Predoctoral fellowships for MS graduate, pre-PhD

[dvwz]

Hope there are people with advice for a unique situation. I have a MS and planning to apply for PhD. I'd like to apply for fellowships concurrently or before, in order to make my PhD application more competitive by bringing funding myself to whatever institution where I'd like to study. I'm having difficulty finding predoctoral fellowships for folks who are not already in a PhD program and not a college senior. I'm currently a research assistant in a lab (neuroscience) and I have a MS. Any ideas would be appreciated, thanks.