https://www.reddit.com/r/neuroscience/comments/65pam4/question_how_to_get_into_a_career_in/Math:
Calculus, Linear Algebra, Discrete Math, Differential Equations, Several courses in statistics that get deep into machine learning and dimensionality reduction techniques
Biology:
This is more variable. I would do the minimum amount of biology course work necessary to deeply understand introductory neuroscience courses. Unfortunately, this requires some moderate biochemistry. My recommendation would be to take introductory biology courses and then jump straight into upper division neuroscience.
Neuroscience:
Focus on systems, biophysical, and computational neuroscience courses. Don't waste too much time on molecular, developmental, cognitive, psychological, medicinal, or other subfields of neuroscience. Take graduate level work if you can.
Computer science:
Take the first few mainstream courses, if you can focus on technical computing / mathematical computing. Then take as many machine learning courses as you can. This should be your primary focus.
Electronics:
Take a few basic courses in circuits and electronics
Physics/Engineering:
Take a few engineering courses like statistical mechanics, and signal processing
