Most of this work is grant-funded, so the publication fees usually also come out of the grants. Primary investigators are not usually paying this out of pocket.

Most of this work is grant-funded, so the publication fees usually also come out of the grants. Primary investigators are not usually paying this out of pocket. It's entirely so that you can have an item in your publication list or CV that says "Nature Neuroscience" on it, in your fight for a tenure-track promotion, or to get the next grant, or to get a grant renewed, etc. Especially in life sciences, peer review is an essential component, and name recognition of the journal is unfortunately valuable- for Nature/Cell/Science due to the high bar they have for novelty, compared to other respectable but not-top-tier journals like PLoS.