ADORA2A and Parkinson disease: Importantly, this A2AR overactivation driven by an increased ATP release contributes to an increased LTP magnitude during the presymptomatic phase of PD (58.78 ± 2.53% over baseline) compared to control conditions (50.84 ± 1.38% over baseline; t19 = 2.82, p = 0.011), when considering the pooled data from the two experimental groups displayed in Fig. 6H and I (Fig. 6J).