TABLE 2

In vivo applications of optogenetics

OpsinExpression PatternPrincipal FindingsReference
Mice
    ChR2Spinal neurons in and around phrenic motor poolPhotostimulation rescues diaphragmatic respiratory motor activity in mice with cervical spinal cord injuries and induces plastic and adaptive changes to enable motor activity in the absence of lightAlilain et al., 2008
Layer 2/3 pyramidal neurons in somatosensory cortexMice learned to detect optical stimulation and to make decisions based on the presence or absence of the resultant cortical activityHuber et al., 2008
Pyramidal cells of lateral amygdalaOptical stimulation of lateral amygdala is sufficient to induce fear learning; mice learned to freeze in response to a tone that was paired with photoactivationJohansen et al., 2010
Dopaminergic neurons in ventral tegmental areaPhasic stimulation was sufficient to drive behavioral conditioning and elicited dopamine transientsTsai et al., 2009
Cortical interneuronsDeveloped PINP: can use ChR2 to “tag” neurons and monitor their activityLima et al., 2009
Cortical and thalamic pyramidal neuronsNeuronal activation induces local blood oxygenation level-dependent signals on fMRI; optogenetic fMRI demonstrates causal effects—can visualize and map downstream neural activityLee et al., 2010
Astrocytes in brainstem chemoreceptor areasActivating astrocytes activated the chemoreceptor neurons in an ATP-dependent manner and caused a respiratory response, thus demonstrating a role of glia in a physiological reflexGourine et al., 2010
Neuronal subsets throughout brainMapped spatial distribution of neural circuits in cortexWang et al., 2007
Hypocretin neuronsDirectly activating hypocretin neurons via ChR2 increased probability of awakening from slow-wave or REM sleepAdamantidis et al., 2007
Prefrontal cortexStimulation of ChR2 has antidepressant-like effects in mice previously exposed to chronic social defeat stressCovington et al., 2010
Central amygdalaTwo simultaneous papers mapped the microcircuitry required for conditioned fearCiocchi et al., 2010; Haubensak et al., 2010
    Optin-receptor chimerasNucleus accumbensOpto-β1AR induced conditioned place preference, but activation of ChR2 or opto-β2AR did notAiran et al., 2009
Drosophila
    ChR2Abnormal chemosensory jump 6 neuronsThese neurons are required for startle response and mediate escape behavior; stimulation of cells with ChR2 elicited escape in response to lightZimmermann et al., 2009
Olfactory receptor neurons in larvaeStimulation caused illusion of attractive odor with associated crawling toward the stimulusBellmann et al., 2010
Subset of Rohon-Beard and trigeminal somatosensory neuronsInducing a single action potential generates escape behavior; first demonstration of electrical activation of single cells in unrestrained zebrafish; determined that endogenous ATR is sufficientDouglass et al., 2008
Zebrafish
    NpHR, eNpHR, ChR2Throughout brainLocalized swim command circuitry to hindbrain region; activating eNpHR in this region caused larvae to stop moving and lose coordination, while activating ChR2 elicited swimming behaviorArrenberg et al., 2009
    NpHR, ChR2Throughout brainMapped eye moments that follow visual stimulus; ChR2 activation can restore saccades in a genetic mutant that does not normally exhibit them; determined that saccade circuit in zebrafish is similar to mammalian burst generatorSchoonheim et al., 2010
    ChR2Olfactory bulb, ventral telencephalonAdapted tet system and viral gene delivery to zebrafish; ChR2 activation induced forward and backward swimmingZhu et al., 2009
  • PINP, photostimulation-assisted identification of neuronal populations; fMRI, functional magnetic resonance imaging; ATR, all-trans retinol.