nervous system
• homozygotes display a ~20% reduction in total zinc levels in the hippocampus and cortex relative to wild-type mice
• Timm stain (a stain for histochemically reactive zinc) is undetectable in the hippocampus, neocortex, piriform cortex, amygdala, entorhinal cortex, striatum, olfactory bulb, and cochlear nucleus of homozygous mutant mice
• in the hippocampus, Timm staining is undetectable in the mossy fibers projecting from dentate granule neurons to the hilus and s lucidum and s oriens of the CA3 region, and in projections to s radiatum and s oriens of the CA1 region
• no Timm-staining is observed within synaptic vesicles of homozygous mutant mossy fiber boutons
• in contrast, Timm staining is readily detectable in the choroid plexus and in convoluted tubule cells of the submaxillary gland, while TSQ fluorescence is still abundant in differentiating spermatids and in beta-islet cells of the pancreas
• TSQ fluorescence (a specific indicator of vesicular zinc) is undetectable in the hilus and CA3 and CA1 regions of mutant hippocampus
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• mutant hippocampi display normal mossy fiber bouton ultrastructure, with densely packed clear, round synaptic vesicles, a few dense core vesicles, and numerous mitochondria, but lack histochemically reactive zinc within the synaptic vesicles
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• no Timm-staining is observed within synaptic vesicles of homozygous mutant mossy fiber boutons, indicating that histochemically reactive zinc is eliminated from synaptic vesicles
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homeostasis/metabolism
• homozygotes exhibit impaired zinc transport into synaptic vesicles
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• homozygotes display a ~20% reduction in total zinc levels in the hippocampus and cortex relative to wild-type mice
• Timm stain (a stain for histochemically reactive zinc) is undetectable in the hippocampus, neocortex, piriform cortex, amygdala, entorhinal cortex, striatum, olfactory bulb, and cochlear nucleus of homozygous mutant mice
• in the hippocampus, Timm staining is undetectable in the mossy fibers projecting from dentate granule neurons to the hilus and s lucidum and s oriens of the CA3 region, and in projections to s radiatum and s oriens of the CA1 region
• no Timm-staining is observed within synaptic vesicles of homozygous mutant mossy fiber boutons
• in contrast, Timm staining is readily detectable in the choroid plexus and in convoluted tubule cells of the submaxillary gland, while TSQ fluorescence is still abundant in differentiating spermatids and in beta-islet cells of the pancreas
• TSQ fluorescence (a specific indicator of vesicular zinc) is undetectable in the hilus and CA3 and CA1 regions of mutant hippocampus
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