text_1: PKG-la plays an essential role in expression of spinal long term potentiation in PGK-la knockout mice.
text_2: Our results thus indicate that presynaptic mechanisms involving an increase in release probability from nociceptors are operational in the expression of synaptic LTP on spinal-PAG projection neurons and that PKG-I localized in presynaptic nociceptor terminals plays an essential role in this process to regulate pain sensitivity.