Malinow and his colleagues induced fear conditioning by giving the rats small electric shocks while using high frequency pulses of laser light to activate the amygdala neurons. They thus learned to associate the shock with the pulses of light, so that they would respond with fear to the light pulses alone, and when the researchers examined their brains, they found that the light pulses had successfully induced LTP in the amygdala.
Crucially, the researchers also found that a different pattern of light pulses delivered to the same cells could abolish LTP by inducing an opposing mechanism called long-term depression in the same synapses. This made the animals “forget” the association between the light pulses and electric shocks, so that they were no longer scared of the pulses, but this “erasure” was reversible – if the first pattern of pulses was delivered a second time, it induced LTP once again and reactivated the memory.
“We were playing with memory like a yo-yo,”
Has anyone noticed the light pulses now emitting from popular web sites and e mail platforms
recently?
Flashes of light, for what reason?
Researchers will not only stimulate nerves with jolts of electricity, they’ll also use pulses of light, sound waves, and magnetic fields.