The expression of a7 GFP appears to intensify after P10, and by P12 signal is consolidated almost exclusively in the ventral-posterior cochlear nucleus (Fig. 7B ). This is in agreement with reports from in situ hybridization studies reporting the strong expression of a7 in this nucleus, whereas other major cochlear nuclear divisions exhibited only weak or sporadic labeling (Yao and Godfrey 1999; Morley and Happe 2000) . Also consistent with those studies was that the cells identified by a7 GFP expression resemble octopus cells (Fig. 7B, insert) . Essentially, no expression of a7 GFP was detected in the dorsal cochlear nucleus, although some dispersed and weakly stained cells were present in the granular aspect. Also evident was the strong staining of neuropil, presumably in part due to terminals of SG cells associated with the eighth cranial nerve (Fig. 7B, inset) . This strong labeling of the P12 SG and OHC afferents is consistent with other reports (Morley and Happe 2000) .