This is how it looks finished.
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There is a template for JNeurosci on Authorea:
You have to log in to Authorea to access it I think, but having done that, you have the option of downloading a
.tex file, via a button in the top right:
Note: The output does not look like a published article, but neither should it. Most journals use one format for submission, and a different one for publishing. You are not supposed to worry about getting the format just like what you show in your image, only that you follow the author instructions on the journal website. That means for example using the structure described there, and that your document has double line spacing and numbered lines.