"Millisecond-timescale, genetically targeted optical control of neural activity"
http://www.nature.com/neuro/journal/v8/n9/full/nn1525.html
what they did:
- expressed ChR2 receptor in cultured hippocampal neurons.
- ChR2 is a rapidly-gated light-sensitive cation channel recently isolated from unicellular green alga
- cells were transfected via lentivirus
- caused spiking in cells by exposing them to 5-15ms flashes of blue light.
- stimulation was reliable to 30hz
- stimulated spikes had low jitter - 2ms or so.
- light stimulation protocol was robust across different neurons.
- expression of the light-gated channel did not alter the properties of the neurons or their health etc.
- they think it might be applicable to in-vivo mamalian studies!
- Subthreshold!
- for many cellular and systems neuroscience processes subthreshold depolarizations convey physiologically significant information.
- the neurons in c.elegans do not spike!
- subthreshold depolarizations are potent for activating synapes-to-nucleus signaling
- the relative timing of subthreshold and suprathreshold depolarizations can determine the direction of synaptic plasticity.
- subthreshold depolarizations operate in the more linear regime of membrane voltage
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