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anatomy of brain

Researchers figure out why we remember some incidents for a long time and forget some

It often happens that we can remember something which occurred long back but forget the incident that took place recently. Some memories remain stable while others fade away in minutes.

Researchers from Caltech have found that the memories which remain stable over time are encoded by a group of neurons firing in synchrony thus providing redundancy. The work also tries to understand the effects on memory after tragic events such as brain damage or Alzheimer’s disease.

The experiments were carried out in the laboratory of Carlos Lois, a biology professor and affiliated faculty member of Tianqiao and Chrissy Chen Institute for Neuroscience. It appears in the Science journal.

The team was led by Walter Gonzalez, a postdoc scholar. A test was developed for testing the neural activity of mice when they learn and remember a new place. The mouse was kept in a straight enclosure of length 5 feet. Different symbols were marked in different locations on the walls such as a bold plus sign at the rightmost end and angled slash close to the center. Sugar water was placed at the track ends. As the mouse explored places, the activities of certain neurons in the hippocampus were tracked by the scientists.

When initially placed in the track, the mouse wandered till it found the sugar water. Single neurons were activated when it spotted a symbol on the wall. However, on staying longer, the mouse remembered the sugar locations. As the familiarity increased more neurons got activated in synchrony as it spotted the symbols.

To understand the fading of memories, the mice were kept away from the track for 20 days. On getting back to the track, the mice which had strong memories encoded by high numbers of neurons remembered the task easily. So when large groups of neurons encode an activity, the memories can be easily recalled even if some showed different activity or remained silent.

This can be explained in a way similar to how a long story is remembered. For remembering a long story, it can be told to many different people and when all of them gather each can fill in the gaps which the other member has forgotten. By repeating this every time, the story can be preserved with the strengthening of the memory. In a similar way, neurons help each other in encoding memories which stay over time.

Impairment of memory in any form can affect us a lot since our life is basically driven by memories. Senior citizens get affected by this as a part of the aging process. Alzheimer’s disease also has devastating effects which paralyze even the basic daily functioning of a person. When memory is encoded by fewer neurons it can be forgotten easily. As a result of this, treatments which increase the recruitment of a large number of neurons for encoding a memory help in preventing memory loss.

When an activity is practiced a lot, there are more chances of remembering it as more neurons are encoded for the action. It is usually considered that to make a memory stable, individual connections to a neuron have to be strengthened. However, the study suggests that the memory can be stored for a long period of time with an increase in the neurons which encode it.

Research Paper: Persistence of neuronal representations through time and damage in the hippocampus

Culture of rat brain cells

Researchers develop technology to control the brain cells with help of smartphone

A group of researchers in the United States and Korea have invented a device which can control neural circuits with the help of a small brain implant which is controlled by a smartphone. Scientists believe that this device can amplify the efforts to detect brain diseases like Alzheimer’s, Parkinson’s, migraine and depression. With the help of replaceable drug cartridges similar to LEGO and Bluetooth low-energy, this device can target the specific neurons for prolonged periods using drug and light. The study was published in Nature Biomedical Engineering journal.

Raza Qazi, a scientist with Korea Advanced Institute of Science and Technology (KAIST) and University of Colorado Boulder said that the wireless neural device enables optical and chemical neuromodulation which has been achieved for the first time. This technology overshadows the normal methods used by researchers which generally involve optical fibers and metal tubes for delivering light and drugs. It limits the subject’s movement due to physical connections with the heavy equipment and causes a lesion in soft brain tissue due to their rigid structure. Hence they are not suitable for long-term implantation. Efforts were put to mitigate the adverse tissue response with the incorporation of wireless platforms and soft probes however they could not deliver drugs for a prolonged time period.

For achieving chronic wireless drug delivery, researchers had to solve the challenge of evaporation and exhaustion of drugs. They invented a neural device having a replaceable drug cartridge that allowed to study the brain circuits without worrying about the factor of drug exhaustion. These drug cartridges were assembled for brain implantation in mice with an ultrathin probe which had microfluidic channels, LEDs for unlimited light delivery and drug doses.

Researchers controlled it with a user interface on a smartphone and could trigger any combination of light and drug deliveries in any implanted animal without being present in a laboratory. They could also set up automated animal studies where an animal’s behavior could affect other animals’ behavior due to the conditional triggering of drug and light delivery. This revolutionary equipment is possible due to complex electronics design and powerful nanoscale engineering. It would help scientists in several ways. It would also help to dissect the neural circuit basis of behavior and understand how neuromodulators control behavior in several ways. It would also help researchers develop therapeutics for emotional and addiction disorders.

KAIST researchers developed soft electronics for implantable devices and University of Washington scientists study brain circuits which are responsible for addiction, pain, stress. This global collaboration for three years made it possible to develop the powerful brain implant in mice which can speed up the detection of brain diseases. It was supported by grants from the National Research Foundation, Korea, National Institute of Health in the US, National Institute on Drug Abuse.

neuralink elon musk

Elon Musk’s Neuralink Says That It’s Created Brain Reading Threads

Neuralink is Elon Musk’s secretive company which develops brain-machine interface, showed off its technology to the public for the first time. The goal of the company is to begin implanting devices in paralyzed humans which allows them to control phones or computers.

The first big advance is flexible “threads,” which are less likely to damage the brain than the materials currently used in brain-machine interfaces. These threads also create the possibility of transferring a higher volume of data, according to a white paper credited to “Elon Musk & Neuralink.” The abstract notes that the system could include “as many as 3,072 electrodes per array distributed across 96 threads.”

The threads are 4-6 micrometres thin which is thinner than human hair, another advantage being that the machine automatically embeds them.

Elon Musk gave a presentation not for creating a hype but encouraged people to apply for work for Neuralink. Scientists from Neuralink hope to use a laser beam through the skull instead of the traditional method of drilling holes through the skull. After conducting prior experiments they hope to have this in human patients by the end of next year. Elon Musk also revealed the result that a monkey was able to control a computer with its brain. He added that it is not suddenly that Neuralink will have a neural lace and take over people’s brain but ultimately wants to create a technology which allows merging with AI.

Matthew Nagle was the first person with spinal cord paralysis to receive brain implant which allowed him to control a computer cursor back in 2006 and also played Pong using only his mind. As a part of the research, paralyzed people with implants have moved robotic arms and brought objects into focus by a system called BrainGate.

Neuralink has emerged as a result of a long history of academic research and that no existing technology is in lines with the company’s goal of reading neural spikes. BrainGate relied on Utah Array which are stiff needles with 128 electrode channels which meant less data being picked up and stiffer channels. This problem has been solved by using a thinner polymer in Neuralink.

Neuralink technology is difficult to implant precisely but to combat the difficulty they have developed a neurosurgical robot capable of inserting 192 electrodes per minute. It also avoids blood vessels, which may lead to less of an inflammatory response in the brain. Bandwidth is a problem for interacting with AI as you can take in information more quickly than you can push it out via voice but you are already connected to the machine so this system allows quick communication with machines directly from the brain.

Right now the chip can only communicate data with a wired connection but their ultimate goal is to create a system to work wirelessly. The wireless product called the N1 SENSOR will transmit data wirelessly and Nerualink plans to implant 4 of these in the brain with 3 in motor areas and 1 in the somatosensor area and will be connected to a device mounted behind the ear. This will eliminate the need for general anaesthesia through non-invasive experience however there is a whole FDA process to be done. It is currently testing on rats to check the stability of the system and ensuring high bandwidth brain connection and flexible threads to make it record more neurons and precise outcomes.

reward structures in the human brain

Researchers establish links between aging and changes in cognitive abilities of brain networks

In a recent paper published by the researchers, it has been revealed that the functional regions that are present in the brain get less distinct and interconnected with the increase in age. This occurs mainly in the networks related to cognition and attention span. The study has been published in the Journal Of Neuroscience.

Juan Helen Zhou, an Associate Professor and a neuroscientist from Duke-NUS’ Neuroscience and Behavioural Disorders program said that compared to various cross-sectional studies, it is very crucial to understand the changes in brain which take place both due to healthy and pathological aging so as to reduce the rate of cognitive aging.

The human brain has different segregated neuronal networks with very dense internal connections and less inter-connectivity. Aging is considered to be related to decreased functional specialization and separation of the brain networks.

Professor Michael Chee, Director of Duke-NUS’ Centre for Cognitive Neuroscience and Professor Zhou led a team of neuroscientists for this research. For the same purpose, neuropsychological assessments and functional MRI was performed on a group of  57 young adults and 72 healthy elderly Singaporeans. This accumulation of data for research was done over a span of 4 years where the participants were judged on the basis of various tasks like rate of information processing, how good can participants focus. They checked their ability to memorize verbal and visuospatial data along with planning and execution of tasks.

The accretion of those fMRI images was just one part of the research. Dr. Joanna Chong, the first author of the paper and a Ph.D. graduate under Associate Professor Zhou, was given the responsibility to convert the images into much appealing graphical representations helping them to analyze the intra- and inter-network joins in the brain for the individuals which comprised of adult along with elderly generation.

This analysis aided the team in understanding that there are some functions of brain such as goal-oriented thoughts and deciding where to focus attention which gets affected as one ages, since information transferring becomes less efficient and less distinctive.

We can be assured that this research study surely has some promising future applications since aging has been the reason for various neurodegenerative and cerebrovascular diseases which are a concern for both Governments and healthcare departments. Thus, any sort of future work will facilitate in knowing the reasons for aging and will also help in deciphering the ways of preserving and curing it. Researchers have next plans to examine how factors such as genetic, cardiovascular risks, might influence the age-related changes in the brain networks.

Neonatal intensive-care unit

Researchers find music beneficial for the development of brains of premature infants

Even before birth, human beings can listen to music. In addition to it, babies in the intensive care unit have a very sensitive ear. This can have a negative effect on their growing brains as the noises of the surroundings can bring unexpected stress.

It has been estimated that almost half of the babies born before the 32nd week in pregnancy will be later diagnosed with brain disorders which can be related to attention or emotional problems. A number of studies have shown that during this critical time, exposure to music can help in stabilizing the heart rate and breathing of a premature baby. It can also improve sleeping and eating patterns.

Music is essentially sound form which is organised in time. A team of scientists in Switzerland have been testing the effects of music to protect the brain and they conducted a double-blind study on the musical effects in the neonatal ICU, whose initial results are quite promising. The study has been published in PNAS.

The premature babies who were born almost four months before their schedule were treated to a daily dose of music which was specially meant for them. Their brain functions showed better development than the ones who were not treated to music. Lara Lordier, a co-author in this study and a researcher at the University of Geneva and University Hospitals of Geneva said that the team arranged the various parts of the day with different types of music. A music to accompany when they wake up, one to interact with them while they are awake and also in their sleeping phase. The study was conducted on 24 full-term babies and 39 premature babies.

Out of 39 premature ones, 20 were treated to the musical intervention. They received approximately eight minutes of very soothing music consisting of bells, harps. The snake charmer’s flute of India was also played during the week five times, which incidentally had the maximum soothing effect on the babies.

With the help of functional MRI on all the three groups of infants, researchers found that neural networks of the children who were exposed to music had higher functional connectivity and the network resembled the full-term babies. The premature babies who listened to music had improved brain salience network and their auditory, sensory, thalamus networks were also improved. While those babies who were not treated to the music had poor functional connectivity.

It is crucial to take care of the babies’ brains in the intensive care unit in a proper strategic way since the brains are still immature. As the age of the participants reaches six, researchers will be able to test whether the cognitive benefits of the music have stuck with them through the years.

Brain computer interface schematic

Elon Musk announces updates on Neuralink to be declared soon

Elon Musk was asked for an update on Neuralink, the neuro-tech company he started in 2016, to which he replied with a tweet saying “Coming Soon.” Though started almost three years ago, there have not been any major announcements from the company. The company has been reported to developing implantable brain-computer interfaces(BCI) and is located at San Francisco, California.

Brain-computer interfaces provide a pathway for direct communication between an advanced brain and an external machine. Research on BCI first started in the 70s at the UCLA, after which it was offered a contract from DARPA. It primarily attempts to restore damaged hearing, eyesight and other motion activities with the help of advanced neuroprosthetics equipment. Neuroprosthetics such as cochlear implant have been widely used in people but they differ in some areas from BCI. While the neuroprosthetics make a connection of any part of the nervous system to a device, BCI attempts to connect the central nervous system( or brain) to a computer.

Neuralink primarily aims to manufacture devices which will help in treating severe brain diseases and brain damage that has been caused by a stroke. In the long run, it aims to make equipment for overall human enhancement.

The inspiration of this company came from a concept in science fiction named Neural Lace, which is in the fictional world created by author Iain M. Banks in his series of books The Culture. In the futuristic world of Culture, there are aliens, advanced beings, humanoids who live in places spread all over our galaxy, Milky Way.

Elon Musk has been quite vocal about the dangers which artificial intelligence pose to the human civilization and he has said that human beings have to augment their brains for survival in the coming times. According to Musk, if we do not develop we can be degraded to the position of servants in the world dominated by AI. So he feels that a solution can be adding an extra layer of AI to our brain.

Neuralink published a paper in 2015 describing a concept for the BCI. It explained the process of augmenting the human brain with a circuit. Charles Lieber, one of the co-authors of the paper from Harvard University mentioned how researchers are trying hard to minimize the differences that exist between electronic and neural circuits.

But the path is filled with dangers such as ethical mistakes, health side effects and scientists have warned that future advancements can result in manipulation of a person’s emotions, thoughts which is certainly not permissible.

brain cells analysis

For the first time, researchers restore cellular functions in brains of dead pigs

Scientists have been able to partially revive some of the functions in the brains of dead pigs, hours after they were killed in the slaughterhouse.

The team of researchers at the Yale University maintained that the brains did not regain the kind of electrical signals which are normally equated with being conscious. But they have been successful to preserve certain amount of cellular functions. The findings were reported in the Nature journal.

The research work has created confusion in the world of ethics, as it blurs the separation between the living being and the dead ones. Nita Farahany, faculty of ethics at Duke Law School said that she was quite astonished by the implications of the work as it changes a lot of the current understanding about neuroscience and the irreversible nature of loss of brain functioning due to oxygen deprivation.

It is known that the human brain is very sensitive to the lack of oxygen and it shuts off pretty quickly due to the absence of oxygen. But it is also known for a long time to the researchers that viable cells can be separated from the postmortem brain after its death. The main problem here is that it disturbs the 3D organisation and structure of the brain.

So scientists have been working on the technique to study about the brain cells in the organ itself, though they were not sure whether it would be successful or not. They named the technology as BrainEx, in which they did a fully detailed study on 32 pig heads.

The brains from the pigs’ heads were cleared out of the residual blood and the tissues were cooled down. Then they were placed in a chamber, where some vital blood vessels were tied to a device which pumped specially prepared chemicals for almost six hours.

The brains looked much different than the ones which were left to rot in the slaughterhouse Some of the molecular functions were restored and cell death was reduced. This has been described by scientists as a breakthrough achievement in brain study, as it converges the gap between neuroscience and clinical research.

But the researchers were worried about restoring consciousness in the brains. They constantly monitored the electrical activity in the brains and if they had seen any evidence of consciousness, they would have used anesthesia to cool it down.

The special solution used for testing in the brain cells consisted of an anti-seizure drug, lambotrigine which dampens the neuronal activity. Scientists are finding ways to tackle the ethical and legal issues related to the experiment and also on organ donation from the ones who have been declared brain dead.

brain organoids in a petri dish

Researchers created lab grown brain that independently connected to spinal cord

There are many diseases wherein one needs a donor to donate an organ, it is very difficult to get donors these days and even if you get one, it should be a perfect match. However, there are various complications that are bound to happen during the transplant. Hence, scientists are finding alternate solutions to transplant and that is nothing but growing an organ artificially and then letting it grow in the body.

It is very difficult to grow something in a laboratory as there are many factors that one has to consider, right from is it getting the proper environment to producing and also giving it the proper nutrition it requires.

After a lot of research, scientists in UK have cultivated an artificial brain in a dish and the behaviour of the brain is similar to the brain developed in humans. Scientists say that the size of the brain grown in the laboratory is similar to the size of human fetal brain at 12 to 13 weeks during which the ‘brain organoid is not complex since it doesn’t have any thoughts, feelings or consciousness – but that doesn’t make it entirely inert. It is composed of two million organized neurons.

The scientists when placed this piece of brain next to a piece of mouses’ spinal cord and a piece of mouses’ muscle tissue, this pea-sized blob of human brain cells sent out long, probing tendrils to check out its new neighbours. After which, they spontaneously connected itself to nearby spinal cord and tissue. This was observed with the help of long term live microscopy.

These probings aren’t the only skills. This brain was also the first sample to initiate muscle movement. The researchers also noticed the visible and controlled muscle contraction.

Lab Grown Brain

An image of the cerebral organoids grown from stem cells by Cambridge researchers.
Photograph: MRC Laboratory of Molecular Biology

Madeline Lancaster neuroscientist from the Medical Research Council Laboratory of Molecular Biology told The Guardian, “We like to think of them as mini-brains on the move.”

The authors mentioned, “After 2-3 weeks in co-culture, dense axon tracts could be seen innervating the mouse spinal cord and synapses were visible between human projecting axons and neurons of the mouse spinal cord. Live imaging of the mouse muscle tissue revealed sporadic concerted muscle contractions with irregular periodicity.”

Today, most brain organoids are grown from human stem cells, which spontaneously organize themselves into the structures and layers needed for early brain development. The problem is, once this cluster gets to a certain size, the middle becomes deprived of nutrients and oxygen and it stops becoming useful. Therefore the researchers sliced up the organoids and placed them on a porous membrane, the researchers made sure that their mini-brains could simultaneously use the air above and absorb the nutrients below, staying healthy after a year in their dishes.

The authors are hopeful that the success of their new approach will allow us to model brain diseases in greater detail than ever before.

The authors write, “For instance, it opens the door to the study of neurodevelopmental conditions of the corpus callosum, neuronal circuit imbalances seen in epilepsy, and other defects where connectivity is thought to play a role, such as in autism and schizophrenia.”

Published Research: https://www.nature.com/articles/s41593-019-0350-2

 

Pregnant Woman

Pregnancy infection may lead to autism and depression in kids

According to a recent study, there is an elevated risk for autism, depression and suicide in children, whose mothers were hospitalized during pregnancy due to infections.

Earlier research has indicated that infections caused by specific pathogens, such as cytomegalovirus and the herpes virus, can cause serious fetal brain injury, abnormal brain development and an even increased risk for certain psychiatric disorders.

The researchers studied the hospital records of nearly 1.8 million people, born in Sweden (1973 -2014), from birth to age 41. Those people whose mothers had been hospitalized for any infection during pregnancy had a 79% higher risk of being diagnosed with autism while a 24% increased risk of being diagnosed with depression. No increased risk was detected for two other disorders like psychosis, schizophrenia, and bipolar disorder.

The study was performed by researchers at the University of Washington School of Medicine in Seattle, Washington, and the Sahlgrenska Academy in Gothenburg, Sweden, co-led by Kristina Adams Waldorf, a professor of obstetrics and gynecology at the UW School of Medicine, and Verena Sengpiel, an associate professor in obstetrics and gynecology at Sahlgrenska Academy.

“It is unclear how an infection by a microbe that does not directly attack the fetal brain could nevertheless affect its development,” said lead author Benjamin al-Haddad, a pediatric resident at the UW School of Medicine.

“Research has shown that exposure to inflammatory proteins released by the mother’s immune system to fight off infection may affect gene expression in fetal brain cells.
Other research suggests that inflammation may increase the production of serotonin, a neurotransmitter, by the placenta, which may alter fetal brain development”, he added.

“Parts of the fetal brain are exquisitely vulnerable to damage from infection and inflammation, especially areas involving social and emotional function. I think we need to take a broader view of how infection and inflammation can harm the fetal brain, beyond the effects of direct infection of the brain, in the meantime, we should aggressively act to prevent and treat infections during pregnancy when we can”, Kristina Adams Waldorf said.

Waldorf said women should be more concerned about vaccines during pregnancy especially influenza vaccine because women are not only putting themselves at risk for serious and even fatal infections, but they may be putting their infants at risk for neuropsychiatric disorders later in life.

The researchers are hopeful that these findings would be fruitful for them for future research, would also make aware pregnant women to take the influenza vaccine to prevent their child from fatal diseases.

Published Researchhttps://ja.ma/2F3gqCu