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Alternating sequences of future and past behavior encoded within hippocampal theta oscillations

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Representing the past and the future

Adaptive behavior requires the ability to analyze experience both prospectively and retrospectively. How can forward-ordered neural activity facilitate the storage or expression of reverse-ordered sequences? Wang et al. used multitetrode recordings from many individual hippocampal CA1 neurons in rats while simultaneously recording field potentials expressing theta oscillations. Spatial representation in the place cell network oscillated between forward and backward sweeps within each theta oscillation. Backward replay was associated with theta peaks, whereas forward replay was associated with theta troughs. Most cells fell into one category, but some corresponding to deep-layer neurons showed bimodular responses. Backward replay was driven by entorhinal inputs, whereas forward replay was evoked by CA3 inputs. These are important insights into the underlying basis of coding future and past experiences.

Science, this issue p. 247

Abstract

Neural networks display the ability to transform forward-ordered activity patterns into reverse-ordered, retrospective sequences. The mechanisms underlying this transformation remain unknown. We discovered that, during active navigation, rat hippocampal CA1 place cell ensembles are inherently organized to produce independent forward- and reverse-ordered sequences within individual theta oscillations. This finding may provide a circuit-level basis for retrospective evaluation and storage during ongoing behavior. Theta phase procession arose in a minority of place cells, many of which displayed two preferred firing phases in theta oscillations and preferentially participated in reverse replay during subsequent rest. These findings reveal an unexpected aspect of theta-based hippocampal encoding and provide a biological mechanism to support the expression of reverse-ordered sequences.

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SpaceX launches Starlink app and provides pricing and service info to early beta testers

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SpaceX has debuted an official app for its Starlink satellite broadband internet service, for both iOS and Android devices. The Starlink app allows users to manage their connection – but to take part you’ll have to be part of the official beta program, and the initial public rollout of that is only just about to begin, according to emails SpaceX sent to potential beta testers this week.

The Starlink app provides guidance on how to install the Starlink receiver dish, as well as connection status (including signal quality), a device overview for seeing what’s connected to your network, and a speed test tool. It’s similar to other mobile apps for managing home wifi connections and routers. Meanwhile, the emails to potential testers that CNBC obtained detail what users can expect in terms of pricing, speeds and latency.

The initial Starlink public beta test is called the “Better than Nothing Beta Program,” SpaceX confirms in their app description, and will be rolled out across the U.S. and Canada before the end of the year – which matches up with earlier stated timelines. As per the name, SpaceX is hoping to set expectations for early customers, with speeds users can expect ranging from between 50Mb/s to 150Mb/s, and latency of 20ms to 40ms according to the customer emails, with some periods including no connectivity at all. Even with expectations set low, if those values prove accurate, it should be a big improvement for users in some hard-to-reach areas where service is currently costly, unreliable and operating at roughly dial-up equivalent speeds.

Image Credits: SpaceX

In terms of pricing, SpaceX says in the emails that the cost for participants in this beta program will be $99 per moth, plus a one-time cost of $499 initially to pay for the hardware, which includes the mounting kit and receiver dish, as well as a router with wifi networking capabilities.

The goal eventually is offer reliably, low-latency broadband that provides consistent connection by handing off connectivity between a large constellation of small satellites circling the globe in low Earth orbit. Already, SpaceX has nearly 1,000 of those launched, but it hopes to launch many thousands more before it reaches global coverage and offers general availability of its services.

SpaceX has already announced some initial commercial partnerships and pilot programs for Starlink, too, including a team-up with Microsoft to connect that company’s mobile Azure data centers, and a project with an East Texas school board to connect the local community.

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Erratum for the Report “Meta-analysis reveals declines in terrestrial but increases in freshwater insect abundances” by R. Van Klink, D. E. Bowler, K. B. Gongalsky, A. B. Swengel, A. Gentile, J. M. Chase

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S. Rennie, J. Adamson, R. Anderson, C. Andrews, J. Bater, N. Bayfield, K. Beaton, D. Beaumont, S. Benham, V. Bowmaker, C. Britt, R. Brooker, D. Brooks, J. Brunt, G. Common, R. Cooper, S. Corbett, N. Critchley, P. Dennis, J. Dick, B. Dodd, N. Dodd, N. Donovan, J. Easter, M. Flexen, A. Gardiner, D. Hamilton, P. Hargreaves, M. Hatton-Ellis, M. Howe, J. Kahl, M. Lane, S. Langan, D. Lloyd, B. McCarney, Y. McElarney, C. McKenna, S. McMillan, F. Milne, L. Milne, M. Morecroft, M. Murphy, A. Nelson, H. Nicholson, D. Pallett, D. Parry, I. Pearce, G. Pozsgai, A. Riley, R. Rose, S. Schafer, T. Scott, L. Sherrin, C. Shortall, R. Smith, P. Smith, R. Tait, C. Taylor, M. Taylor, M. Thurlow, A. Turner, K. Tyson, H. Watson, M. Whittaker, I. Woiwod, C. Wood, UK Environmental Change Network (ECN) Moth Data: 1992-2015, NERC Environmental Information Data Centre (2018); .

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Max Q: NASA makes key discovery for future of deep space exploration

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Max Q is a weekly newsletter from TechCrunch all about space. Sign up here to receive it weekly on Sundays in your inbox.

This past week, we unveiled the agenda for TC Sessions: Space for the first time. It’s our inaugural event focused on space startups and related technologies, and it’s happening December 16 and 17. It’s entirely virtual, of course, and the good news is that means you can attend easily from anywhere in the world.

We’ve got an amazing lineup, including newsmakers we regularly cover here. NASA Administrator Jim Bridenstine will be there, as well as U.S. Space Force commanding office Jay Raymond, and Rocket Lab CEO Peter Beck, to name just a few. Tickets are available now, so sign up ASAP to get the best price possible.

SpaceX launched not one, but two separate Falcon 9 rockets loaded with Starlink satellites for its broadband internet service last week. The first took off on October 19, then just five days later, another full complement reached orbit. SpaceX has now launched nearly 1,000 of these, and it must be getting awfully close to kicking off its public beta of the consumer-facing internet service.

OSIRIS-REx probe 'tagging' the surface of asteroid Bennu

Image Credits: NASA

NASA has managed to collect a sample from the surface of an asteroid in a first for the agency. The sample collection came courtesy of NASA’s OSIRIS-REx robotic exploration probe, which was built by partner Lockheed Martin. OSIRIS-REx still has some work to do at Bennu, the asteroid from which it collected the sample, but next year it’ll begin heading back with its precious cargo intended for study by scientists here on Earth.

NASA is full of special discoveries this week – scientists working on its SOFIA imaging project confirmed the presence of water on the surface of the Moon that’s exposed to sunlight. They’d suspected it was there previously, but this is the first confirmed proof, and while it isn’t a whole lot of water, it could still change the future of human deep space exploration.

Image Credits: Microsoft

Microsoft looks primed to invest in space-based business in a big way with Azure Space, a new business unit it formed to handle all space-related businesses attached to its cloud data efforts. That includes a new type of deployable mobile datacenter that will be connected in part via SpaceX’s Starlink global broadband network, putting computing power near where it’s needed in a scalable way.

Intel has loaded up a small satellite with a power-efficient edge AI processor, its Myriad 2 Vision Processing Unit. That’ll help the satellite do its own on-board classification of images of Earth that it takes, saving key bandwidth for what it transfers back to researchers on the ground. Local AI could help satellite networks in general operate much more efficiently, but it’s still in its infancy as a field.

Image Credits: Relativity Space

Relativity Space has tons of promise in terms of its 3D-printed rockets, but it still hasn’t actually reached the launch stage. It did however secure a key government contract, with Lockheed Martin selecting its rocket for a forthcoming mission to test fluid management systems for NASA.

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