Life’s little pleasures often elude those suffering from depression, including rats, who show little interest in sugar water after experiencing stress. This behavior leads scientists to speculate that the illness might be characterized by a defect in the brain’s neural reward circuit.
Recent research focuses on a key element of this circuit – the nucleus accumbens (NAc), part of the brain region known as the ventral striatum, which is thought to regulate motivation and reward processing. In a new study of stress-induced depression in rats, researchers at the University of Minho in Braga, Portugal saw morphological changes in the dendrites of medium spiny neurons in the NAc, alongside disturbances in gene expression in this region. They also saw these changes reversed after administering antidepressants.
By using Neurolucida Explorer to analyze 3D reconstructions of medium spiny neurons generated with Neurolucida, the researchers observed longer than normal dendrites and greater spine density in the depressed rats. According to the paper, these findings contrast with studies of the hippocampus and prefrontal cortex, where chronic stress leads to shorter dendrites.
Continue reading “Scientists in Portugal Use Neurolucida Explorer to Analyze Neuroplasticity in Depression” »
Scientists hypothesize that seizures occur because brain cells fire in places they’re not supposed to. Dentate granule cells (DGCs), a type of neuron born throughout adulthood, sometimes migrate into a different region of the dentate gyrus, a part of the hippocampus. These abnormal newborn cells sprout axons called “mossy fibers” that form connections with neighboring DGCs in the inner molecular layer, causing synaptic changes that wouldn’t normally occur in healthy brains.
Much research has been done on this phenomenon, but neuroscientists still struggle to understand what exactly its relationship is with epilepsy.
A new study by researchers at the Cincinnati Children’s Hospital Medical Center validates hypotheses about the role of abnormal DGCs in epilepsy. In their study of a transgenic mouse model of temporal lobe epilepsy (TLE), the scientists observed a relationship between the presence of deviant DGCs and seizure frequency.
Continue reading “Cincinnati Scientists Use Neurolucida in Epilepsy Study” »
The placenta delivers nutrients from a mother’s blood to a developing fetus. It also produces hormones that help the baby grow during its forty or so weeks in utero. But the placenta’s powerhouse abilities don’t end there. The organ provides a wealth of information about the infant’s future health, allowing doctors to make predictions about whether or not the child will develop autism or, later in life, heart disease.
A recent study conducted at the Ludwig-Maximilians-University in Munich, Germany offers new insights into the relationship between the placenta and postnatal health.
Continue reading “Munich Scientists Analyze Placenta Morphometry with Stereo Investigator” »
If one area isn’t working, another part can step in. Plasticity is one of the brain’s most beautiful attributes. Recent research has documented the organ’s ability to compensate in the face of damage, and now a new study identifies a key region for compensation when the damage occurs in the hippocampus.
The region is the medial prefrontal cortex (mPFC). It’s an integral part of the hippocampal-prefrontal-amygdala circuit involved with memory formation – specifically with contextual fear memories. In their study, published last month in Proceedings of the National Academy of Sciences, researchers at the University of California, Los Angeles identify a microcircuit in the mPFC that can encode memories when the dorsal hippocampus is damaged.
Continue reading “UCLA Scientists Count Cells with Stereo Investigator in Study Identifying Compensating Regions in Brain Damage” »
Obstetricians and midwifes have long hailed the benefits of folic acid during pregnancy. Now new research offers evidence that choline is another important nutrient for the developing fetus. Found in foods like eggs and cauliflower, choline is known to aid healthy liver function. But in the past few years, studies have shown that the nutrient also plays a role in brain development. One recent study by Velasquez and colleagues claims that increased choline during pregnancy may offer a possible therapy for Down syndrome.
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According to scientists at the Hotchkiss Brain Institute in Calgary, Canada, there is evidence for increased neurogenesis in adult mice reared by two parents. Their study also describes other interesting findings, such as the fact that increased neurogenesis persists in the next generation, or that the effects of differences in rearing affect males and females differently.
Continue reading “Study Links Increased Touch to Enhanced Neurogenesis in Adult Mice; Stereo Investigator Used for Quantification” »
Researchers at the Waisman Center (University of Wisconsin-Madison) just took a big step in their quest to develop regenerative medicines for treating Parkinson’s, Alzheimer’s, and other neurodegenerative diseases. They used human embryonic stem cells to restore memory and learning in disabled mice.
The study, published last month in Nature Biotechnology, “is the first to show that human stem cells can successfully implant themselves in the brain and then heal neurological deficits,” senior author Su-Chun Zhang told the University of Wisconsin-Madison news department.
Continue reading “Wisconsin Scientists Use Stereo Investigator to Quantify Neurons Formed From Stem Cells” »
A baby makes eye contact with a passing stranger and his social development begins. Unable to resist the infant’s smile, the stranger smiles back and the baby starts to learn about human emotion through facial expression. But some babies, especially those on the autism spectrum, don’t make eye contact. What compels these tiny humans to avoid the eyes of people around them? Scientists specializing in developmental disabilities say the flocculus, a brain region in the cerebellum integral to eye movement control, may play a role in atypical gaze.
In their study of the postmortem brains of 12 autistic subjects and 10 control subjects, the research team, led by Dr. Jerzy Wegiel of the New York State Institute for Basic Research in Developmental Disabilities, in Staten Island, saw abnormally large flocculi in eight autistic subjects. According to the study, published last month in Brain Research, seven of these subjects exhibited “poor, very poor, or no eye contact” during the course of their lives.
Continue reading “Researchers Use Stereo Investigator to Identify Abnormalities in Autistic Brains” »
Learning a new dance routine or how to ride a bike is possible because of Cerebellar Granule Cells (GCs) according to Galliano and colleagues in The Netherlands. To find out more about the role of these abundant brain cells, and why we have so many of them, the scientists silenced most of the GCs in a group of mutant mice. They found the rodents could balance and run as well as they ever did, but when it came to learning new activities involving motor function, the mice had a harder time.
Continue reading “Neurolucida & Stereo Investigator Help Uncover Cerebellar Granule Cells’ Role in Muscle Memory” »
Spinal cord injuries can result in a range of physical disabilities from slight loss of motor function to major paralysis, but little is known about the mechanisms underlying the damage. Scientists affiliated with the Miami Project to Cure Paralysis at the University of Miami are gaining knowledge about how the nervous system responds to spinal cord injuries. Their latest study, published last month in the Journal of Neuroscience Research, suggests that post trauma cell death is associated with low zinc levels.
“The expression of functional NF-kB signaling resulted in a reduction in extracellular zinc levels, thereby inducing glutamate-induced cell death,” the authors say in their paper “Reduced Extracellular Zinc Levels Facilitate Glutamate-Mediated Oligodendrocyte Death After Trauma.”
Continue reading “Stereo Investigator Contributes to Study Showing Low Zinc Levels Associated With More Cell Deaths in Spinal Cord Injury” »