Figure 7.

Post-tetanic depression is regulated by A1 adenosine receptors. A, Post-tetanic depression induced by multiple photolysis of NP-EGTA in glial cells was blocked by the A₁ receptor antagonist PSB-36. B, No post-tetanic depression was elicited by multiple photolysis at NMJs of A₁ −/− animals. C, Post-tetanic depression was occluded by prior addition of the A₁ agonist CCPA. D, Presence of the A_2A receptor antagonist SCH has no effect on post-tetanic depression. E, Post-tetanic depression was evoked by the multiple photolysis protocol at NMJs from A_2A −/− mice. Insets in the graphs illustrate typical PSC Ca²⁺ responses elicited by photo-activation of NP-EGTA. Insets on the right show representative PSPs (averages of 30 events) taken from a single recording at the 15 min time point. pre, Before; post, after.