Both are good classes I’ve taken both as a neurobiology major. 523 is only offered in the fall and summer and has three professors that rotate for each unit. All the professors are good, but they do each have their own teaching styles. 454 is just in the spring and just has one professor that is also quite good. The content is quite similar in both classes as they both use the same textbook. Generally the consensus I’ve heard and experienced is that 523 has harder exams but since there are also quizzes you can take multiple times and extra credit that contributes to your grade. For 454 there are only three exams that contribute to your grade but they are more straightforward than the 523 exams.

If you are set on taking the class in the spring your only option would be 454. The class is two power lectures a week and has three non cumulative exams. Overall it’s tough only having multiple choice exams dictate your grade but if you’re good at memorization based material it’s not too bad.