Decreased E/I synapse ratio and loss of cortico-LA synaptic plasticity in the absence of coronin 1.

<p>(A, B) Analysis of synapses in brain tissue from wild-type or coronin 1–deficient mice (<i>n</i> = 3) by serial block face scanning by electron microscopy. Scale bar, 2 microns. Data shown are mean values ± SD, <i>p</i><0.01. (C) Hippocampal neurons were labeled using anti-vGLUT1 and anti-vGAT antibodies, followed by Alex Fluor 488 or 568 labeled secondary antibodies, respectively. The average number of inhibitory and excitatory synapses per 10 µm, as well as the E/I synapse ratio from wild-type or coronin 1–deficient neurons were determined. Quantitation (right panel) was done from 60 neuron terminals from four mice per genotype. For vGLUT1, <i>p</i><0.01; for vGAT, <i>p</i>>0.05; and for vGLUT/vGAT ratio, <i>p</i><0.001, Student's <i>t</i> test. (D) Scheme of the experimental preparation (LA, lateral amygdala) and pairing protocols used to induce LTP. (E) Coronin 1–deficient animals (Cor1 −/−, red symbols) exhibited normal thalamo-LA LTP [<i>p</i><0.05 versus baseline; <i>p</i>>0.05 versus wild-type (WT, gray symbols), Student's <i>t</i> test]. Scale bars, 2 mV and 10 ms. (F) Cortico-LA LTP is completely absent in coronin 1–deficient mice (red symbols). Strong cortico-LA LTP was induced in wild-type [WT (grey symbols), <i>n</i> = 12, <i>p</i><0.05 versus baseline, <i>p</i><0.05 versus Cor 1 −/− (red symbols), Student's <i>t</i> test), but not in coronin 1–deficient mice [Cor 1 −/− (red), <i>n</i> = 7, <i>p</i>>0.05 versus baseline, Student's <i>t</i> test]. Scale bars, 50 pA and 20 ms. (G) Synaptic transmission and PPR in wild-type (left) and coronin 1–deficient mice (right) in the presence of forskolin. Forskolin enhances synaptic transmission and decreases PPR at cortico-LA synapses in WT (<i>n</i> = 12, <i>p</i><0.05 versus pre-forskolin baseline), but not in Cor 1 −/− (<i>n</i> = 7, <i>p</i>>0.05 versus pre-forskolin baseline, Student's <i>t</i> test) mice. Scale bars, 100 pA and 20 ms. See <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1001820#pbio.1001820.s018" target="_blank">Table S1</a> for additional statistics.