Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: neuroscience – Page 997

Nice paper on Neural Circuit structures.

Plasticity between neural connections plays a key role in our ability to process and store information. One of the fundamental questions on plasticity, is the extent to which local processes, affecting individual synapses, are responsible for large scale structures of neural connectivity. Here we focus on two types of structures: synfire chains and self connected assemblies. These structures are often proposed as forms of neural connectivity that can support brain functions such as memory and generation of motor activity. We show that an important plasticity mechanism, spike timing dependent plasticity, can lead to autonomous emergence of these large scale structures in the brain: in contrast to previous theoretical proposals, we show that the emergence can occur autonomously even if instructive signals are not fed into the neural network while its form is shaped by synaptic plasticity.

Citation: Ravid Tannenbaum N, Burak Y (2016) Shaping Neural Circuits by High Order Synaptic Interactions. PLoS Comput Biol 12: e1005056. doi:10.1371/journal.pcbi.1005056

Editor: Peter E. Latham, UCL, UNITED KINGDOM

Continue reading “Shaping Neural Circuits” | >

Researchers have developed a wireless device small enough to be implanted in individual nerves, and capable of detecting the electrical activity of nerves and muscles deep within the body, according to DARPA, which funded the work.

The millimeter-scale sensor and external ultrasonic transceiver that powers the implant and communicates with it is called a “neural dust” system. The team, led by the University of California, Berkeley’s Department of Electrical Engineering and Computer Sciences, completed the first in vivo tests of this technology in rodents and reported them in the journal Neuron.

The sensor can be implanted into either a nerve or muscle, and consists of a piezoelectric crystal, a single custom transistor, and a pair of recording electrodes. The system reported both electroneurogram (ENG) recordings from the sciatic nerve and electromyographic (EMG) recordings from the gastrocnemius muscle, according to the journal article.

Read more

Abstract.

Developmental dyslexia is a common disorder with a strong genetic component, but the underlying molecular mechanisms are still unknown. Several candidate dyslexia-susceptibility genes, including KIAA0319, DYX1C1, and DCDC2, have been identified in humans. RNA interference experiments targeting these genes in rat embryos have shown impairments in neuronal migration, suggesting that defects in radial cortical migration could be involved in the disease mechanism of dyslexia. Here we present the first characterisation of a Kiaa0319 knockout mouse line. Animals lacking KIAA0319 protein do not show anatomical abnormalities in any of the layered structures of the brain. Neurogenesis and radial migration of cortical projection neurons are not altered, and the intrinsic electrophysiological properties of Kiaa0319 -deficient neurons do not differ from those of wild-type neurons. Kiaa0319 overexpression in cortex delays radial migration, but does not affect final neuronal position. However, knockout animals show subtle differences suggesting possible alterations in anxiety-related behaviour and in sensorimotor gating. Our results do not reveal a migration disorder in the mouse model, adding to the body of evidence available for Dcdc2 and Dyx1c1 that, unlike in the rat in utero knockdown models, the dyslexia-susceptibility candidate mouse homolog genes do not play an evident role in neuronal migration. However, KIAA0319 protein expression seems to be restricted to the brain, not only in early developmental stages but also in adult mice, indicative of a role of this protein in brain function. The constitutive and conditional knockout lines reported here will be useful tools for further functional analyses of Kiaa0319.

Read more

Engineers at the University of California, Berkeley have created the very first dust-sized wireless sensors that may be implanted within the body. This is bringing technology closer to the day that technologies such as the Fitbit will be able to monitor internal nerves, muscles and organs all in real time.

These devices do not require batteries and may also be able to stimulate nerves and muscles opening up doors for electroceuticals to treat disorders including epilepsy and stimulate the immune system or lower inflammation.

The neural dust is implanted in the muscles and peripheral nerves of rats and is unique due to its use of ultrasound. It holds the ability to both power and read measurements. Ultrasound technology is already very thoroughly developed for the care of hospice patients and ultrasound vibrations are able to penetrate just about everywhere within the human body making them much more useful than radio waves.

Read more

Imagine a future where we can treat diabetes or autoimmune disorders with an electrical zap delivered by a device no larger than a speck of dust.

The device, implanted through microsurgery, sits silently on a single nerve bundle, monitoring electrical signals sent out by the brain to itself and various organs in the body.

When it detects a problem — a rogue misfire, or a shift in activity patterns — the device powers up, sending out counter-pulses to correct the signal. In this way, it keeps your body running smoothly and disease at bay. No pills. No injections. No pain.

Read more

(credit: NIH National Institute on Aging)

Anti-inflammatory drug mefenamic acid completely reversed memory loss and brain inflammation in mice genetically engineered to develop symptoms of Alzheimer’s disease and amyloid beta-induced memory loss, a team led by David Brough, PhD, from the University of Manchester has discovered.

The non-steroidal anti-inflammatory drug (NSAID) drug targets an important inflammatory pathway called the NLRP3 inflammasome, which damages brain cells, according to Brough. This is the first time a drug has been shown to target this inflammatory pathway, highlighting its importance in the disease model, Brough said.

Read more

A surgical procedure that involves drilling holes and injecting stem cells into stroke patients’ brains seems to have contributed to a wheelchair-bound stroke patient regaining the ability to walk. Despite the major recovery exhibited by patients, further study must be made to investigate the true impact.

Researchers from Stanford University were “stunned” at the positive results they obtained after injecting stem cells directly into stroke patients’ brains. The discovery has created a talking point in the neuroscience community, causing researchers to re-visit and re-evaluate the notion that brain damage is permanent and irreversible.

Surgical Procedure

Read more

IBM’s TrueNorth, a so-called “cognitive chip,” remarkably resembles the human brain: its 4,096 cores combine to create about a million digital neurons and 256 million synapse connections. In short, like everyone’s favorite complex organ, it operates extremely quickly and consumes far less energy than typical processors. Samsung has taken the chip and plugged it into its Dynamic Vision Sensor (DVS) to process digital imagery at a blindingly fast rate.

Typical digital cameras max out 120 frames per second, but a DVS-equipped gadget can capture an incredible 2,000 fps. Unlike a conventional sensor, each pixel on Samsung’s only reacts if it needs to report a change in what it’s seeing, according to CNET. That high speed could be useful for creating 3D maps or gesture controls. At a press event on Thursday in San Jose, the company demonstrated its ability to control a TV as it recognized hand waves and finger pinches from ten feet away.

DVS is efficient like its TrueNorth chip base, and only consumes about 300 milliwatts of power. That’s about a hundredth the drain of a laptop’s processor and a tenth of a phone’s, a Samsung VP said at the event. But we still have a ways to go before we approach the minimal power requirements of the human brain, he said, which can process some tasks at 100 million times less power than a computer.

Read more

Britain will spend more than £800million funding next-generation military technology including tiny “dragonfly drones” for gathering intelligence and laser weapons to eliminate missiles.

Michael Fallon, the Defence Secretary, will today announce an innovation unit which will encourage individuals and companies to pitch ideas to a panel of experts. The best ideas will be fast-tracked with the support of an £800million fund over the next decade.

Projects which will be funded include a “micro-drone” with tiny flapping wings inspired by the biology of a dragon fly, which could have a “huge impact” on operations in urban environments.

Read more