Fig. 3.
Distribution of immunogold particles indicating A1R (A) or P2Y1R (B) in different intra- and extracellular compartments. Note that both receptors are enriched at synapses and astroglia, compared to all other compartments. Data, from single labelling experiments, report the localization of receptors as the density (gold particles/µm2; mean ± SEM) in the different compartments in the vicinity of hippocampal glutamatergic synapses (i.e. asymmetric synapses on spines, see Materials and methods; randomly selected, from n = 3 animals; five grids analysed for A1R and six grids for P2Y1R); the areas of the compartments were measured by point analysis (see Materials and methods). The numbers of gold particles on each structure are, in order 323, 230, 1, 52, 24, 31, 15 for A1R; 330, 311, 5, 112, 35, 31, 32 for P2Y1R. Areas analysed for each compartment are, in order 10.8, 7.7, 0.1, 1.1, 0.2, 0.6, 1.3, 1.0 µm2 for A1R, 12.1, 8.8, 0.2, 2.1, 0.2, 0.9, 1.7, 0.8 µm2 for P2Y1R. (A) A1R. **P < 0.01, one-way anova, all compartments compared to mitochondria (Dunnett's multiple comparison test). Synaptic cleft is significantly different compared to all other domains (#P < 0.01, one-way anova, Tukey's multiple comparison test). Astrocytes and synaptic cleft columns showed higher receptor density (§P < 0.05, Student's t-test, two-tails, unpaired) compared to mitochondria. (B) P2Y1R; *P < 0.05, **P < 0.01 all domains compared to mitochondria, one-way anova (Dunnett's multiple comparison test). Synaptic cleft is significantly different compared to all other domains (#P < 0.001 vs. all except astrocytes, P < 0.01 vs. astrocytes, One-way anova, Tukey's multiple comparison test).