FIG. 4.
There are no changes in MMP-9 mRNA levels or distribution with LTP. A and B: representative film autoradiograms of bilateral hipppocampal sections showing pattern and relative intensity of MMP-9 cRNA probe hybridization. Section in A was taken from an animal 75 min after receiving control stimuli on one side (control stim); section in B was taken from an animal 75 min after LTP was induced tetanically on 1 side (LTP). In both images, the contralateral sides (contra) are also shown for comparison. There are no apparent differences in levels or patterns of probe hybridization across sides or stimulation conditions. Bars, 2 mm. C: quantitative densitometry shows no differences in relative levels of probe hybridization between LTP (n = 6) animals and those receiving control stimuli (n = 4) in s. pyramidale of areas CA1 and CA3, the granule cell layer of the dentate gyrus (DG), or area CA1 st. radiatum (st. rad).