Skip to main content
. 2002 May 15;541(Pt 1):123–137. doi: 10.1113/jphysiol.2001.016063

Figure 2. Co-release of GABA and glycine.

Figure 2

A, miniature IPSCs were recorded in the presence of TTX, kynurenate, and flunitrazepam to prolong GABAAR-activated currents. Three types of mIPSCs were observed: fast decaying mIPSCs (*) slow decaying mIPSCs (○) and compound mIPSCs (dual component, arrow). B, fitting procedure for mono- and bi-exponential decays of mIPSCs. Upper and middle traces, mono-exponential fits (dashed lines) with corresponding parameters given beneath the traces. The second term of the equation was equal to 0. Lower trace, bi-exponential fit. C, pharmacological characterization. In the presence of bicuculline (10 μM), only fast mIPSCs were observed. In the presence of strychnine (1 μM), only slow mIPSCs were recorded. D, histograms of decay time constants of compound mIPSCs in control conditions (upper) and under selective GABAAR and glyR antagonists (bottom) in a single aMn. The decay time constant of the faster component of compound mIPSCs (τ1, 14 events) corresponds to that of glyR-mediated mIPSCs (47 events) and the decay time constant of the slower component (τ2, 14 events) corresponds to that of pharmacologically isolated GABAAR-mediated mIPSCs (87 events). E, amplitude histogram of glyR- (612 events, 4 cells) and GABAAR-mediated mIPSCs (225 events, 4 cells). F, estimation of the proportion of GABAAR- and glyR-activated mIPSCs in control conditions. Upper graph, distribution of the decay time constants of mIPSCs in the presence of 10 μM bicuculline (464 events, 3 aMns). 92 % of the events had a decay time constant < 15 ms (vertical arrow). Middle histogram, distribution of the decay time constants of mIPSCs in the presence of 1 μM strychnine (120 events, 3 aMns). 92 % of the events had a decay time constant > 15 ms (vertical arrow). Lower histogram, distribution of decay time constants of single exponential mIPSCs in control conditions (324 events, 3 aMns). Events on the right of the vertical arrow (42 %) are considered to be GABAergic mIPSCs, and those on the left glycinergic mIPSCs (58 %).