Endbrain

Basal ganglia (31)
Cerebral cortex (141)

Synopsis: Domenii: Neuroscience: Neuroscience generale: Nervous system: Central nervous system: Brain: Endbrain:

Animal studies show that both very low and very high levels of dopamine in the prefrontal cortex can impair working memory,

Parkinson disease is characterized by impairment or deterioration of neurons in an area of the brain known as the substantia nigra In the familial form of the disorder,

Researchers performed special brain scans of the visual cortex, which showed marked improvements in brain activities in patients who also improved in field size and acuity.

In a study with mice, his team found a previously unknown population of neurons within the subventricular zone (SVZ) neurogenic niche of the adult brain, adjacent to the striatum.

One such region may be the striatum which mediates motor and cognitive controls between the cortex

and the complex basal ganglia. he brain gives up prime real estate around the lateral ventricles for the SVZ niche housing these stem cells,

Studies of stroke injury in rodents have noted SVZ cells apparently migrating into the neighboring striatum.

And just last month in the journal Cell, a Swedish team observed newly made control neurons called interneurons in the human striatum for the first time.

as it is called, makes a protein that appears to regulate neurons in the cerebral cortex responsible for igher-orderfunctions, like information processing.

and Stroke (NINDS) part of the National institutes of health. t helps scientists study the dynamics of brain circuits that may explain the neural basis of learning. he researchers recorded neural activity in the subject s motor cortex

and simulating the cerebral cortex, the seat of cognition, ##Kurzweil continues;####The human cortex has about 22 billion neurons and 220 trillion synapses.##

For example the developing human brain contains genes that are more active in the frontal cortex than in the corresponding part of the mouse brain.

The frontal cortex is linked to personality and decision-making. Examples from the prenatal gene expression (left) and reference (right) atlases.

An implant recorded neural activity in the rat's motor cortex (the area that controls its movements), compared it to earlier recordings,

These pulses were delivered to the motor cortex of a second rat in the same lab#the decoder

the rod and cone cells that convert light into electrical signals transmitted via the optic nerve to the brain s visual cortex for processing.

The nerve impulses from these cells are led then via the optic nerve to the visual cortex where they create impressions of sight.

By studying over three thousand cells from the cerebral cortex in mice, one at a time and in detail, and comparing which of the 20,000 genes were active in each one,

such as that the pyramidal cells of the cerebral cortex are organised functionally in layers, says Jens Hjerling-Leffler,

to study the neurotransmitter dopamine in a region called the ventral striatum, which is involved in motivation,

This dopamine travels through the mesolimbic pathway to the ventral striatum, where it combines with sensory information from other parts of the brain to reinforce behavior

The researchers also developed an algorithm that lets them calculate the precise amount of dopamine present in each fraction of a cubic millimeter of the ventral striatum.

After delivering the MRI sensor to the ventral striatum of rats, Jasanoff team electrically stimulated the mesolimbic pathway

and was able to detect exactly where in the ventral striatum dopamine was released. An area known as the nucleus accumbens core, known to be one of the main targets of dopamine from the VTA,

showed the highest levels. The researchers also saw that some dopamine is released in neighboring regions such as the ventral pallidum,

the researchers produced a timeline of the brain object-recognition pathway that is very similar to results previously obtained by recording electrical signals in the visual cortex of monkeys,

visual information entered a part of the brain called the primary visual cortex, or V1, which recognizes basic elements of a shape,

The researchers believe the abnormal hyperactivity they found in the hippocampus may represent a disruption of the brain s default mode network a communication network that connects the hippocampus prefrontal cortex (where most thought

The electrodes communicated electrical activity from the brain's motor cortex via wires, to a prosthetic arm that the woman was able to move through a wide range of motions.

They implanted an electrode array in both his motor cortex and sensory cortex, the brain region that recognizes tactile sensations such as texture and pressure.

Wires from the motor cortex array controlled the hand, as they did for the female volunteer,

Currently electrode arrays in the motor cortex only work for a few years, although arrays in the sensory cortex appear to be more stable, he added d

"Researchers also sent wires from the man's motor cortex to the hand, so he was able to control its movements with his thoughts.

and is currently developing the game Brainflight to have as many as people as possible participating in a similar project for the cerebral cortex.

Due to the complex structure and the large number of connections in a piece of cerebral cortex

In addition, the team pla ced arrays on his motor cortex, the part of the brain that directs body movements.

Wires were run from he arrays on the motor cortex to a mechanical hand developed by the Applied Physics laboratory (APL.

"We found significant differences in the white matter tracts and abnormalities in brain circuits in the infants born early,

assistant professor of child psychiatry at Washington University School of medicine in St louis. White matter tracts in the brain are made of axons that connect brain regions to form networks.

#Stem Cell Research Hints at Evolution of Human brain The human cerebral cortex contains 16 billion neurons,

Now, researchers at UC San francisco have succeeded in mapping the genetic signature of a unique group of stem cells in the human brain that seem to generate most of the neurons in our massive cerebral cortex.

development and disease The discovery of human orgsself-renewing niche and remarkable generative capacity reinforces the idea that these cells may have been responsible for the expansion of the cerebral cortex in our primate ancestors,

migrate and hack into the brain blood supply appears to rely on a pattern of gene activity similar to that now identified in these neural stem cells. he cerebral cortex is so different in humans than in mice,

or in diseases of the cerebral cortex, this is a really exciting discovery. The study represents the first salvo of a larger BRAIN INITIATIVE-funded project in Kriegstein lab to understand the thousands of different cell types that occupy the developing human brain t the moment

which is a hub for signals passing between the hippocampus and the cerebral cortex. Tangles appear later in other nearby structures involved with memory and cognition,

it likely that the electrodes are stimulating the sections of motor cortex already associated with finger sensation.

Shimojo and postdoctoral scholar Noelle Stiles have exploited these crossmodal mappings to stimulate the visual cortex with auditory signals that encode information about the environment.

when your visual cortex is activated? But our research has shown that the visual cortex can be activated by sound,

indicating that we don really need our eyes to see. It very profoundee trying to give blind people a visual experience through other senses.

and motor cortex (the part that directs body movements) to the prosthesis. The mechanical hand that interfaces with the DARPA tech was developed by the Applied Physics laboratory at Johns hopkins university.

but most cortical areas go through a similar sequence of development. Therefore, different areas are all likely to go through the vulnerable period at some point in their development.

and the nucleus accumbens (associated with pleasure) work together in making critical decisions of this type,

However, following disruption of the circuit connecting the hippocampus and nucleus accumbens, the rats became impatient and unwilling to wait, even for a few seconds.

lesions to other parts of the brain, including the prefrontal cortex, known to be involved in certain aspects of decision-making,

and the nucleus accumbens is a ewardcenter and a major recipient of dopamine, a chemical responsible for transmitting signals related to pleasure and reward,

involving the hippocampus and nucleus accumbens, to be a therapeutic target in human patient groups. m

In vivo intracortical recordings from the rat motor cortex illustrate one mode of use for these ECM-NES l

The brain tissue here was mouse cerebral cortex. The rapid freezing method is able to prevent the water in the tissue from forming crystals,

the team placed arrays on the volunteer motor cortex, the part of the brain that directs body movements.

Wires were run from the arrays on the motor cortex to a mechanical hand developed by the Applied Physics laboratory (APL) at Johns hopkins university.

In some experiments, patients have been able to move prosthetic limbs just by thinking about it--a chip implanted in the brain translates the electricity in the brain motor cortex into instructions for the prosthetic to move.

In this experiment, the researchers used wires to connect a prosthetic arm to chip placed on the patient motor cortex, responsible for movement,

DARPA engineers and scientists at Johns hopkins university Applied Physics laboratory first inserted electrodes into the patient motor cortex.

Arrays were placed also on the volunteer motor cortex which is responsible for facilitating body movements.""The wires from the motor cortex allow the wearer to control the motion of the robot arm,

and pressure sensors in the arm that connect back into the sensory cortex give the wearer the sensation that they are touching something,

a faster degeneration of the temporal cortex, which is the region of the brain involved with memory;

"For example, with GIANT, researchers studying Parkinson's disease can search the substantia nigra network, which represents the brain region affected by Parkinson's,

The researchers have identified also a part of the prefrontal cortex--the large brain area located immediately behind the forehead that is associated with complex cognitive activities--that appears to evaluate such causal uncertainty

Based on the results, it appears that the ventrolateral prefrontal cortex (VLPFC) is involved in the processing and then couples with the hippocampus to switch on one-shot learning, as needed.

the researchers are intrigued by the fact that the VLPFC is very close to another part of the ventrolateral prefrontal cortex that they previously found to be involved in helping the brain to switch between two other forms of learning--habitual and goal-directed learning,

"Now we might cautiously speculate that a significant general function of the ventrolateral prefrontal cortex is to act as a leader,

However, following disruption of the circuit connecting the hippocampus and nucleus accumbens the rats became impatient and unwilling to wait, even for a few seconds.

Importantly, lesions to other parts of the brain, including the prefrontal cortex, known to be involved in certain aspects of decision-making,

and the nucleus accumbens is a"reward"center and a major recipient of dopamine, a chemical responsible for transmitting signals related to pleasure and reward,

involving the hippocampus and nucleus accumbens, to be a therapeutic target in human patient groups

#Missing piece surfaces in the puzzle of autism A study carried out by the Laboratoire Neurobiologie des Interactions Cellulaires et Neurophysiopathologie (CNRS/Aix-Marseille Université),

But only a"yes"answer generates a response intense enough to stimulate the visual cortex and cause the inquirer to see a flash of light known as a"phosphene."

identify structural damage between the thalamus and primary motor cortex as the obstacle between covert awareness and intentional movement.

and the motor cortex, which drives our voluntary muscular activity, as the reason behind the dissociation we have provided an important explanation."

the researchers assessed the integrity of the structural pathways that were revealed as essential for successful motor execution (those connecting the thalamus with the motor cortex.

in the motor cortex, for example, stimulating a particular spot causes motion in a specific part of the body.

said that deep brain stimulation brings multiple benefits. o negative effects have been reported in such prefrontal cortex stimulation in humans

By stimulating the front part of the brain known as the prefrontal cortex, new brain cells are formed in the hippocampus

our study shows a strong relationship between irregularities in speech-activation in the language-critical superior temporal cortex and actual,

#Scientists visualize critical part of basal ganglia pathways Breakthrough could help see pathways that degenerate with Parkinson and Huntingdon disease Certain diseases,

like Parkinson and Huntingdon disease, are associated with damage to the pathways between the brain basal ganglia regions.

The basal ganglia sits at the base of the brain and is responsible for, among other things, coordinating movement.

For the first time, Carnegie mellon University Brainhub scientists have used a noninvasive brain imaging tool to detect the pathways that connect the parts of the basal ganglia.

it is difficult to see the pathways within the basal ganglia with neuroimaging techniques, like the ever popular MRI,

the pathways that connect the basal ganglia regions are highly susceptible to damage. Because they are important for motor control,

In this study, the research team used two types of diffusion imaging to visualize the major pathways that connect the internal circuitry of the basal ganglia.

The researchers also found that by looking at the general patterns of water movement in the basal ganglia,

have shed light on this problem by discovering that some neurons in the cerebral cortex can adapt their properties in response to changes in network activity such as those observed during learning of a motor task.

whose primary role is regulating the activity of the principal cells of the cerebral cortex, known as pyramidal cells.

The cerebral cortex is outer layer of the brain and is associated with cognition, language and memory. ur findings explain the underlying mechanisms behind the dynamic regulation of the identity of interneurons said Nathalie Dehorter of the MRC CDN

says that nine months ago surgeons implanted two bunches of silicon electrodes, called Utah arrays, into the volunteer motor cortex.

Implants placed in contact with the brain motor cortex can gather far more detailed information however, including estimates of

Changes in blood flow in the prefrontal cortex can signal brain activity, allowing the program to read

They then used functional magnetic image resonance (fmri) imaging to show that a specific part of the brain (the medial wall of the precentral gyrus--a part of the primary motor cortex) activates both

While a handful of paralyzed people have used previously brain-computer interfaces (BCIS) to control robotic limbs, those subjectsimplants recorded signals from the primary motor cortex,

Sorto implant was the first to record instead from the posterior parietal cortex, a brain region involved in planning movements. human os iconlead researcher Richard Andersen, a neuroscience professor at Caltech,

the researchers first used functional magnetic resonance imaging to identify two precise regions of his parietal cortex that activated when he imagined reaching and grasping motions.

Most of the prior studies in which paralyzed people used implanted BCIS were conducted by John Donoghue, director of Brown University Institute for Brain science and a pioneer in the use of implants in the motor cortex.

Donoghue says that the new research advances our understanding of the parietal cortex role in generating movements

However, he not convinced it inherently a better signal than that provided by the motor cortex. ou get pretty good control from all these places

the ventromedial prefrontal cortex. he idea would be to decode a signal in the amygdala showing overactivity,

'The team looked at studies of the prefrontal cortex, an area of the brain that is crucial for working memory.

The electrodes are not in the motor cortex or attached to muscle nerves, but are in a part of the brain associated with planning muscle activity:

the posterior parietal cortex, or PPC. hen you move your arm, you really don think about which muscles to activate

and then shaking hands begins with a visual signal that is first processed in the lower visual areas of the cerebral cortex.

These intentions are transmitted to the motor cortex, on through the spinal cord, and then to the muscles where movement is executed.

Specifically, the findings reveal differences in the white matter of patientsbrains and in the cerebellum, an area of the brain not previously linked with the disorder.

the MRI signal was elevated in the cerebral white matter and the cerebellar region of patients affected by bipolar disorder.

and it calls for more comparative work to be done among cortical areas, Neske says. ou can just use one cortical region as the model for all inhibitory interneuron function.

The National institutes of health and the Defense Advanced Research Projects Agency supported the research, which was published in the Journal of Neuroscience e

Speech is produced in the human cerebral cortex. Brain waves associated with speech processes can be recorded directly with electrodes located on the surface of the cortex.

An electrode array was placed on the surface of the cerebral cortex (electrocorticography (ECOG)) for their neurological treatment.

The outer ortexof the organoid stratified into rudimentary layers, in a way eerily similar to how our own cerebral cortex matures.

and then repeatedly stimulate specific areas of the motor cortex in a noninvasive manner. The rtms device is a flat,

We hypothesize that pretreatment with carefully dosed magnetic pulses to the motor cortex will predispose participants to make bigger gains with therapy than they would have with 6 weeks of therapy alone.

Instead of targeting the motor cortex to promote recovery of arm movement, we can vary the location of magnetic stimulation to target the brain regions associated with other neurologic impairments, e g.,

Previous designs for mind-controlled prostheses linked the artificial limb to either the person's motor cortex or the individual's premotor cortex

This time, the connections to the robotic arm were wired into a patient's posterior parietal cortex,

"The posterior parietal cortex forms the initial plans to make movements, "said Richard Andersen, a professor of neuroscience at the California Institute of technology and one of the researchers who developed the new prosthesis.

the posterior parietal cortex outlines the steps in movement, then, the motor cortexes translate that plan into actual signals that are sent to specific parts of the arm.

The researchers used signals from the posterior parietal cortex"to extract the intent of the subject,

"Andersen told Live Science.""Instead of'I want to control muscles, 'we can use smart robotics to work out the fine details"of the movement a person wants to make.

the researchers explain how they connected the posterior parietal cortex of one patient, Erik G. Sorto,

to a computer that acted as a kind of artificial motor cortex. The computer used specific signals from the parietal cortex to detect what kind of movement Sorto intended to make,

and then translated that into signals for the robotic arm. Video: Tetraplegic Patient Controls Robotic Limb With His Brain In a video by the researchers, Sorto used the arm to serve himself a beer.

Sorto's ability to sip a brew came from the fact that the signals from the parietal cortex told the computer the general trajectory of the movement Sorto wanted to make,

posterior parietal cortex versus the premotor,"he said. Krishna Shenoy, a professor of electrical engineering who studies neural prostheses at Stanford,

"This is clearly the very first recordings from the posterior parietal cortex in humans in the context of qualifying the signals for use in prostheses,

They have focused on reading signals from the motor cortex, the part of the brain responsible for movement. The signals arising there,

That why researchers at Caltech decided to instead use signals coming from the posterior parietal cortex,

were implanted in the posterior parietal cortex. The researchers created software that processed and decoded the signals,

The investigators showed that sensing electric signals from the posterior parietal cortex can significantly improve the quality of the motion of robotic prostheses.

The next step the researchers are hoping to take is to gather data coming from both the motor cortex as well as the posterior parietal cortex

Here an example of the patient using the new robotic arm system controlled via the posterior parietal cortex:

Decoding motor imagery from the posterior parietal cortex of a tetraplegic humanource: Caltech S

#Boston Sci Precision Novi, World Smallest 16 Contact Spinal Stimulator OKD in EU (VIDEO) Boston Scientific is releasing in Europe the world smallest and thinnest 16

the motor cortex, can allow patients with paralysis to control the movement of a robotic limb.

Andersen and his colleagues wanted to improve the versatility of movement that a neuroprosthetic can offer to patients by recording signals from a different brain region other than the motor cortex, i e.,

, the posterior parietal cortex (PPC), a high-level cognitive area. In earlier animal studies, the Andersen lab found that it is here

These intentions are transmitted then to the motor cortex, through the spinal cord, and on to the arms and legs where the movement is executed. he PPC is earlier in the pathway,

Liu and his team implanted a pair of small electrode arrays in two parts of the posterior parietal cortex,

They identified a region in the supplementary motor cerebral cortex that is responsible for long-term musical memory an area that is involved in movement. ur study shows that the temporal lobes are not essential for musical memory,

People with similar injuries have controlled previously prosthetic limbs using implants placed in their motor cortex an area of the brain responsible for the mechanics of movement.

Richard Andersen at the California Institute of technology in Pasadena and his colleagues hoped they could achieve a more fluid movement by placing an implant in the posterior parietal cortex a part of the brain involved in planning motor movements."

Neuron control Andersen's team placed two implants measuring 4 millimetres squared into Sorto's posterior parietal cortex.

"The posterior parietal cortex is a fascinating area as it doesn't control the muscles so much as the plans you make to do something."

One unexplored possibility is that the posterior parietal cortex might also encode other kinds of intentions.

We have found for example one gene variant that affects the size of the Putamen a region near the centre of the brain

The Putamen is partly responsible for movement and learning and is implicated in Parkinson's disease. This finding opens up new avenues for research in this disease by giving new clues about the biological mechanisms involved.

Unless you know what'normal'development looks like it's hard to know how disease manifests in these sub-cortical regions.

Of the genetic associations found the largest effect was seen for the Putamen a subcortical region located at the base of the forebrain

In follow up protein expression work this variant was found to alter the expression of KTN1 in frontal cortex.

the Picower Professor of Neuroscience, showed that dramatic changes occur in the primary visual cortex when mice learn to distinguish novel from familiar visual stimuli.

Manipulations that prevented the changes in visual cortex also blocked memory formation. Impairments in detecting and recognizing familiar visual elements

synaptic transmission was changed in the primary visual cortex. Preventing or reversing this synaptic plasticity in visual cortex left the animals unable to distinguish familiar and novel visual stimuli.

Previously, the primary visual cortex was seen as a irst responderto visual stimuli that quickly passes information along to higher-order brain regions for interpretation

and memory storage. he study points to the visual cortex as a tool of learning and memory in its own right,

capable of storing simple but fundamentally important memories, Cooke says. ur work provides great hope for the future as it suggests we may have the chance to directly observe neurons undergo lasting changes as a very simple

contrary to the dogma that the primary visual cortex is relatively immutable in adults, a form of visual experience induces synaptic modifications in this area,

implanted in the brain movement center, the motor cortex, can allow patients with amputations or paralysis to control the movement of a robotic limb one that can be connected

recognizing someone you know) that is first processed in the lower visual areas of the cerebral cortex. The signal then moves up to a high-level cognitive area known as the posterior parietal cortex (PPC.

Here, the initial intent to make a movement is formed. These intentions are transmitted then to the motor cortex, through the spinal cord,

and on to the arms and legs where the movement is executed. High spinal cord injuries can cause quadriplegia in some patients

the motor cortex. The recorded signal is carried then via wire bundles from the patient brain to a computer,

However, because the motor cortex normally controls many muscles, the signals tend to be detailed and specific.

Our future studies will investigate ways to combine the detailed motor cortex signals with more cognitive PPC signals to take advantage of each area specializations. n the clinical trial,

in PPA, cortical areas degenerate, but their underlying fiber pathways, necessary for communication between different language centers in the brain,

Previously, scientists focused on the primary motor cortex, a part of the brain which coordinates the contractions muscles require to move

called the posterior parietal cortex. While the primary motor cortex focuses on specific muscle movements, the posterior parietal cortex is about planning movements.

Information from the implants in the posterior parietal cortex transmit the intent to pick up a pint of beer

and lets the computer figure out how to make the movement.""I wanted to run around and just high-five everybody.""

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