<Tr> <Td> PP: Neuropeptide B / W </Td> <Td> Neuropeptide B </Td> <Td> NPB </Td> <Td> NPBW1, NPBW2 </Td> <Td>--</Td> </Tr> <Tr> <Td> PP: Neuropeptide B / W </Td> <Td> Neuropeptide S </Td> <Td> NPS </Td> <Td> Neuropeptide S receptors </Td> <Td>--</Td> </Tr> <Tr> <Td> PP: Neuropeptide Y </Td> <Td> Neuropeptide Y </Td> <Td> NY </Td> <Td> Neuropeptide Y receptors </Td> <Td>--</Td> </Tr> <Tr> <Td> PP: Neuropeptide Y </Td> <Td> Pancreatic polypeptide </Td> <Td> PP </Td> <Td>--</Td> <Td>--</Td> </Tr>

Which kind of tissue transmits signals across a synapse