Remote and selective spatiotemporal control of the activity of neurons to regulate behavior and physiological functions has been a long-sought goal in system neuroscience. Identification and subsequent bioengineering of light-sensitive ion channels (e.g., channelrhodopsins, halorhodopsin and archaerhodopsins) from the bacteria has made it possible to utilize light to artificially modulate neuronal activity, namely optogenetics. Recent advance in genetics has also allowed development of novel pharmacological tools to selectively and remotely control neuronal activity using engineered G-protein coupled receptors which can be activated by otherwise inert drug-like small molecules such as the Designer Receptors Exclusively Activated by Designer Drug (DREADD) - a form of chemogenetics. The cutting-edge optogenetics and pharmacogenetics are powerful tools in neuroscience which allow selective and bidirectional modulation of the activity of defined populations of neurons with unprecedented specificity. These novel toolboxes are enabling significant advances in deciphering how the nervous system works and its influence on various physiological processes in health and disease. Here, we discuss the fundamental elements of optogenetics and chemogenetics approaches and some of the applications that yielded significant advances in various areas of neuroscience and beyond.