The peptide or the neuron?

摘要

Imagine this. You have identified and sequenced a novel neuropeptide. You find that it is expressed selectively in such brain regions as suggest that it plays a role in an important function such as eating, sex or memory. You synthesize the peptide and inject it into the brain, where its actions support your hypothesis. What do you do next? Knock out the gene! After all the difficulties and setbacks associated with that process, you finally convince yourself that you have indeed produced a mouse that no longer expresses the peptide in question. You then examine the animal. If it has a phenotype that supports your hypothesis, all well and good. If it has a different, unexpected peculiarity, that just might be even more interesting. But what if it appears identical to its wild-type littermates- anyway as far as you can discern with your methods? If one has the mindset that seeks to explain brain function neuro-chemically, this may result in much hand waving and special pleading (followed by publication with a lot of bolstering data in a less prestigious journal than originally planned). But should it?