Sniff-Like Patterned Input Results in Long-Term Plasticity at the Rat Olfactory Bulb Mitral and Tufted Cell to Granule Cell Synapse

Figure 1

TBS induces LTD at the MTC-GC synapse. (a) Experimental design [25]. Glomerular stimulation (Stim) will activate the glomerular ensemble of mitral cells to a varying extent (depending on stimulation strength); thus inputs from several mitral cells onto the recorded GC (Rec) will be activated. (b) Response of individual granule cell to single glomerular stimulation (two individual responses shown, note the barrage of activity in the second response). (c) Coefficients of variation of EPSP amplitude of synaptic connections versus their mean EPSP amplitude for control data (black dots) and long-term data (grey circles). For control, the fit has a slope of − (mean ± SD) on the log scale (black line) and for long-term the slope was −. The confidence intervals were calculated from bootstrap replicas of the data. The arrows mark the data points from the connection shown in (e). (d) Response of the cell from (b) to TBS (average of the total of 10 stimulations). (e) EPSP amplitudes from individual GC recordings from the cell in (b) and (d) over time. Control mean 8.1 mV; long-term mean 6.3 mV (dashed lines). (f) Cumulative data (normalized to control) of all experiments with substantial LTD (black diamonds, ) and of all experiments in the presence of 25 μM APV (grey squares, ). Respective long-term averages shown as dashed lines (grey for TBS and black for TBS in APV). All data points ± SD across experiments. (g) Representative individual experiment in the presence of 25 μM APV. Control mean 2.9 mV; long-term mean 2.7 mV (dashed black lines). degree of the statistical difference between the last data point before TBS and the first data point after TBS (black diamonds).