Fig. 4

Activity-dependent selection between survival and death for new GCs in the OB. A model of how synaptic inputs integrate and determine the fate of new GCs. During olfactory experience, some newly generated GCs (green) receive odor input (red arrows for right GC) while others do not (left GC). Top-down input from the OC to the OB (blue arrow), which typically occurs during the sleep state, eliminates new GCs that did not receive an odor input (left GC) and leave new GCs that did receive an odor input to survive (right GC). OC receives input from other brain regions (gray). Thus, top-down input from the OC might reflect the activity of various brain regions. This figure was modified from [41]