Neuropeptide C0027895 C686 Neuropeptide A member of a class of protein-like molecules made in the brain. Neuropeptides consist of short chains of amino acids, with some functioning as neurotransmitters and some functioning as hormones. Neuropeptide Amino Acid, Peptide, or Protein Neuropeptide neuropeptide Peptides with direct synaptic effects or indirect modulatory effects on the nervous system. A neuropeptide is a molecule released by neurons as an intercellular neurotransmitter. Alternatively, neuropeptides can be released by non-neuronal cells as hormones. They are endogenous peptides such as endorphins that influence neural activity or functioning. protein