Complex sentence: These experiments are now regarded as basic principles of neuroscience research branch of optogenetics which was later improved by Karl Deisseroth in 2005; these pioneering studies in optogenetics led to these three scientists being regarded as candidates for the Nobel Prize in 2013.
Split into simpler sentences: These experiments are now regarded as basic principles of neuroscience research branch of Optogenetics, improved by Karl Deisseroth in 2005. These studies has led to these scientists being regarded as candidates for the Nobel Prize in 2013.