Table 3.
Method | Model Systems Tested | Inducible (Timescale) | Reversible (Timescale) | Inducer | Comments | References |
---|---|---|---|---|---|---|
ChR2 | Mm, MC, MBS, Dm, Ce, Ch | millseconds | milliseconds | blue light | high expression levels and light intensities required | Nagel et al., 2003; Boyden et al., 2005; Li et al., 2005 |
chARGe | MC | seconds | seconds | light | multiple transgenes required | Zemelman et al., 2002 |
ATP/Capsaicin Receptor | MC, Dm | milliseconds | seconds | UV light/caged ligand | activation by photorelease of caged ligands | Zemelman et al., 2003; Lima and Miesenbock, 2005 |
RASSL | Mm | seconds | seconds | small-molecule | limited to situations where G-protein activation depolarizes neurons | Redfern et al., 1999; Zhao et al., 2003 |
LiGluR | MC, Zf | milliseconds | milliseconds | Light/tethered small-molecule agonist | activation by cystein- conjugated tethered agonists | Szobota et al., 2007 |
SPARK | MC | milliseconds | milliseconds | Light/tethered small-molecule agonist | inactivation by cystein- conjugated tethered agonists | Banghart et al., 2004 |
Abbreviations: Ce, C. elegans; Dm, Drosophila melanogaster; Zf, zebrafish; Ch, chick; Mm, mouse; MC, mammalian cultured neurons; MBS, mammalian brain slices.