Localization of Presynaptic Plasticity Mechanisms Enables Functional Independence of Synaptic and Ectopic Transmission in the Cerebellum

Figure 6

Effect of activation of mGluR1 on Purkinje neuron responses is blocked by antagonism of cannabinoid receptor 1. (a) Representative whole-cell recordings of EPSCs generated by paired pulse stimulation (100 ms interval) of parallel fibres in transverse cerebellar slices at 0.033 Hz before (left hand panels), after 5 minutes incubation with 30 μM DHPG (centre panels), and after 10 minutes of washout (right hand panels). Recordings are shown from cells recorded in the presence of DHPG alone (upper panels) and coapplied with 5 μM SR141716 (lower panels). Cells treated with SR141716 were preincubated with this compound for 5 minutes prior to DHPG addition. (b) Time course of 30 μM DHPG effect on amplitude of the first pulse in each pair, either alone (filled circles) or with 5 μM SR141716 (open triangles), with DHPG incubation at the time indicated by the bar. Data are mean ± s.e.m. from 6 cells for each condition. , one-sample -test. (c) Time course of 30 μM DHPG effect on paired pulse ratio, either alone (open circles) or with 5 μM SR141716 (filled triangles), with DHPG incubation at the time indicated by the bar. Data are mean ± s.e.m. from 6 cells for each condition.

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