Here are the four ways you can keep it strong and healthy.
Always Monitor your eating patterns and make sure to eat semi-regularly so as to not deplete the glucose your neurons use for energy.
Eat a great balanced diet that includes good levels of B-12 and D vitamins, as well as healthy fats.
You really have to Avoid smoking and drinking excessive alcohol, these are what make it unhealthy and more weaker.
Hope this helps!