Feng Zhang

The ideal way to study the property of different types of neurons is to control individual types of cells independently and see what happens when you alter one type of cell. Optogenetics helps to realize this goal.

Validation is easy - you run your site through a validator, and it's either valid or it isn't. The rest of the stuff, such as whether my logo or the biggest headline should be the h1 in my HTML, isn't so easy and is subject to interpretation.