Mapping Cortical Synapses
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To better recognize and analyze synaptic abnormalities in disordered brains, we are using array tomograms like that rendered here to quantify, classify and map synapses in different layers and different regions of cerebral cortex. This movie renders an array tomogram of synapses and cells in layer 5 of mouse whisker-barrel somatosensory cortex. The small red puncta fading in and out through the movie reflect synapsin-1 immunoreactivity, and therefore pinpoint presumptive sites of individual synapses in three dimensions. Putatative synaptic sites can be imaged with high troughput: we counted 191,140 of these synapsin puncta in a volume of 356,400 um3 that was acquired in under one hour. A small subset of neurons (Line H YFP, Feng et al., 2000) is stained green; the blue stained nuclei indicate the presence of unstained cells.