Fig. 1.

Increase in synaptic inhibition onto LII/III pyramidal neurons induced by 3,5-dihydroxyphenylglycine (DHPG) is dampened in Fmr1 knockout (KO) mice. A: continuous voltage-clamp traces from a pyramidal neuron under control conditions (i) and in the presence of DHPG (ii), illustrating that DHPG causes an increase in spontaneous inhibitory postsynaptic current (sIPSC) frequency. B: continuous traces from an Fmr1 KO pyramidal neuron, illustrating that sIPSC frequency also increases in response to DHPG in these cells (ii) but that frequency is reduced compared with wild-type (WT) control (i) (see pooled data in E; n = 9 WT and 10 Fmr1 KO neurons). DHPG did not cause an increase in miniature IPSC (mIPSC) frequency in either WT or Fmr1 KO pyramidal neurons (C–E; n = 7 WT and 4 Fmr1 KO neurons). Calibration: 50 pA, 1 s. *P < 0.05.