Fig. 4

Purinoceptors mediates neurotransmission in nervus system. In presynaptic terminal, ATP is enriched in vesicles by transporter VNUT and then released in a Ca²⁺-dependent manner, or exported by other channels such as Panx1 independent of Ca²⁺. On one hand, extracellular ATP and its degradation product adenosine in turn activate purinoceptors in presynaptic terminal. This effect may regulate the release of other transmitters such as glutamate. On the other hand, extracellular ATP and adenosine can interact with postsynaptic purinoceptors, thereby regulating the excitability of neural cells. This event might also lead to the internalisation of AMPAR and NMDAR on postsynaptic membrane, leading to a decrease of glutamate-induced current. VNUT vesicular nucleotide transporter, Panx1 pannexin 1, AD adenosine, AMPAR AMPA receptor, NMDAR N-methyl-d-aspartate receptor