Table 3.

Spatial relationship between Ca_V2.1 or GIRK2 and GABA_B1 clusters

Clusters	Compartment	Inter-cluster distance	N
GIRK2 to GABAB1	Active zone	84.2 ± 46.1	21
	Dendrite	219.6 ± 119.0	54
	Spine	110.7 ± 73.4	100
CaV2.1 to GABAB1	Active zone	68.5 ± 45.1	44
	Dendrite	124.2 ± 126.7	85
	Spine	154.9 ± 85.9	31

Inter-cluster distances from Ca_V2.1 or GIRK2 clusters to the nearest neighbouring GABA_B1 clusters are reported as mean ± standard deviation. Inter-cluster distances between GIRK2 and GABA_B1 in dendritic shafts differed significantly from both the ones in spines (p < 0.001) and in active zones (p < 0.001), while there was no significant difference between inter-cluster distances in spines and active zones (p = 0.12). Inter-cluster distances between Ca_V2.1 and GABA_B1 were showed significant differences between active zones and dendritic shafts (p = 0.004), active zones and dendritic spines (p < 0.001) as well as dendritic shafts and spines (p = 0.009). p values were obtained by Mann–Whitney U test followed by Holm–Bonferroni correction. N indicates the number of Ca_V2.1 or GIRK clusters analysed