When a mammal explores an unfamiliar environment, ensembles of ‘place’ cells in the hippocampus fire individually, recording specific locations in a cognitive map that aid future spatial navigation of the area.
Once the relationship between place cell activity and location has been established, the activity of the cells can be used to predict the animal’s location within its environment. Activity patterns in the ensembles are later ‘replayed’ during rest and sleep, and neuroscientists believe this is important for consolidating the spatial memories of the new environment.
Neuroscientists also contend that the sequence of place cell firing corresponding to the new environment is established during the first exploration of that environment. Now George Dragoi and Susumu Tonegawa from the RIKEN-MIT Center for Neural Circuit Genetics at the Massachusetts Institute of Technology in Cambridge, Massachusetts, report that the activity of place cell circuits is also preconfigured to encode novel environments.
Dragoi and Tonegawa recorded the activity patterns of place cells in the CA1 region of the hippocampus while mice navigated a familiar environment. They also recorded from the same cells afterwards, while the mice rested or slept. As expected, some of the place cell activity patterns they observed corresponded to the familiar environment that the animals had explored, but they also recorded new patterns from place cells that were previously silent.
The researchers found that the novel activity patterns corresponded strongly to the sequences of place cell firing that were recorded when the mice subsequently explored an unfamiliar part of the environment (Fig. 1). This suggests that the activity patterns represent ‘preplay’ of the unexplored locations rather than replay of the familiar part of the environment. Thus, the activity of hippocampal place cells appears not only to consolidate spatial memories of newly experienced environments, but also to predict how novel, unexplored environments can be encoded when they are navigated in the future. The researchers also suggest that hippocampal preplay may accelerate spatial memory formation once the novel environment is eventually explored.
“Encoding of new information makes use of the pre-existing organization of the hippocampal network, and will stabilize faster compared to a case when the neuronal network has to re-organize to a new state that does not resemble the pre-existing one,” says Dragoi. “In an immediate follow-up to this study, we will address the role of the intact hippocampal circuitry in the mechanisms and dynamics of the preplay phenomenon,” he adds.
The corresponding author for this highlight is based at the RIKEN_MIT Center for Neural Circuit Genetics
 Dragoi, G. & Tonegawa, S. Preplay of future place cell sequences by hippocampal cellular assemblies. Nature 469, 397–401 (2011).
gro-pr | Research asia research news
Bolstering fat cells offers potential new leukemia treatment
17.10.2017 | McMaster University
Ocean atmosphere rife with microbes
17.10.2017 | King Abdullah University of Science & Technology (KAUST)
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
17.10.2017 | Life Sciences
17.10.2017 | Life Sciences
17.10.2017 | Earth Sciences