Four decades of research on Viktor Mutt’s neuropeptides with focus on galanin

The aim of the article is to describe our work on peptides discovered in Dr. Mutt’s laboratory, particularly galanin. Some personal recollections of meetings with Viktor Mutt and a brief overview of early neuropeptide research at Karolinska Institutet are provided. General aspects on neuropeptide signalling and neuropeptide–neurotransmitter coexistence are followed by the presentation of a possible involvement of the galanin system in pain and depression. Special emphasis is on the role of galanin in the rat and human locus coeruleus. Additional analyses of the human postmortem brains have given results on galanin and other peptides both in the normal prefrontal cortex as well as in different brain regions of depressed patients who have committed suicide and in control subjects. Possible options for developing treatment strategies for pain and depression based on galaninergic mechanisms are discussed. Finally, some recent drugs approved by the FDA for the treatment of conditions such as migraine, which target the signalling of other peptides, are highlighted. In conclusion, the aim of the article is to highlight the potential of the large group of neuropeptides as targets for the development of drugs that may further help patients with illnesses afflicting the nervous system.