ADORA2A and Parkinson disease: Second, this A2AR overfunction in the presymptomatic phase of PD is not expected to be the sole or main determinant defining the magnitude of LTP; in fact, LTP magnitude is dependent on a large variety of executors and A2AR are only modulators fine-tuning different key elements responsible for the implementation of synaptic changes, such as, for instance NMDA receptors (e.g., [26]).