A central feature of theories of spatial navigation involves the representation of spatial relationships between objects in complex environments. The parietal cortex has long been linked to the processing of spatial visual information and recent evidence from single unit recording in rodents suggests a role for this region in encoding egocentric and world-centered frames. The rat parietal cortex can be subdivided into up to four distinct rostral-caudal and medial-lateral regions, which includes a zone previously characterized as secondary visual cortex. At present, very little is known regarding the relative connectivity of these parietal subdivisions. Thus, we set out to map the connectivity of the entire anterior-posterior and medial-lateral span of this region. To do this we used anterograde and retrograde tracers in conjunction with open source neuronal segmentation and tracer detection tools to generate whole brain connectivity maps of parietal inputs and outputs. Our present results show that inputs to the parietal cortex varied significantly along the medial-lateral, but not the rostral-caudal axis. Specifically, retrosplenial connectivity is greater medially, but connectivity with visual cortex, though generally sparse, is more significant laterally. Finally, based on connection density, the connectivity between parietal cortex and hippocampus is indirect and likely achieved largely via dysgranular retrosplenial cortex. Thus, similar to primates, the parietal cortex of rats exhibits a difference in connectivity along the medial-lateral axis, which may represent functionally distinct areas.
The U.S., Europe and Asia have launched big brain research projects. What impact will they have? Scientists integral to three projects share their insights ahead of a special session hosted by the Society for Neuroscience.
Researchers have shown how a single neuron can perform multiple functions in a model organism, illuminating for the first time this fundamental biological mechanism and shedding light on the human brain.
Despite great advances in understanding how the human brain works, psychiatric conditions, neurodegenerative disorders, and brain injuries are on the rise. Progress in the development of new diagnostic and treatment approaches appears to have stalled. Experts look at the challenges associated with 'translational neuroscience,' or efforts to bring advances in the lab to the patients who need them.
Donald J Bolger's insight:
Review of the issues with translational neuroscience.
Researchers have been tracking the traces of implicit and explicit memories of fear in human. The study describes how in a context of fear, our brain differently encodes contextual memory of a negative event (the place, what we saw ...) and emotional response associated.
'Our findings offer definitive answers regarding several scientific controversies about brain anatomy, which have occupied autism research for the past 10 to 15 years,' says one expert. 'Previous hypotheses suggesting that autism is associated with larger intra-cranial gray matter, white matter and amygdala volumes, or smaller cerebellar, corpus callosum and hippocampus volumes were mostly refuted by this new study.'
For the first time, robotic prostheses controlled via implanted neuromuscular interfaces have become a clinical reality. A novel osseointegrated (bone-anchored) implant system gives patients new opportunities in their daily life and professional activities.
Is it possible to rapidly increase (or decrease) the amount of information the brain can store? A new international study led by the Research Institute of the McGill University Health Centre (RI-MUHC) suggests is may be. Their research has identified a molecule that improves brain function and memory recall is improved. Published in the latest issue of Cell Reports, the study has implications for neurodevelopmental and neurodegenerative diseases, such as autism spectral disorders and Alzheimer’s disease.
“Our findings show that the brain has a key protein called FXR1P (Fragile X Related Protein 1) that limits the production of molecules necessary for memory formation,” says RI-MUHC neuroscientist Keith Murai, the study’s senior author and Associate Professor in the Department of Neurology and Neurosurgery at McGill University. “When this brake-protein is suppressed, the brain is able to store more information.”
Murai and his colleagues used a mouse model to study how changes in brain cell connections produce new memories. When FXR1P was selectively removed from certain parts of the brain, new molecules were produced. They strengthened connections between brain cells, which correlated with improved memory and recall in the mice.
“The role of FXR1P was a surprising result,” says Dr. Murai. “Previous to our work, no-one had identified a role for this regulator in the brain. Our findings have provided fundamental knowledge about how the brain processes information. We’ve identified a new pathway that directly regulates how information is handled and this could have relevance for understanding and treating brain diseases.”
“Future research in this area could be very interesting,” he adds. “If we can identify compounds that control the braking potential of FXR1P, we may be able to alter the amount of brain activity or plasticity. For example, in autism, one may want to decrease certain brain activity and in Alzheimer’s disease, we may want to enhance the activity. By manipulating FXR1P, we may eventually be able to adjust memory formation and retrieval, thus improving the quality of life of people suffering from brain diseases.”
The brain's plasticity and its adaptability to new situations do not function the way researchers previously thought, according to a new study. Earlier theories are based on laboratory animals, but now researchers have studied the human brain, and reached some new conclusions.
Being shown pictures of others being loved and cared for reduces the brain's response to threat, new research has found. The study discovered that when individuals are briefly presented pictures of others receiving emotional support and affection, the brain's threat monitor, the amygdala, subsequently does not respond to images showing threatening facial expressions or words. This occurred even if the person was not paying attention to the content of the first pictures.
Researchers have successfully replicated a direct brain-to-brain connection between pairs of people as part of a scientific study following the team's initial demonstration a year ago. In the newly published study, which involved six people, researchers were able to transmit the signals from one person's brain over the Internet and use these signals to control the hand motions of another person within a split second of sending that signal.
The way a person's brain responds to a single disgusting image is enough to reliably predict whether he or she identifies politically as liberal or conservative. As we approach Election Day, the researchers say that the findings come as a reminder of something we all know but probably don't always do: 'Think, don't just react.'
A new statistical test that looks at the patterns of high-frequency network activity flow from brain signals can help doctors pinpoint the exact location of seizures occurring in the brain and make surgery more effective, according to researchers.
It's one of those ideas that seems to make perfect sense: the bigger the brain, the more intelligent the creature. Exceptions are becoming increasingly common, yet the belief persists even among scientists. Most biologists, for example, assume that rats are smarter than mice. Scientists now challenge this belief. They compared mice and rats and found very similar levels of intelligence, a result that could have powerful implications for researchers studying complex behaviors and learning.