When retinal is not added to the food, larvae expressing Crei\ChR2^Scer\UAS.cSa via Scer\GAL4^RapGAP1-OK6 display no discernible reaction to photostimulation, as measured by the degree of immobilization. When retinal is added, light application induces reversible muscle paralysis, with the duration of immobilization scaling with light intensity.

Even high intensity light fails to immobilize adult flies expressing Crei\ChR2^Scer\UAS.cSa via Scer\GAL4^RapGAP1-OK6.

In larvae expressing Crei\ChR2^Scer\UAS.cSa via Scer\GAL4^VGlut-OK371, 470-nm light triggers EJPs but only after relatively long light pulses (16 ms); 617-nm light pulses do not trigger EJPs in these animals.

Flies expressing Crei\ChR2^Scer\UAS.cSa (a blue light-gated ion channel channelrhodopsin) under the control of Scer\GAL4^Gr5a.5.156 show an attraction response to blue light when placed in an optogenetic T-maze containing blue and yellow light-emitting diodes. This response is not altered upon removal of the antennae. Flies expressing Crei\ChR2^Scer\UAS.cSa under the control of Scer\GAL4^Gr21a.9.323 avoid blue light, and this response is impaired upon removal of the antennae.

Flies expressing Crei\ChR2^Scer\UAS.cSa (a blue light-gated ion channel channelrhodopsin) in PN[[v]]-1 neurons (under the control of Scer\GAL4^VT1606 or Scer\GAL4^VT48643) show an avoidance response to blue light when placed in an optogenetic T-maze containing blue and yellow light-emitting diodes. A similar avoidance response is seen when Crei\ChR2^Scer\UAS.cSa is expressed in PN[[v]]-2 neurons under the control of Scer\GAL4^NP7243 and this response was not altered by removing the antennae.

Flies expressing Crei\ChR2^Scer\UAS.cSa (a blue light-gated ion channel channelrhodopsin) in PN[[v]]-3 neurons under the control of Scer\GAL4^VT12760 show an impaired avoidance response to 0.5% CO[[2]]. No effect is seen on the avoidance response to 2% CO[[2]].

Activation of Crei\ChR2^Scer\UAS.cSa by spaced blue light stimulation in animals expressing Crei\ChR2^Scer\UAS.cSa under the control of Scer\GAL4^futsch-C380 results in a 2.5-fold increase in the number of "ghost boutons" (axon terminal extensions with synaptic vesicles but lacking active zones and postsynaptic structures) per neuromuscular junction compared to controls.

Blue light stimulation of octopaminergic neurons expressing Crei\ChR2^Scer\UAS.cSa, under the control of Scer\GAL4^Tdc2.PC, results in a significant increase in locomotor speed in response to starvation.

Expression of Crei\ChR2^Scer\UAS.cSa under the control of Scer\GAL4^{Or83b.2.642.T:Hsim\VP22} increases response index to blue light-induced stimulation, indicating overexpression larvae are now more attracted (or less repelled) by blue light. Application of white light also induces a repression of the negative phototactic behavior of transgenic larvae.

Expression of Crei\ChR2^Scer\UAS.cSa under the control of Scer\GAL4^{Or83b.2.642.T:Hsim\VP22} does not lead to adaptation of ORNs to prolonged blue light stimulation nor prevent the animals from perceiving an additional odor stimulus.

Transgenic larvae expressing Crei\ChR2^Scer\UAS.cSa under the control of Scer\GAL4^Or33b.PC, Scer\GAL4^Or45a.PC, Scer\GAL4^Or45b.PC, Scer\GAL4^Or59a.PF, Scer\GAL4^Or67b.PC, Scer\GAL4^Or74a.PC, Scer\GAL4^Or85c.PC, or Scer\GAL4^Or94b.PC are less attracted to dark quadrants (in orientation assays) than wild-type larvae. These flies also show a stronger negative phototaxis effect with blue light rather than white light (this wasn't seen with Scer\GAL4^Or33b.PC and Scer\GAL4^Or45a.PC drivers).

Transgenic larvae expressing Crei\ChR2^Scer\UAS.cSa under the control of Scer\GAL4^Or33b.PC, Scer\GAL4^Or45a.PC, Scer\GAL4^Or45b.PC, Scer\GAL4^Or59a.PF, Scer\GAL4^Or67b.PC, Scer\GAL4^Or74a.PC, Scer\GAL4^Or85c.PC, or Scer\GAL4^Or94b.PC avoid octyl acetate, as in wild-type.

Expression of Crei\ChR2^Scer\UAS.cSa under the control of Scer\GAL4^Or33b.PC or Scer\GAL4^Or45a.PC results in an aversion response to blue light.

MN30-Ib neurons expressing Crei\ChR2^Scer\UAS.cSa under the control of Scer\GAL4^C380 depolarise and fire spikes when exposed to blue light.

Expression of Crei\ChR2^Scer\UAS.cSa under the control of Scer\GAL4^OK371 generates excitatory junctional potentials (EJPs) at the larval neuromuscular junction in response to 200ms blue light pulses.

Larvae expressing Crei\ChR2^Scer\UAS.cSa under the control of Scer\GAL4^OK371 under constant blue light illumination do not show significantly different crawling speeds from control larvae. The crawling speed of these larvae when exposed to pulsed blue light is not significantly different from that of controls.

Larvae expressing Crei\ChR2^Scer\UAS.cSa under the control of Scer\GAL4^5-40 and exposed to constant blue light crawl significantly more slowly than controls immediately after the onset of illumination, but by 30 seconds after the onset of illumination, crawling speeds are not different from those of controls.

Larvae expressing Crei\ChR2^Scer\UAS.cSa under the control of Scer\GAL4^5-40 and exposed to rhythmic blue light show a significant inhibition of crawling for the entire 2 minute stimulation period, in contrast to controls.

When subjected to light stimulation, motorneurons of larvae expressing Crei\ChR2^Scer\UAS.cSa by Scer\GAL4^C380 potentiates mEJP (spontaneous excitatory potentials) frequency on average to the same level as nerve stimulation, lasting 2-3 hours, and induces structural synaptic changes including the formation of "ghost boutons" - boutons containing synaptic vesicles but lacking active zones and presynaptic structures.

Larvae expressing Crei\ChR2^Scer\UAS.cSa panneuronally (driven by Scer\GAL4^elav.PLu) or in motorneurons (driven by Scer\GAL4^D42) show light-induced body contractions

at 0.64 mW/mm², whereas larvae expressing Crei\ChR2^Scer\UAS.cSa in dopaminergic neurons (driven by Scer\GAL4^Tdc2.PC) do not. In larvae expressing Crei\ChR2^Scer\UAS.cSa in motorneurons, driven by Scer\GAL4^D42, short light pulses (100 ms) evoke single excitatory junction potentials (EJPs).

Blue light illumination but not red light illumination impairs chemotaxis toward 3-octanol if Crei\ChR2^Scer\UAS.cSa is expressed in motorneurons, under the control of Scer\GAL4^D42. This effect is fully reversible and is not seen when Crei\ChR2^Scer\UAS.cSa is expressed in octopaminergic/tyraminergic neurons, under the control of Scer\GAL4^Tdc2.PC, or in dopaminergic neurons, under the control of Scer\GAL4^ple.PF.

Larvae expressing Crei\ChR2^Scer\UAS.cSa under the control of Scer\GAL4^Tdc2.PC show the same appetitive memory after pairing one of two odors (n-amylacetate and 3-ocatnol) with fructose seen in control larvae. When light stimulation is used instead of the fructose reward during training, Scer\GAL4^Tdc2.PC>Crei\ChR2^Scer\UAS.cSa larvae show appetitive memory while control larvae do not. Similarly, when light substitutes the NaCl reinforcer during training, Scer\GAL4^ple.PF>Crei\ChR2^Scer\UAS.cSa larvae show aversive memory while control larvae do not.

Crei\ChR2^UAS.cSa, Scer\GAL4^ChAT.7.4, VAChT^-Q.UAS has abnormal neurophysiology | third instar larval stage | conditional phenotype

Crei\ChR2^UAS.cSa, Scer\GAL4^ChAT.7.4, VAChT^UAS.cCa has abnormal neurophysiology | third instar larval stage | conditional phenotype

Crei\ChR2^UAS.cSa, Scer\GAL4^ChAT.7.4, VAChT^-Q.UAS has embryonic/larval motor neuron | third instar larval stage | conditional phenotype

Crei\ChR2^UAS.cSa, Scer\GAL4^ChAT.7.4, VAChT^UAS.cCa has embryonic/larval motor neuron | third instar larval stage | conditional phenotype