The recent development of tools to decipher the intricacies of neural networks has improved our understanding of brain function.Optogenetics allows one to assess the direct outcome of activating a geneticallydistinct population of neurons.Neurons are tagged with light-sensitive channels followed by photo-activation with an appropriate wavelength of light to functionally activate or silence them,resulting in quantifiable changes in the periphery.Capturing and manipulating activated neuron ensembles,is a recently-designed technique to permanently label activated neurons responsible for a physiological function and manipulate them.On the other hand,neurons can be transfected with genetically-encoded Ca2+ indicators to capture the interplay between them that modulates autonomic end-points or somatic behavior.These techniques work with millisecond temporal precision.In addition,neurons can be manipulated chronically to simulate physiological aberrations by transfecting designer G-protein-coupled receptors exclusively activated by designer drugs.In this review,we elaborate on the fundamental concepts and applications of these techniques in research.