The brainThe brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. This part mentions brain circuits, cognition questions, brain injuries and brain tumours.
24/02/17 Giant neurons
Researchers at the Allen Institute for Brain Science used genetically modified mice to map certain neurons in the brain. Using the green fluorescent protein, they were able to build a 3D image of the branches of the neuron. One neurons wrapped itself entirely around the brain like a 'crown of thorns'.
10/11/16 Scientists map how the brain fights viruses
A new study in mice has discovered that one particular type of cell, called microglia, acts as “first responders to the scene” when the brain needs to defend itself.
It does so by coordinating the immune system's defence against the virus trying to infect the brain.
When microglia are not functioning optimally, it can lead to inflammation of the brain. And dysfunctional microglia may also be involved in diseases such as multiple sclerosis, depression, schizophrenia, and Alzheimer’s disease.
22/08/16 New technique turns mouse body transparent to study brain injury
A team of scientists from the Ludwig-Maximilians-Universität München in Germany has developed a technique (tissue clearing) that can turn an animal's body completely transparent. The technique works successfully on the whole bodies of mice and rats, allowing them to be studied to see how traumatic brain injuries affect the central nervous system.
18/04/16 Dissolving electrodes could ease pain of epilepsy surgery
Tested in rats - flexible electrodes have been created that dissolve harmlessly inside the brain after use. The US researchers that developed them believe that they could be used to pinpoint the source of epileptic seizures or monitor a patient's recovery after surgery before dissolving away, thereby removing the need for further surgery to extract the electrodes.
02/04/16 Nerve terminal nanofilaments control brain signalling
State-of-the-art electron microscopy reveals the large-scale organization of the proteins that regulate neurotransmitter release
03/03/16 Wireless brain electrode allow rhesus monkey to control robotic wheelchair by thought alone
Researchers have successfully implanted wireless electrodes into the brains of two rhesus monkeys allowing them to control a robotic wheelchair by thought alone. The experiments are the latest development in “brain-machine interfaces” (BMIs) technologies which offers hope to humans living with paralysis or motor neurone diseases such as ALS (also known as Lou Gehrig’s disease).
12/02/16 New brain-in-a-dish could help scientists model conditions in the human brain
The cells were created from the skin cells from five human adults which have been turned back into stem cells before being reprogrammed as brain cells. These cells can be monitored through electrodes and it is hoped it could reduce the number of animals used in drug testing.
05/02/16 Fixing memories
Tübingen neuroscientists have succeeded in activating dormant memory cells in rats. Using weak electrical impulses targeted at previously inactive cells in the hippocampus, the researchers induced the cells to recognize the exact place where the impulse had been first administered. In rodents as well as humans, the hippocampus is the brain area responsible for memory.
Maria Diamantaki, Markus Frey, Patricia Preston-Ferrer, Andrea Burgalossi: Priming Spatial Activity by Single-Cell Stimulation in the Dentate Gyrus of Freely-Moving Rats. Current Biology (in press). 4 February, 2016.
02/02/16 The functional diversity of retinal ganglion cells in the mouse
In the vertebrate visual system, all output of the retina is carried by retinal ganglion cells. Each type encodes distinct visual features in parallel for transmission to the brain. How many such ‘output channels’ exist and what each encodes are areas of intense debate. In the mouse, anatomical estimates range from 15 to 20 channels, and only a handful are functionally understood. By combining two-photon calcium imaging to obtain dense retinal recordings and unsupervised clustering of the resulting sample of more than 11,000 cells, here we show that the mouse retina harbours substantially more than 30 functional output channels. These include all known and several new ganglion cell types, as verified by genetic and anatomical criteria. Therefore, information channels from the mouse eye to the mouse brain are considerably more diverse than shown thus far by anatomical studies, suggesting an encoding strategy resembling that used in state-of-the-art artificial vision systems.
15/10/15 ‘Cuddle hormone’ makes marmosets more attractive to their long-term mates
A quick boost of oxytocin – also known as the ‘cuddle hormone’ or ‘love hormone’ – could help long-term relationships. Oxytocin is released naturally in the blood and brains of humans and other mammals during social and sexual behaviours. Previous research has shown that it enhances sociability through increased cooperation, altruism and communication. Researchers have now showed that marmosets that received oxytocin nose-drops attracted more social interaction from their long-term mates. The scientists observed gender differences - males that received oxytocin attracted more physical proximity from their female partners, while females treated with oxytocin attracted more grooming from their male partners.
15/10/15 New male specific ‘mystery’ neurons program to seek out sex over food
Scientists have discovered two extra neurons in the C. elegans nematode worm – thought to have had its entire nervous system mapped. These worms are the model animal of choice for many neuroscientists as their neural circuits are so simple that they can be mapped in full. These new neurons come as a surprise and are only found in male worms. They help males learn when to prioritize mating over eating. These cells give us a glimpse of how a seemingly simple brain can be capable of a complex learned behaviour. The scientists wish to understand next how these neurons contribute to circuits governing learning, and how they feed into sex differences in the brain.
05/09/15 Neurons responsible for alcoholism
Researchers have pinpointed a population of neurons in the brain that influences the numbers of drinks you order and could lead to a cure for alcoholism and other addictions. Alcohol consumption alters the structure and function of neurons in a part of the brain known to be important in goal-driven behaviours, according to a new study in animals.
13/08/15 growing neurons in the mouse brain
By turning on a single gene in specific neural cells in the embryonic mouse brain, researchers have made more neurons grow in the neocortex — a region that evolved to be much larger in primates than in other mammals.
07/08/15 Dogs process faces in a specialized brain area
Dogs process faces in a specialized brain area. The response to human faces in dogs is innate and not learnt. This is the first evidence for a face-selective region in the temporal cortex of dogs, only previously identified in humans and primates. Having a neural machinery dedicated to face-processing suggests that this ability is hard-wired through cognitive evolution and might explain why dog’s are so sensitive to human facial cues.
Dogs Process Faces in Specialized Brain Area
17/07/15 ‘speed cells’ in brain track how fast animals run
‘speed cells’ in brain track how fast animals run. The brain has its own system for tracking where we go and scientists have now discovered an extra component of this navigational system in rats – a group of neurons that alter their firing according to the pace at which the rodents run. This may explain how the brain maintains a constantly updated map of our surroundings.
10/07/15 Anxious or depressed brains are inherited shows study in rhesus monkey
Anxious or depressed brains are inherited shows study in rhesus monkey. Like shy children, young rhesus monkeys have an ‘anxious temperament’, whereby the monkey will stop moving and vocalizing in a stressful situation. Scientists found three brain regions associated with anxiety that could be inherited in monkeys, and that are supersensitive to normal threats. About 35% of the variation in early anxiety is explained by family history, which leaves room for the environment to shape the brain to be less anxious later on in life. Scientists are next looking at understanding the brain systems and molecular interactions that lead to hyperactive fear regions which could lead to a better understanding of mental disorders.
02/07/15 Memories are stored in the synapses in the hippocampus
Our memories are stored in brain connections called synapses that last as long as the memory they store. The hippocampus stores episodic memories – events that we might forget over time if not recalled. These memories are stored in mice for about a month to be then sent to the neocortex, where only some of the memories become permanent. Half of the spines on dendrites in the neocortex are long term repositories for memories while the others retain malleability for new memories of forgetting. Scientists found that the connections between the hippocampal neurone in live mice last for about 30 days – the duration of episodic memories in mice - whereas the spine turnover is 3 to 6 weeks. They concluded that the memories where stored in the synapses and not the spines of the hippocampal neurones.
29/06/15 Rats dream about the places they wish to go
Rats may dream of where they plan to go tomorrow, suggests new research from University College London. The rats were shown a food treat that they could see but not get to, and then were encouraged to sleep in a cosy nest while their brain activity was monitored. The neurons representing the route to the food in their brains fired as they sleep, suggesting that they were dreaming about running down the path to the treat.
23/06/15 Transparent zebra fish to track motor neurone disease in 'real time'
Transparent zebra fish allow researchers to track motor neurone disease in 'real time' as the disease develops. Dr Nicholas Cole, from the Macquarie University's Motor Neuron Disease Research Centre in Australia, inject zebra fish embryos with human genes that cause MND, along with several fluorescent jellyfish proteins that cause a yellow glow in dying neurons affected by the disease.
05/06/15 brain’s lymphatic vessels discovered – the brain is directly connected to the immune system by vessels previously thought not to exist
Study in mice shows that the brain is directly connected to the immune system by vessels previously thought not to exist. The vessels were detected after scientists developed a method to mount a mouse’s meninges – the membranes covering the brain – on a single slide so that they could be examined as a whole. The brain’s lymphatic vessels were so close to the blood vessels they had gone unseen until now. The unexpected presence of the lymphatic vessels raises a tremendous number of questions that now need answers, both about the workings of the brain and the diseases that plague it. It could have a huge impact on the study and treatment of neurological diseases ranging from autism to Alzheimer’s disease to multiple sclerosis.
Kevin Lee, who chairs the Department of Neuroscience, described the discovery : “The first time these guys showed me the basic result, I just said one sentence: ‘They’ll have to change the textbooks.’ There has never been a lymphatic system for the central nervous system, and it was very clear from that first singular observation – and they’ve done many studies since then to bolster the finding – that it will fundamentally change the way people look at the central nervous system’s relationship with the immune system.”
27/05/15 Fish are smarter than previously thought
Fish are proving themselves smarter than many scientists have given them credit for. In 1998 Bshary observed a grouper fish and a giant moray eel cooperating to hunt. Bshary created artificial reefs and found many the behaviours he spotted in the wild could be repeated in laboratory conditions.
27/05/15 Telomeres could provide useful targets for anti-cancer drugs
Studies in mice have suggested that telomeres, the caps at the end of each of our DNA strands, may provide a useful target for anti-cancer drugs. Since cancer cells require intact telomeres to replicate, researchers have tried blocking the growth of the protective covers at the ends of the telomeres (called shelterin). Studies in mice with an aggressive lung cancer showed that tumour growth could be prevented by using chemicals which block shelterin growth.
22/05/15 Bigger brains help female fish outwit predators and live longer
Bigger brains help female fish outwit predators and live longer. Bigger brains meant smarter guppies which meant they were more likely to outwit predators and live longer. However, this didn’t seem to work for males, whose bright colours may have countered any benefit of higher intelligence. The researchers did find that large-brained males were faster swimmers and better at learning and remembering the location of females. Size is a critical trait underlying cognitive ability but it is not the only trait, and there is enormous variation in brain size of vertebrates – both relatively and absolutely. Given that brains are energetically costly this means there is an optimal brain size that balances these costs and benefits.
05/05/15 The world’s biggest whales have nerves in their jaws that are very stretchy to help them feed
The world’s biggest whales have a biological secret weapon to help them feed: the nerves in their jaws are very stretchy. Roqual whales, a family that includes many of the large baleen whales such as blue and humpback, feed by engufing large volumes of water and krill. Researchers from the University of British Colombia examining the jaw of a fin whale discovered a stretchy cable that was found to be a nerve.
30/04/15 youthful binge drinking could lead to brain issues as you get older
New study in rats shows that youthful binge drinking could lead to brain issues as you get older. Drinking at early stages can cause memory problems in adults and brain cells may become more vulnerable to injury or disease.
08/04/15 Brain implant helps blind rats navigate
Scientists improved the navigational skills of blind rats by wiring them with a compass that sent electric signals to their brain when they were facing north or south. The advance helps shed light on how the brain processes sensory information and could lead to new technologies to help blind people navigate.
26/03/15 Nanorobotic agents open the blood-brain barrier, offering hope for new brain treatments
Nanorobotic agents open the blood-brain barrier, offering hope for new brain treatments. Magnetic nanoparticules tested in rodents can open the blood-brain barrier and deliver molecules directly to the brain, what 99% of therapeutic molecules are unable to do. The barrier is temporary opened at a desired location for approximately 2 hours by a small elevation of the temperature generated by the nanoparticles when exposed to a radio-frequency field. This could lead in breakthroughs in the treatment and diagnosis of brain disorders.
18/03/15 a virtual mouse maps out a mouse's brain in an atempt to reduce animal use
In an attempt to reduce animal research, scientists are looking to do tests on virtual mice instead. Over the last century, almost every medical breakthrough has been based on animal research. In an attempt to reduce the number of animals in research, the Human Brain project has taken the first step to building a virtual mouse for experiments. The digital model maps out how a mouse brain connects to a mouse body, using 200,000 virtual neurons. However, there is a long way to go before the model is an exact replica of the living mouse which has 75 million neurons, but as new data flows in, the researchers will continue to fill the model.
13/03/15 Cocaïne hijacks memory in rats
Cocaïne hijacks memory in rats. Researchers have found the cells linked to a mechanism in the brain that facilitates the role of memory in drug addiction. Memories associated with drug use are a leading suspect in driving the impulses behind drug addiction. Drug use creates memories so powerful they hijack the system, turning physiology into pathology. Pinpointing the neuronal pathway opens a new area of research for targeted therapy that would alter or disable the mechanism and make drug addiction less compulsive.
10/03/15 Scientists have created false memories in mice
Scientists have created false memories in sleeping mice by stimulating the part of the brain associated with specific places and the reward centre of the brain. Whenever the mouse thought about a specific location, and the place cells lit up, the reward centre of the brain was stimulated. When the mice woke up, they headed straight for the happy-associated location. It is thought this research could benefit PTSD patients.
03/03/15 the brain decision making structures were identified in rats
Is the decision-making part of the brain set out like an office? According to studies in rats, the striatum operates hierarchically - with three regions having distinct roles in motivation, adaptive decisions and routine actions. These parts work together, in an ordered manner.
25/01/15 Duck's highly sensitive bill could help understand the nervous system related to touch
Ducks could help researchers understand how the nervous system converts mechanical input from our fingers into electrical signals in our brain. The duck’s bill is highly sensitive to touch helping researchers to focus on the cellular workings of light touch sensations.
24/02/15 Oxytocin reverses the sedative effects of alcohol
Researchers at the University of Sydney have found that oxytocin appears to reverse the sedative effects of alcohol. They believe that the oxytocin binds to the parts of the brain’s GABA receptors which are affected by alcohol. It is hoped that such a drug could be used to treat alcohol disorders.
20/02/15 The gene that makes our brain bigger
Scientists have identified the gene that makes our brain bigger – and used it to make mice with super-brains. Mouse embryos developed massive, fast-growing brains after receiving the human gene in the womb, particularly in the region of the cerebral cortex – important region for decision making and thought in humans. Human DNA is 98% identical to Chimpanzees’ DNA, but we’ve got much bigger brains – a massive white matter growth occurs in the first two years of life with a super-fast proliferation of neuronal connections. Scientists have pinpointed the enhancer sequence responsible for this difference. They speculate that the gene is what separates our brains from those of other animals.
19/02/15 The science of munchies explained – cannabinoids hijack brain cells that normally supress appetite
The science of munchies explained – the urge to eat after smoking is caused by cannabinoids hijacking brain cells that normally supress appetite. Cannabis causes the brain to produce a different set of chemicals that transform the feeling of fullness into hunger. Scientists injected cannabinoids into the brains of mice and monitored which neurons were activated. This helped illuminate a previously unknown aspect of the brain’s feeding circuitry and could help design new drugsthat would boost or supress appetite at will.
03/02/15 Oxytocin improves social skills in autistic mice
Oxytocin improves skills in autistic mice. People and mice with autism spectrum disorders have difficulty with social behaviour and communication. A drug called risperidone helps with some of the symptoms of autism – repetitive behaviours – but so far nothing was successful at improving the ability to socialize. However, giving oxytocin to mice with autism-like symptoms restores their social behaviour, and administered early after birth, the effects where longer lasting – into adolescence and adulthood.
11/12/14 Mechanism in the brain that drives appetite for glucose specifically
Scientists have discovered a mechanism in the brain that may drive appetite for foods rich in glucose and could lead to treatments for obesity. Glucose is the main energy source used by the brain and by studying rats, researcher from Imperial College London have identified a mechanism that senses how much glucose is arriving to the brain and tells the animals to go look for some if needed. When food goes scarce, an enzyme, glucokinase - involved in sensing glucose in the liver and pancreas - becomes more active in an appetite-regulating centre in the hypothalamus which drives the rats to seek glucose out specifically among all food.
04/12/14 3D navigation cells in bats
Cells that enable bats to navigate through three dimensional space when flying have been identified in the brain. All mammals have cells in their brains that act as an inbuilt GPS – the 2014 Nobel Laureate John O’Keefe discovered the first component of this system in 1971 – but until now most spatial navigation work was conducted on rats running around on flat surfaces. Scientists at the Weismann Institute of Science in Israel recorded neuronal activity in the brain of fruit bats, identifying a cluster of cells that are responsible for encoding three dimensional space.
01/12/14 Mice with human brain cell with better cognition
The University of Rochester Medical Center in New York have injected human glial cells (the cells in the brain that support neurons) into mouse pups. Within a year the human cells had completely displaced the mouse cells.
The injected mice were found to have better memory and cognition across a battery of tests.
21/11/14 Converting structural cells into functioning neurons
Damaged areas in the brains of mice have been regenerated by converting structural cells into functioning neurons. No new neurons will grow in the cerebral cortex, the outer layer of brain tissue, so once these cells are damaged or die they are not replaced. By injecting mice with viruses carrying a short piece of genetic code, scientists from Ludwig-Maximillians University in Munich were able to encourage structural cells in the damaged brain regions to develop into neurons.
19/11/14 fear and addiction circuitry in transparent brain tissue
The neurons that fire in a mouse's brain in response to fear or addiction have been revealed by a technique that makes brain tissue completely transparent. The CLARITY technique involves infusing the brain tissue with acrylamide, which preserves the cell structure along with the DNA and proteins inside them. GM mice whose neurons were engineered to fluoresce were trained to expect either a fearful (electric shocks) or addictive (cocaine) experience when placed in a box. Once in the box, the mice had their fluorescing neurons activated, were killed, and their brains treated with CLARITY. An imaging system mapped all the fluorescing neurons and combined the images into a three dimensional brain model showing the pathways that lit up when the mice were afraid or anticipating cocaine.
22/10/14 Opening of the blood brain barrier
Scientists have managed to successfully open and close the protective cover around the brain – the blood-brain barrier – in a human patient as a means for drug delivery, following work in a range of animals including mice and monkeys. The blood-brain barrier, or ‘BBB’, is a sheath of cells that wraps around all the blood vessels in the brain, protecting is against pathogens but also preventing compounds like chemotherapy drugs from getting through. Since July a team from French medical start-up CarThera have been working with four glioblastoma patients, using a combination of ultrasound and an injection of microbubbles to open the BBB to allow the passage of chemotherapy drugs. It will still be a few months before they can determine the effect that their method is having on the tumours.
09/09/14 Xenon gas reduces brain damage
Xenon gas treatment after a head injury reduces the extent of brain damage according to research using mice. Mice were anaesthetised before a controlled mechanical force was applied to the brain. Mice treated with xenon gas shortly after injury performed better in tests of movement and balance, and also showed less damage to brain. Head injury is the leading cause of death and disability in people under the age of 45.