Figure 2
From: Slow GABAAmediated synaptic transmission in rat visual cortex
Quantitative population analysis of spontaneous isolated IPSCs. Trends in the properties of isolated IPSC amplitudes and kinetics (rise and decay time) were determined by comparing these parameters across the entire population of measured isolated IPSCs (n = 954). A) Isolated IPSC decay time constants are shown plotted vs. rise times. Two distinct populations are revealed by a correlation between rise time and decay time constants (Ï„1, first component of the double exponential). Fast IPSCs are shown in gray and slow IPSCs are shown in black. Dashed lines represent the estimated demarcation between populations, based on a slow rise time > 3 ms and decay time > 20 ms. Smoothed density plots are shown to the right. The color-coded density plots indicate that the population is bimodal with separate fast and slow sub-populations that are correlated along rise and decay (Ï„1) times. B) For those events with a significant second exponential component (|A2| > 10 pA, n = 319), Ï„2 (second decay time constant) are shown vs. rise time. Smoothed density profile to the right reveals that these parameters are correlated and cluster into two groups (fast and slow). C-D) Rise time and decay time are shown plotted against event amplitude with smoothed density profile to the right. Neither rise time nor decay time (Ï„1) was correlated with amplitude. The density profiles indicate bimodality along rise time that is uncorrelated with amplitude.