mGluR1 regulates ethanol sensitivity of VTA neurons from mice during diestrus. A, Rate meter graph represents the response of an individual neuron to 40-120 mm ethanol before and after treatment with the mGluR1 antagonist JNJ 16259685 from a mouse in estrus. B, Ethanol concentration-response graph of neurons (n = 5) from mice in estrus before and after treatment of slices with JNJ 16259685. C, Rate meter graph represents the response of an individual neuron to 40-120 mm ethanol before and after treatment with JNJ 16259685 from a mouse in diestrus. D, Ethanol concentration-response graph of neurons (n = 6) from mice in diestrus before and after treatment of slices with JNJ 16259685. The ethanol excitation of neurons from mice in diestrus was significantly reduced after treatment. *p < 0.05, main effect of treatment (two-way repeated-measures ANOVA).