First facial reconstruction of the Indonesian ‘Hobbit’ unveiled

Scientists at this week’s Australian Archaeological Conference have unveiled the face of Homo floresiensis— more commonly referred to as the ‘Hobbit’ — for the first time. Specialist facial anthropologist Dr. Susan Hayes used forensic facial approximation techniques to build out a female skull specimen discovered in 2003 in Flores, Indonesia. Other bones have been found since, revealing that these Hobbits were only about three and a half feet tall— just like the creatures of J.R.R. Tolkien lore that will hit the big screen later this week. Homo floresiensis populated the island of Flores between 95,000 and 17,000 years ago, but it’s not yet clear where the species falls within the human evolutionary tree. Although she’s pleased with the final results, Hayes says that the reconstruction was far from easy— “she’s not what you’d call pretty, but she is definitely distinctive.”

EyeWire launches today with J Day!

It’s time to mobilize a global community of citizen neuroscientists to trace the 3D structure of J Cells and understand how retinal connectomes relate to visual perception.

A specific type of retinal neurons called J Cells respond to stimuli that move downward on the retina (which is the same as upward in the visual world). Neuroscientists do not currently understand how the neural circuits of the retina cause the J Cell to respond in this way. That’s one of the reasons we built EyeWire. By playing EyeWire, you map the 3D structure of retinal neurons and their connections, and collaborate with neuroscientists at MIT, the Max Planck Institute for Medical Research, and Harvard.

Over the past several months, members of Sebastian Seung’s lab at MIT have been hard at work making sure EyeWire allows users to accurately contribute to research. During our beta period, an average of 30 to 50 people played EyeWire each day. Collectively, EyeWirers have mapped over 160,000 individual cubes since the beta went live in spring. We hope to dwarf these numbers in the coming months.

Check out a short video from Sebastian Seung, who shares why we created EyeWire and how you can get involved.

Mayo Clinic Researchers Uncover Toxic Interaction in Neurons that Leads to Dementia and ALS

Researchers at Mayo Clinic in Florida have uncovered a toxic cellular process by which a protein that maintains the health of neurons becomes deficient and can lead to dementia. The findings shed new light on the link between culprits implicated in two devastating neurological diseases: frontotemporal dementia and amyotrophic lateral sclerosis, also known as Lou Gehrig’s disease. The study is published Dec. 10 in the online issue of Proceedings of the National Academy of Sciences.

There is no cure for frontotemporal dementia, a disorder that affects personality, behavior and language and is second only to Alzheimer’s disease as the most common form of early-onset dementia. While much research is devoted to understanding the role of each defective protein in these diseases, the team at Mayo Clinic took a new approach to examine the interplay between TDP-43, a protein that regulates messenger ribonucleic acid (mRNA) — biological molecules that carry the information of genes and are used by cells to guide protein synthesis — and sortilin, which regulates the protein progranulin.

"We sought to investigate how TDP-43 regulates the levels of the protein progranulin, given that extreme progranulin levels at either end of the spectrum, too low or too high, can respectively lead to neurodegeneration or cancer," says the study’s lead investigator, Mercedes Prudencio, Ph.D., a neuroscientist at the Mayo Clinic campus in Florida.

The neuroscientists found that a lack of the protein TDP-43, long implicated in frontotemporal dementia and amyotrophic lateral sclerosis, leads to elevated levels of defective sortilin mRNA. The research team is the first to identify significantly elevated levels of the defective sortilin mRNA in autopsied human brain tissue of frontotemporal dementia/TDP cases, the most common subtype of the disease.

Infants process faces long before they recognize other objects

New research from psychology Research Professor Anthony Norcia and postdoctoral fellow Faraz Farzin, both of the Stanford Vision and NeuroDevelopment Lab, suggests a physical basis for infants’ ogling. At as early as four months, babies’ brains already process faces at nearly adult levels, even while other images are still being analyzed in lower levels of the visual system.

The results fit, Farzin pointed out, with the prominent role human faces play in a baby’s world.

"If anything’s going to develop earlier it’s going to be face recognition," she said.

The paper appeared in the online Journal of Vision.

The researchers noninvasively measured electrical activity generated in the infants’ brains with a net of sensors placed over the scalp – a sort of electroencephalographic skullcap.

The sensors were monitoring what are called steady state visual potentials – spikes in brain activity elicited by visual stimulation. By flashing photographs at infants and adults and measuring their brain activity at the same steady rhythm – a technique Norcia has pioneered for over three decades – the researchers were able to “ask” the participants’ brains what they perceived.

When the experiment is conducted on adults, faces and objects (like a telephone or an apple) light up similar areas of the temporal lobe – a region of the brain devoted to higher-level visual processing.

Infants’ neural responses to faces were similar to those of adults, showing activity over a part of the temporal lobe researchers think is devoted to face processing.

Can Going Hungry As a Child Slow Down Cognitive Decline in Later Years?

People who sometimes went hungry as children had slower cognitive decline once they were elderly than people who always had enough food to eat, according to a new study published in the December 11, 2012, print issue of Neurology®, the medical journal of the American Academy of Neurology.

“These results were unexpected because other studies have shown that people who experience adversity as children are more likely to have problems such as heart disease, mental illness and even lower cognitive functioning than people whose childhoods are free of adversity,” said study author Lisa L. Barnes, PhD, of Rush University Medical Center in Chicago.

For the African American participants, the 5.8 percent who reported that they went without enough food to eat sometimes, often or always were more likely to have a slower rate of cognitive decline, or decline that was reduced by about one-third, than those who rarely or never went without enough food to eat. The 8.4 percent of African American participants who reported that they were much thinner at age 12 than other kids their age also were more likely to have a slower rate of cognitive decline, also by one-third, than those who said they were about the same size or heavier than other kids their age. For Caucasians, there was no relationship between any of the childhood adversity factors and cognitive decline. Barnes said researchers aren’t sure why childhood hunger could have a possible protective effect on cognitive decline. One potential explanation for the finding could be found in research that has shown that calorie restriction can delay the onset of age-related changes in the body and increase the life span. Another explanation could be a selective survival effect. The older people in the study who experienced childhood adversity may be the hardiest and most resilient of their era; those with the most extreme adversity may have died before they reached old age.

Barnes noted that the results stayed the same after researchers adjusted for factors such as amount of education and health problems. The results also did not change after researchers repeated the analysis after excluding people with the lowest cognitive function at the beginning of the study to help rule out the possibility that people with mild, undiagnosed Alzheimer’s disease were included in the study.

Because relatively few Caucasians in the study reported childhood adversity, the study may not have been able to detect an effect of adversity on cognitive decline in Caucasians, Barnes said.

Postpartum women less stressed by threats unrelated to the baby

Following the birth of a child, new mothers may have an altered perception of stresses around them, showing less interest in threats unrelated to the baby. This change to the neuroendocrine circuitry could help the mothers adapt to the additional stress often accompanying newborns, say researchers from Indiana University’s Kinsey Institute and the University of Zurich.

When viewing disturbing images during the study, postpartum women reported less distress and demonstrated less activity in their amygdala, the part of the brain that controls emotional response, than nulliparous, or childless, women, according to functional magnetic resonance imaging.

When the childless women were administered a nasal spray containing the hormone oxytocin, however, their brain images looked more similar to the postpartum women, and they also reported less subjective stress when viewing the images.

"Our findings extend previous work showing a lower stress response with motherhood that likely enhances her ability to cope with this dramatic new role," said lead author Heather Rupp, director of psychology and neuroscience at Brain Surgery Worldwide Inc. and a research fellow at The Kinsey Institute for Research in Sex, Gender and Reproduction.

The study, “Amygdala response to negative images in postpartum verses nulliparous women and intranasal oxytocin,” was published in the online journal Social Cognitive and Affective Neuroscience.

Combination of imaging exams improves Alzheimer’s diagnosis

A combination of diagnostic tests, including imaging and cerebrospinal fluid biomarkers can improve prediction of conversion from mild cognitive impairment (MCI) to Alzheimer’s disease, according to a new study published online in the journal Radiology.

"Because new treatments are likely to be most effective at the earliest stages of Alzheimer’s disease, there is great urgency to develop sensitive markers that facilitate detection and monitoring of early brain changes in individuals at risk," said Jeffrey R. Petrella, M.D., associate professor of radiology, division of neuroradiology, and director of the Alzheimer’s Disease Research Lab at Duke University Medical Center (DUMC) in Durham, N.C. "Our study looks at whether more sophisticated diagnostic tests such as magnetic resonance imaging (MRI), positron emission tomography (PET) and spinal fluid protein analysis might provide additional prognostic information, compared to more readily available cognitive and blood testing."

According to the World Health Organization, more than 35 million people worldwide are living with Alzheimer’s disease, which is incurable, and the prevalence is expected to double by 2030.

"Although there is no cure for Alzheimer’s disease, there are four symptomatic treatments that might provide some benefits," said coauthor P. Murali Doraiswamy, M.D., professor of psychiatry at DUMC. "So developing the right combination of diagnostic tests is critical to make sure we enable an accurate and early diagnosis in patients, so they can evaluate their care options."

Anatomical Brain Images Alone Can Accurately Diagnose Chronic Neuropsychiatric Illnesses

Objective

Diagnoses using imaging-based measures alone offer the hope of improving the accuracy of clinical diagnosis, thereby reducing the costs associated with incorrect treatments. Previous attempts to use brain imaging for diagnosis, however, have had only limited success in diagnosing patients who are independent of the samples used to derive the diagnostic algorithms. We aimed to develop a classification algorithm that can accurately diagnose chronic, well-characterized neuropsychiatric illness in single individuals, given the availability of sufficiently precise delineations of brain regions across several neural systems in anatomical MR images of the brain.

Methods

We have developed an automated method to diagnose individuals as having one of various neuropsychiatric illnesses using only anatomical MRI scans. The method employs a semi-supervised learning algorithm that discovers natural groupings of brains based on the spatial patterns of variation in the morphology of the cerebral cortex and other brain regions. We used split-half and leave-one-out cross-validation analyses in large MRI datasets to assess the reproducibility and diagnostic accuracy of those groupings.

Results

In MRI datasets from persons with Attention-Deficit/Hyperactivity Disorder, Schizophrenia, Tourette Syndrome, Bipolar Disorder, or persons at high or low familial risk for Major Depressive Disorder, our method discriminated with high specificity and nearly perfect sensitivity the brains of persons who had one specific neuropsychiatric disorder from the brains of healthy participants and the brains of persons who had a different neuropsychiatric disorder.

Conclusions

Although the classification algorithm presupposes the availability of precisely delineated brain regions, our findings suggest that patterns of morphological variation across brain surfaces, extracted from MRI scans alone, can successfully diagnose the presence of chronic neuropsychiatric disorders. Extensions of these methods are likely to provide biomarkers that will aid in identifying biological subtypes of those disorders, predicting disease course, and individualizing treatments for a wide range of neuropsychiatric illnesses.

Trabecular meshwork cells from a pig’s eye

Image by Carmen Laethem (Aerie Pharmaceuticals Research Triangle Park, North Carolina, USA)

(Source: nikonsmallworld.com)