Figure 6C shows that in the three 9∶1 patches that did have low conductance openings, only a small proportion of bursts, 7.8±1.8% (n = 3), belong to low conductance channels.
Furthermore, there were no effects of altering selection criteria on burst firing analysis: the proportion of bursting neurons increased from 26% in controls to 57% in T GPs, and the burst rate of runs increased from 0.02 ± 0.002 bursts/s in controls to 0.07 ± 0.02 bursts/s in T GPs (P < 0.05).
If bAP recruits only a proportion of receptors, burst firing of the cell should produce larger Ca2+ entry through NMDARs due to the resulting larger dendritic depolarization.
Indeed, in Ortinski et al. (2006), removal of the α1-subunit lead to the disappearance of the relatively small proportion of longer burst seen in +/+ patches, but did not substantially change the characteristics of the predominant brief openings.
Finally, the amount of overlap in activity between alternating (left-right) bursts was measured as the proportion of the total burst time occupied by the simultaneous activity in the paired (left-right) extracellular recordings (Fig. 2C,D, overlap indicated by gray bars).
Neurons with a high percentage of bursts, i.e. the proportion of spikes in bursts were more than 40 50% of the total response (n = 10), did not show significant changes with rTMS@1Hz application (see Figures 3D F).
Neurons with a low percentage of bursts, i.e. the proportion of spikes in bursts was below 40 50% (n = 18), showed a significant increase in the percentage of spikes in bursts when rTMS@1Hz was applied, as it is shown in Figure 3A (21.1±2.2% to 24.0±2.2%, P<0.05, paired t-test) and therefore a decrease in the percentage of tonic spikes (78.9±2.2% to 76.0±2.2%, P<0.05, paired t-test, Figure 3B).
These also did not differ significantly from DYT1 patients (burst index mean 3.64 at rest, and 3.17 with movement, mean proportion of spikes in burst 0.11 at rest and 0.07 with movement).
Bursting properties for the psychogenic patients showed burst indices 4 (2.76 and 6.63 at rest, 2.62 and 1.61 with movement), and proportion of spikes in burst 5 (0.07 and 0.36 at rest, 0.06 and 0.02 with movement).
