How synaptic strength, short-term plasticity, and input synchrony contribute to neuronal spike output
Fig 3
Synaptic transmission between identified L2/3 pyramidal neurons measured with paired whole-cell recordings.
A Example of a synaptically connected pair of L2/3 pyramidal neurons in mouse barrel cortex visualized through post-hoc biocytin histology. B Scatter plot showing, for all synaptic connections, the response to the second pulse versus the response to the first pulse (corresponding to the EPSP amplitude) of the paired-pulse stimulation paradigm. Large dots, average for each connection (n = 22); small dots, six randomly selected single-trial responses for each connection (n = 132). Data points below diagonal indicate depressing synaptic connections, dots above diagonal indicate facilitating connections. C Top, distribution of average EPSP amplitudes recorded between connected L2/3 neurons, the histogram was fit with a lognormal function. Bottom, distribution of average paired-pulse ratios recorded between L2/3 neurons, the histogram was fit with a Gaussian function; R2, goodness of fit. D Left, comparison of average EPSP amplitudes recorded with minimal stimulation (n = 74; same as in Figs 1D and 2A) and with paired recordings (n = 22). Right, comparison of average paired-pulse ratios recorded with minimal stimulation (n = 74; same as in Figs 1E and 2B) and with paired recordings (n = 22). Non-parametric Kolmogorov-Smirnov p-values are indicated. E Scatter plot showing relationship of EPSP amplitude and paired-pulse ratio for synaptic connections between L2/3 pyramidal neurons obtained with paired recordings. Large dots, average for each connection (n = 22; light green, facilitating connections; dark green, depressing connections); small dots, six randomly selected single-trial responses for each connection. The line was fit using linear regression, Pearson correlation results for single-trial data indicated.