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. 2007 May 30;2(5):e475. doi: 10.1371/journal.pone.0000475

Figure 4. IGF-1 affects intracortical inhibition and perineuronal nets (PNNs) in the developing visual cortex.

Figure 4

(A) Left, representative example of GAD65 immunoreactivity in the rat visual cortex at P25. It is evident the punctate nature of the staining around cell bodies (puncta-ring). To quantify GAD65 immunoreactivity in puncta rings, immunofluorescence in puncta ring was normalized to background signal. Calibration bar 20 µm. Right: light bar: percentage variation of GAD65 puncta ring immunoreactivity between the cortex implanted at P18 with a IGF-1 filled minipump and the cortex implanted with a PBS filled minipump in P25 non-EE animals (N = 7). Percentage variation computed as [(GAD65 immunoreactivity in IGF-1 treated/GAD65 immunoreactivity in PBS treated cortex) –1]×100. GAD65 immunoreactivity is significantly higher in the IGF-1 treated than in the PBS treated cortex (paired t-test, p<0,05, one asterisk). Right, dark bar: Percentage variation of GAD65 puncta ring immunoreactivity between the cortex implanted at P18 with a JB1 filled minipump and the cortex implanted with a PBS filled minipump in P25 EE animals (N = 5). Percentage variation computed as [(GAD65 immunoreactivity in JB1 treated/GAD65 immunoreactivity in PBS treated cortex) –1]×100. GAD65 immunoreactivity is significantly lower in the JB1 treated than in the PBS treated cortex (paired t-test, p<0,05, one asterisk). Vertical bars indicate SEM. (B) Left, representative example of WFA staining (green) and NeuN staining (red) merged image in the rat visual cortex at P25. WFA stained PNN completely surround cortical neurons. Calibration bar 50: µm. Right, leftmost: PNN surrounded cells (WFA positive cells/NeuN positive cells) are more numerous in the visual cortex treated from P18 to P25 with IGF-1 than in the contralateral, PBS treated cortex of non-EE animals (N = 5 animals, paired t-test, p<0,01, two asterisks). Right, rightmost: PNN surrounded cells (WFA positive cells/NeuN positive cells) are less numerous in the visual cortex treated from P18 to P25 with JB1 than in the contralateral, PBS treated cortex of EE animals (N = 6 animals, paired t-test, p<0,05, one asterisks). Vertical bars represent SEM.