week after BrdU injection, neuronal progenitors in the SVZ and RMS that had incorporated BrdU migrated toward the OB, resulting in a wide distribution of BrdU + cells along the SVZ–OB pathway. Naris reopening did not affect the distribution of BrdU + cells in the SVZ–OB (1 week). Four weeks after BrdU injection, we quantified the surviving BrdU+ cells in the GCL and GL layers of the OB. Naris reopening increased the number of BrdU+ cells in these layers (4 weeks, n = 4 animals in each condition;

*p < 0.05, unpaired t test).