The emerging field of optogenetics uses several bacterial opsins to control cellular functions in genetically modified cells. For example, neuronal signaling is achieved by membrane depolarization that results in subsequent activation of transient electrical signals (spiking). By exogenously expressing light-activated proteins that alter membrane potential in neurons, addition or removal of specific wavelengths of light can be used for rapid control of neuronal activity.

Chemogenetic models express engineered receptors that are activated by designer drugs.  These can be used to control neuronal signaling in a genetically specified neuronal subset by providing the artificial ligand.

A growing number of mouse lines expressing proteins that activate, inhibit or detect neuronal activity are available from The Jackson Laboratory Repository.

Cre-dependent optogenetic tools

A number of these strains express optogenetic effector proteins in a cre-dependent manner. Cre-dependent optogenetic tool strains can be mated with any one of the many cre-expressing strains that are available to create a novel experimental system (Madisen et al. 2012, Zariwala et al. 2012). To find an appropriate cre line for your application, see our list of cre strains for neurobiology or www.creportal.org.