Figure 6.
VGLUT1-ir is decreased, whereas VGLUT2 is increased in the CN ipsilateral to the cochlear damage. Photomicrographs of VGLUT1-ir from the VCNm of one animal contralateral (A) and ipsilateral (B) to the cochlear damage, 2 weeks after kanamycin injections into the left cochlea. VGLUT1 is strongly expressed in PVCNm on the control side (B) as previously shown (Zhou et al., 2007) but weakly expressed ipsilateral to the deafening (A). The decrease in VGLUT1-ir reflects primarily decreased VIIIth nerve synaptic inputs after kanamycin injections into the cochlea. C,D, Photomicrographs of VGLUT2-ir from SHELL regions of CN. VGLUT2-ir in the ipsilateral SHELL region is increased ipsilateral (C) to the cochlear damage compared with the contralateral side (D). Scale bars: A–B, 50 μm; C,D20 μm. E. shows ratio plots (after deafening/before deafening) for VGLUT1 and VGLUT2 across CN regions. From Zeng et al., 2009.