eyeoneblack
12th February 2011, 04:16 PM
Researchers at MIT performed experiments on mice such that the firing of 'place cells' in an area of the hippocampus could be recorded. Excerpts from the actual article follow but in plain speech (as best I can make of it) 'place cells' relate to the brains mapping of a trajectory through space - simply running down a track. At rest or slow wave sleep these place cells fire again to consolidate the memory.
By elaborate means and statistical fortitude the scientists were able to show that not only did the place cells fire to consolidate a known memory but others fired relating to a track they hadn't seen yet. They went so far as to record place cell sequences in mice who had no track experience at all and were isolated in a box that correlated to a track in the same room but not visible to them. In other words, the mice recorded the experience before they encountered the track. They call this PREPLAY as opposed to replay.
How can we account for this? The researchers don't speculate as to HOW, but it seems to me the simplest explanation would be that the tracks were not actually hidden from the mice if the mice could explore them in a non-physical body. That the mice exhibited an 'otherwhereness' of awareness.
The following is excerpted from nature magazine 20 Jan 2011
Preplay of future place cell sequences by hippocampal cellular assemblies
George Dragoi and Susumu Tonegawa
Department of Brain and Cognitive Sciences, MIT
During spatial exploration, hippocampal neurons show a sequential firing pattern in which individual neurons fire specifically at particular locations along the animal's trajectory (place cells).[¶ inserted for readability]
According to the dominant model of hippocampal cell assembly activity, place cell firing order is established for the first time during exploration, to encode the spatial experience, and is subsequently replayed during rest or slow-wave sleep for consolidation of the encoded experience.[¶]
Here we report that temporal sequences of firing of place cells expressed during a novel spatial experience occurred on a significant number of occasions during the resting or sleeping period preceding the experience.[¶]
[from the body of the article]
We have demonstrated that a significant number of temporal firing sequences of CA1 cells during resting periods of a familiar track exploration that preceded a novel track exploration in the same general environment were correlated with the place cell sequences of the novel track rather than the familiar track. This phenomenon, preplay, is temporally opposite to the process of replay, when activity during rest or sleep periods recapitulates place cell sequences that have already occurred during previous exploration. Preplay differs fundamentally from replay because it occurs before exploration of novel tracks.
http://www.nature.com/nature/journal/v4 ... 09633.html (http://www.nature.com/nature/journal/v469/n7330/full/nature09633.html)
By elaborate means and statistical fortitude the scientists were able to show that not only did the place cells fire to consolidate a known memory but others fired relating to a track they hadn't seen yet. They went so far as to record place cell sequences in mice who had no track experience at all and were isolated in a box that correlated to a track in the same room but not visible to them. In other words, the mice recorded the experience before they encountered the track. They call this PREPLAY as opposed to replay.
How can we account for this? The researchers don't speculate as to HOW, but it seems to me the simplest explanation would be that the tracks were not actually hidden from the mice if the mice could explore them in a non-physical body. That the mice exhibited an 'otherwhereness' of awareness.
The following is excerpted from nature magazine 20 Jan 2011
Preplay of future place cell sequences by hippocampal cellular assemblies
George Dragoi and Susumu Tonegawa
Department of Brain and Cognitive Sciences, MIT
During spatial exploration, hippocampal neurons show a sequential firing pattern in which individual neurons fire specifically at particular locations along the animal's trajectory (place cells).[¶ inserted for readability]
According to the dominant model of hippocampal cell assembly activity, place cell firing order is established for the first time during exploration, to encode the spatial experience, and is subsequently replayed during rest or slow-wave sleep for consolidation of the encoded experience.[¶]
Here we report that temporal sequences of firing of place cells expressed during a novel spatial experience occurred on a significant number of occasions during the resting or sleeping period preceding the experience.[¶]
[from the body of the article]
We have demonstrated that a significant number of temporal firing sequences of CA1 cells during resting periods of a familiar track exploration that preceded a novel track exploration in the same general environment were correlated with the place cell sequences of the novel track rather than the familiar track. This phenomenon, preplay, is temporally opposite to the process of replay, when activity during rest or sleep periods recapitulates place cell sequences that have already occurred during previous exploration. Preplay differs fundamentally from replay because it occurs before exploration of novel tracks.
http://www.nature.com/nature/journal/v4 ... 09633.html (http://www.nature.com/nature/journal/v469/n7330/full/nature09633.html)