Its properties are similar to those of bacteriorhodopsin, and these two light-driven ion pumps transport cations and anions in opposite directions.

Halorhodopsin isoforms can be found in multiple species of halobacteria, including Halobacterium salinarum, and Natronobacterium pharaonis.

[2][3] Halorhodopsin from Natronomonas (NpHR) has been used to achieve inhibition of action potentials in neurons in mammalian systems.

[7] The name Halorhodopsin is of Greek origin, the halo- prefix emerging from ἅλς (háls) meaning "salt" or "sea".

[8] The suffix -rhodopsin originates from ῥόδον (rhódon, “rose”), due to its pinkish color, and ὄψις (ópsis, “sight”).

Optogenetics has been proposed as therapeutic approach to neurological conditions for which current treatment methods are not always effective, including epilepsy and Parkinson's disease.