terminals also contain octopamine (the invertebrate equivalent of norepinephrine ) and neuropeptides . The larval NMJ expresses postsynaptic receptors that are homologous to the vertebrate AMPA and kainate receptors. Larval NMJ Morphology: Axon branches terminate on surface of muscles to form synaptic endings (collectively called the NMJ). NMJs stained with peroxidase-conjugated