Skip to main content
. Author manuscript; available in PMC: 2014 Oct 3.
Published in final edited form as: Nature. 2014 Mar 26;508(7494):55–60. doi: 10.1038/nature13165

Figure 1. Signalling pathways controlling capillary diameter.

Figure 1

a Capillaries in the molecular layer of rat cerebellum labelled using isolectin B4; pericytes (arrow) labelled with NG2 or PDGFRβ antibodies. b Cerebellar capillaries in NG2-DsRed mouse; pericytes are red. c Neocortical capillaries in NG2-DsRed mouse; microglia labelled for Iba1. d Rat cerebellar capillary response to 2μM noradrenaline (NA) and superimposed 500μM glutamate (Glut). Line shows lumen diameter. e NA-evoked prolonged constriction (95% O2; a large constriction is shown for clarity). f Diameter in NA was not affected by [O2] (graphs show percentage of baseline diameter before drugs). g Glut dilates capillaries (20% O2; a large dilation is shown for clarity). h Dilation was larger in low [O2]. i NOS blocker L-NG-nitroarginine (L-NNA, 100μM) inhibits Glut-evoked dilation (20% O2). j Guanylyl cyclase blocker ODQ (10μM) does not block dilation (20% O2). k Blocking 20-HETE production (HET0016, 1μM) abolishes the inhibitory effect of L-NNA (20% O2). l L-NNA reduces Glut-evoked dilations at high and low [O2] (ANOVA p=0.002; p values from post-hoc t-tests). m ODQ does not affect Glut-evoked dilation. n HET0016 abolishes effect of L-NNA. o, p Blocking EP4 receptors (L161,982, 1μM) inhibits Glut-evoked dilation (o, 20% O2) at high and low [O2] (p). Data in d-p are from rat cerebellar capillaries. q EP4 block abolishes Glut-evoked dilation in rat neocortical capillaries (20% O2). Drug effects on baseline diameter are in Ext. Data Fig. 2.