The medial temporal lobe (MTL) houses the human memory system. Broadly, it contains the hippocampus, parahippocampal cortex, perirhinal cortex, and entorhinal cortex.
"One big challenge in studying the MTL is its great anatomical variability across people. Therefore, prior studies that were using group-averaged data, blurred fine anatomical details between different subregions of the human MTL that are located in close proximity to each other. It is like studying face structure by averaging 1000 different faces together. We will get important organizational principles of a face – where the eyes and the nose are located, where the mouth is, but we will completely lose idiosyncratic important details," explains the study's first author, Daniel Reznik of MPI CBS.
According to him another challenge in studying the MTL in humans is that this brain region is strongly affected by susceptibility artifacts, therefore the ability to get good-quality signals from this brain region is highly limited. In the current study, the scientists solved these challenges in MTL imaging and finally explored the distributed cortical anatomy associated with different subregions of the human temporal lobe in individuals.
Daniel Reznik concludes and adds: "Similar cortical networks also exist in animals and perhaps the most exciting finding is that we have now evidence for potentially new cortical pathways in the human memory system compared with non-human primates."
Christian Doeller, Director of the Department of Psychology at MPI CBS, adds, "These new findings are important since even after many years of research into human memory, no one really knew how the regions in the MTL are connected with the rest of the human brain. Connectivity of the entorhinal cortex is of particular interest for us since this is one of the first brain regions affected by Alzheimer's disease. Our discovery defines the anatomical constraints within which human memory functions operate and are informative for studying the evolutionary development of temporal lobe circuitry in different species. For example, data from non-human primates show only slight connections between the entorhinal cortex and the frontal cortex in comparison – in contrast, we found that these connections are more pronounced in humans."
Daniel Reznik adds: "Since one of the networks connected to the human entorhinal cortex is also involved in social processing, we suspect that it is an evolutionarily young network that may have evolved after the extensive expansion of the cortex in humans."
Reference: "Dissociating distinct cortical networks associated with subregions of the human medial temporal lobe using precision neuroimaging" by Daniel Reznik, Robert Trampel, Nikolaus Weiskopf, Menno P. Witter and Christian F. Doeller, 29 June 2023, Neuron.
News
New book from NanoappsMedical Inc – Molecular Manufacturing: The Future of Nanomedicine
This book explores the revolutionary potential of atomically precise manufacturing technologies to transform global healthcare, as well as practically every other sector across society. This forward-thinking volume examines how envisaged Factory@Home systems might enable the cost-effective [...]
A Virus Designed in the Lab Could Help Defeat Antibiotic Resistance
Scientists can now design bacteria-killing viruses from DNA, opening a faster path to fighting superbugs. Bacteriophages have been used as treatments for bacterial infections for more than a century. Interest in these viruses is rising [...]
Sleep Deprivation Triggers a Strange Brain Cleanup
When you don’t sleep enough, your brain may clean itself at the exact moment you need it to think. Most people recognize the sensation. After a night of inadequate sleep, staying focused becomes harder [...]
Lab-grown corticospinal neurons offer new models for ALS and spinal injuries
Researchers have developed a way to grow a highly specialized subset of brain nerve cells that are involved in motor neuron disease and damaged in spinal injuries. Their study, published today in eLife as the final [...]
Urgent warning over deadly ‘brain swelling’ virus amid fears it could spread globally
Airports across Asia have been put on high alert after India confirmed two cases of the deadly Nipah virus in the state of West Bengal over the past month. Thailand, Nepal and Vietnam are among the [...]
This Vaccine Stops Bird Flu Before It Reaches the Lungs
A new nasal spray vaccine could stop bird flu at the door — blocking infection, reducing spread, and helping head off the next pandemic. Since first appearing in the United States in 2014, H5N1 [...]
These two viruses may become the next public health threats, scientists say
Two emerging pathogens with animal origins—influenza D virus and canine coronavirus—have so far been quietly flying under the radar, but researchers warn conditions are ripe for the viruses to spread more widely among humans. [...]
COVID-19 viral fragments shown to target and kill specific immune cells
COVID-19 viral fragments shown to target and kill specific immune cells in UCLA-led study Clues about extreme cases and omicron’s effects come from a cross-disciplinary international research team New research shows that after the [...]
Smaller Than a Grain of Salt: Engineers Create the World’s Tiniest Wireless Brain Implant
A salt-grain-sized neural implant can record and transmit brain activity wirelessly for extended periods. Researchers at Cornell University, working with collaborators, have created an extremely small neural implant that can sit on a grain of [...]
Scientists Develop a New Way To See Inside the Human Body Using 3D Color Imaging
A newly developed imaging method blends ultrasound and photoacoustics to capture both tissue structure and blood-vessel function in 3D. By blending two powerful imaging methods, researchers from Caltech and USC have developed a new way to [...]
Brain waves could help paralyzed patients move again
People with spinal cord injuries often lose the ability to move their arms or legs. In many cases, the nerves in the limbs remain healthy, and the brain continues to function normally. The loss of [...]
Scientists Discover a New “Cleanup Hub” Inside the Human Brain
A newly identified lymphatic drainage pathway along the middle meningeal artery reveals how the human brain clears waste. How does the brain clear away waste? This task is handled by the brain’s lymphatic drainage [...]
New Drug Slashes Dangerous Blood Fats by Nearly 40% in First Human Trial
Scientists have found a way to fine-tune a central fat-control pathway in the liver, reducing harmful blood triglycerides while preserving beneficial cholesterol functions. When we eat, the body turns surplus calories into molecules called [...]
A Simple Brain Scan May Help Restore Movement After Paralysis
A brain cap and smart algorithms may one day help paralyzed patients turn thought into movement—no surgery required. People with spinal cord injuries often experience partial or complete loss of movement in their arms [...]
Plant Discovery Could Transform How Medicines Are Made
Scientists have uncovered an unexpected way plants make powerful chemicals, revealing hidden biological connections that could transform how medicines are discovered and produced. Plants produce protective chemicals called alkaloids as part of their natural [...]
Scientists Develop IV Therapy That Repairs the Brain After Stroke
New nanomaterial passes the blood-brain barrier to reduce damaging inflammation after the most common form of stroke. When someone experiences a stroke, doctors must quickly restore blood flow to the brain to prevent death. [...]
