Fig. 3.

Activation of group I metabotropic type glutamate receptors (mGluRs) by (S)-3,5-dihydroxyphenylglycine (DHPG), a mGluR1/5 agonist, increases DSI to a greater degree in juveniles than in neonates. A: representative time course of eIPSCs (top) and traces of averaged eIPSCs (bottom) recorded before (left) and during (right) 5-min bath application of DHPG in a PN13 rat. B: same as in A for a PN22 rat. C and D: plot of changes in %DSI of individual cells in Con and in the presence of DHPG for experiments in A and B, respectively (paired t-tests, **P < 0.01; ***P < 0.005). E: histogram shows that DHPG caused a significantly greater increase of DSI magnitude in juveniles than that in neonates (unpaired t-test, **P < 0.01).