It sounds like you're trying to make a decision about both careers based on theory and how that matches your personality rather than what either career actually entails. The practical matter of it and how that manifests day to day for 30+ years is something you can't just philosophize. You really need to figure out that info before making a decision by following around real people in different part of their careers in both fields.
My SO is a neurophysio PhD (has had his degree for 5+ years), and I strongly considered a molecular bio research career after working full time in it for a couple years before vet school. For the research track, I can tell you that your career in it is very different than i had imagined it to be when I was in undergrad. Industry is a whole different game (and sometimes it's actually not that easy to suddenly make that leap even though you hear so many people fed up in academia always say, "I'm just going to go into industry one day"). But if you stay in academia, you either be a bench person for much of your career (which apparently you don't like) making pennies as a lowly research non-tenure track professor after a cycle of likely multiple post-docs. That's going to be the most hands on. Or if you are successful in moving up the chain, you start doing more and more paperwork and less and less hands on things. The exciting planning and analyzing and initial putting together of this stuff for publications and kind of gets overshadowed by all the grant writing, rather repetitive sort of recycling of the same info between grants, papers, abstracts, talks, posters, etc... If you thought a life of benchwork was bad, many of these people spend an enormous amount of time in an office with so much paperwork reminiscing the days they got to spend more time on experimental design and data collection/analysis back in their early days. Some people love that career and bust their butts day in and day out to continue making it in this publish or perish trajectory. It can be a great atmosphere overall with passionate colleagues with a sense of camaraderie... or a miserable cut throat one where everyone is out to get ya.
Also Don't just base your decision on what your professor's life appears to be, because the chances that you will 'make it' as a full tenured professor is so slim nowadays. Find ways to talk to post-docs late in their post-docs (esp the ones doing a 2nd or 3rd one), PI's in academic institutions that don't teach, research lifers who don't have their own labs, industry researchers, etc... Or at least a few people who can tell you about all these paths IN neurophysiology if you are sure that is what you want to study.
Same thing for large animal vets. Find people to shadow and talk to that have been in the field for a long time, as well as recent grads both about their lifestyles and work. Also realize that a lot of large animal people end up doing small animal because they either can't find work, or because it becomes too much for their bodies.
