Professor Job Prospects for PhD in Computer Science vs Computational Neuroscience? If one wants to do research in computational neuroscience, which PhD program would increase the chances of getting a professor job at a research university immediately upon graduation from that PhD program the most? Assuming, all else being equal.

A) PhD in Computer Science

B) PhD in Computational Neuroscience  

In other words, for which of the two PhD degrees is there more demand and less supply in academic job markets, if research interests are in neuroscience?
I will share my own results from my research as I am on the same boat (Torn between Bioinformatics/CS). From looking at profiles of recently appointed faculty across institutions, it certainly seems easier to get a position if you are a CS graduate.
Due to higher volumes of CS PhD's, most end up going in industry or doing post-docs for 1-2 yrs before getting a faculty position. Whereas grads from other disciplines (Computational neuroscience/bioinformatics) usually end up doing post-docs for a bit longer and I have rarely seen a recent faculty appointment in these areas without a post-doc. 
All reasons aside, It will greatly depend on your research/publications and to some degree the institution and your supervisor.