Step-function luminopsins for bimodal prolonged neuromodulation

Ken Berglund, Alejandra M. Fernandez, Claire Anne N. Gutekunst, Ute Hochgeschwender, Robert E. Gross

Research output: Contribution to journalArticlepeer-review

18 Scopus citations


Although molecular tools for controlling neuronal activity by light have vastly expanded, there are still unmet needs which require development and refinement. For example, light delivery into the brain is still a major practical challenge that hinders potential translation of optogenetics in human patients. In addition, it would be advantageous to manipulate neuronal activity acutely and precisely as well as chronically and non-invasively, using the same genetic construct in animal models. We have previously addressed these challenges by employing bioluminescence and have created a new line of opto-chemogenetic probes termed luminopsins by fusing light-sensing opsins with light-emitting luciferases. In this report, we incorporated Chlamydomonas channelrhodopsin 2 with step-function mutations as the opsin moiety in the new luminopsin fusion protein termed step-function luminopsin (SFLMO). Bioluminescence-induced photocurrent lasted longer than the bioluminescence signal due to very slow deactivation of the mutated channel. In addition, bioluminescence was able to activate most of the channels on the cell surface due to the extremely high light sensitivity of the channel. This efficient channel activation was partly mediated by radiationless bioluminescence resonance energy transfer due to the proximity of luciferase and opsin. To test the utility of SFLMOs in vivo, we transduced the substantia nigra unilaterally via a viral vector in male rats. Injection of the luciferase substrate as well as conventional photostimulation via fiber optics elicited circling behaviors. Thus, SFLMOs expand the current approaches for manipulation of neuronal activity in the brain and add more versatility and practicality to optogenetics in freely behaving animals.

Original languageEnglish
Pages (from-to)422-436
Number of pages15
JournalJournal of Neuroscience Research
Issue number3
StatePublished - Mar 1 2020


  • LED
  • behavior
  • bioluminescence
  • coelenterazine
  • opsin


Dive into the research topics of 'Step-function luminopsins for bimodal prolonged neuromodulation'. Together they form a unique fingerprint.

Cite this