Fig. 8.
Sensitivity of AIS and DCN terminals to purinergic agonists. (A, Upper) In the PC layer, staining for the purinergic receptor P2Y1R (green) coincides with that for ankyrin G in AIS regions of PCs (red). (A, Lower) P2Y1R staining in terminals surrounding DCN principal neurons. (B) In GCaMP6f-expressing PCs in acute slices, local pressure application of the specific P2Y1R agonist MRS 2365 (100 μM in puffer pipette) in the AIS elicits a Cai response both in the AIS (black) and in a presumptive presynaptic terminal (yellow). (C) Recordings from DCN somata in dissociated cultures. (C, Upper) ATP uncaging (pink bar above current trace) elicits prolonged increase in miniature IPSC frequency. (C, Lower) Summary data (n = 6) showing that ATP uncaging increases mIPSC frequency (t and P values of −4.2 and 0.008) but does not change mIPSC mean amplitude. Gray triangles correspond to average values from five experiments using the same laser protocol at twice the power, but with no cage present in the extracellular solution. There was no effect on either frequency or amplitude.