A recent study using ancient DNA extracted from fossilized bones of extinct American big cats has shed new light on their evolutionary history. The research reveals that the saber-toothed cats were a sister group to modern felines and diverged early on from their ancestors.
Researchers found that the brain uses signals from vestibular organs to make on-line adjustments to whole-body voluntary movements. This mechanism may be especially valuable in complex, high-precision movements such as gymnastics or circus performances.
Research by University of Bath scientists shows that DDT resistance confers an advantage when inherited through females, leading to its global spread. This discovery challenges the common assumption that genetic resistance always carries a fitness cost.
Fragile X syndrome is caused by a defect in the Fmr1 gene, which produces a nonfunctioning protein. Researchers found that mice lacking this gene only in specific neurons showed deficits in a motor learning task. The study also revealed abnormalities in signaling connections and dendrites of Purkinje cells in the cerebellum.
Researchers found that grasshopper auditory neurons respond optimally to specific stimulus ensembles that differ from natural sounds but overlap with components of mating calls. This challenges the efficient coding hypothesis and suggests a weighted ensemble of natural stimuli based on behavioral relevance.
A new study suggests that stem cells in bone marrow and blood can regenerate egg cells in adult mice, potentially leading to new fertility treatments and alternatives to hormone replacement therapy. The findings also provide evidence for the existence of germ cell progenitors outside of the ovary.
Researchers found evidence that specific variants of a bitter-taste receptor gene were strongly favored in early human evolution, leading to increased sensitivity to toxic compounds. This suggests a pivotal role for bitter-taste perception in toxin avoidance in humans.
Researchers tracked coral reef fish larvae using DNA paternity analysis and marking with tetracycline, finding that one third settled within a two-hectare area near their birth site. This study documents the smallest scale of dispersal for a marine fish species, providing insights into sustainable marine reserve management.
Researchers used a novel method to monitor brain activity during blinking, finding that brain areas responsible for visual input are temporarily suppressed. This neural mechanism may help prevent the brain from becoming aware of the eyelid sweeping down over the pupil during a blink.
Researchers used tendon vibration to induce bodily illusions, altering subjects' sense of touch and highlighting the brain's dynamic and flexible nature. The study sheds light on the constant updating of the internal map that interprets new perceptions.
Researchers found that cocaine disrupts normal connections between brain regions, leading to impulsive behaviors. The study used rats with cocaine sensitization, who showed impaired ability to change strategies in a maze.
Researchers created transgenic mice overproducing Ab40 and Ab42 to study their roles in AD pathology. The results showed that Ab42 mice accumulated extensive amyloid plaque and neural damage, while Ab40 mice showed little disease pathology. The study provides evidence for the critical role of Ab42 in initiating amyloid deposition.
A recent study has identified mitochondrial acyl-CoA:glycerol-sn-3-phosphate acyltransferase 1 (mtGPAT1) as a trigger for insulin resistance in the liver. The researchers found that mice lacking this enzyme were protected from fatty liver and liver insulin resistance, suggesting mtGPAT1 as a potential therapeutic target.
New study reveals that acute insulin pulses limit fat synthesis in the liver by activating a key molecule called CEACAM1. Regular periods of fasting between meals help maintain a healthy liver by allowing insulin levels to fluctuate.
Researchers found that tumor cells can stimulate blood vessel growth by activating the MAPK pathway and inducing Notch ligand Jagged1, which promotes formation of new vessels. This interplay between tumor cells and blood vessel cells supports tumor growth and progression.
Resistant tumor cells can be sensitized to ONYX-015 replication by inducing a heat shock response, which could greatly augment the therapy's clinical utility. This study suggests that clinical strategies focusing on tumor-selective replication would favor the use of ONYX-015.
Researchers found that genetically engineered flies with turned-off dopamine cells or those receiving dopamine inhibitors display converse behavioral effects to normal flies on methamphetamine. The study suggests dopamine plays a crucial role in modulating neuronal activity and assigning saliency to sensory stimuli.
Researchers found nearly equal proportions of two different sexes in a worldwide collection of 290 specimens, indicating recent evolutionary history of sexual activity. This discovery could lead to new strains with increased ability to cause disease and infect humans.
Researchers found that male mounting, even without semen transfer, reduces a hen's tendency to mate with other males and decreases the number of sperm obtained from a new rooster. This behavior helps defend paternity, suggesting copulations without semen transfer have evolutionary significance.
Newborn rats' brains show decreased NMDA receptor activity in olfactory-deprived side, leading to increased neuronal activation and saliency of early odors. This critical period affects olfactory development and learning.
A study published in Neuron found that the abnormal HD protein selectively binds to and increases the level of p53 in cells, leading to increased cell death and mitochondrial dysfunction. This overactivation also causes behavioral abnormalities in mice engineered to have HD.
Researchers found that bacterial infections trigger the production of antibodies against 'self' glycosphingolipids, leading to autoreactive T cell activation. This mechanism may contribute to the pathogenesis of autoimmune diseases such as multiple sclerosis and Guillain-Barré syndrome.
Researchers found that cells in the caudal region of the suprachiasmatic nuclei (SCN) synchronize their gene-expression rhythms to dawn, while those in the rostral SCN exhibit an opposite response. This suggests that synchronous gene expression may be a hallmark of short-day acclimation, while regional de-synchrony increases on long days.
Researchers found that brain predicts and attenuates internally-derived sensations to prioritize external stimuli. The study suggests an element of prediction is involved in attenuating internal sensations, making external touches more detectable.
Researchers have successfully cloned mice using direct nuclear transfer from terminally differentiated natural killer T cells. The cloned pups and their placentas exhibit rearranged T cell receptor genomic loci specific to NKT cells, demonstrating that fully differentiated cell nuclei can support embryo and placenta development.
Researchers found that bumblebees choose flowers based on the choices of other bees, especially when encountering unfamiliar plant species. This behavior suggests an efficient shortcut to success, and provides new insights into the complexity of insect foraging behavior.
Researchers found a correlation between delusion strength and 'world motion' perception in schizophrenia patients. This supports the view that delusions may be caused by an inability to attribute agency to sensory experiences.
Researchers investigated 24 mangrove sites in Sri Lanka and found that mangroves offered protection from tsunami waves, but pre-tsunami degradation had a profound impact on damage. The study highlights the urgent need for early warning systems for mangrove degradation to save human lives and property.
Researchers found that intrinsically photoreceptive retinal ganglion cells (ipRGCs) are present at birth and act as functional photoreceptors, providing input to the suprachiasmatic nucleus. This discovery has implications for the effect of light on early retinal development.
Researchers found that nicotine activates CREB in the brain's reward pathway, which is also triggered by opiates and cocaine. This suggests a potential new approach to treating nicotine addiction by blocking the reward pathway with opioid receptor blockers.
Researchers found that placebo treatment reduced subjects' ratings of unpleasant pictures and activity in emotional centers. The study generalizes the concept of placebo effect and its underlying neural mechanisms for both pain perception and emotional stimuli.
Researchers discovered that EGFR interacts with STAT3 in the cell nucleus, leading to increased expression of inducible nitric oxide synthase (iNOS) and a new transcriptional mechanism in human cancers. This interaction provides a potential target for anticancer therapies against EGFR, STAT3, and iNOS/NO.
Research reveals that mitochondrial activity produces reactive oxygen species that signal low oxygen levels, allowing cells to adapt and respond. Cells with disabled mitochondria fail to detect changes in oxygen availability, highlighting the critical role of mitochondria in oxygen sensing.
A study published in Cell Metabolism suggests that premature leptin surge in newborn mice of underfed mothers leads to remodeling of key brain circuits contributing to obesity later in life. The researchers found that the early leptin surge alone causes accelerated weight gain.
A new study reveals that pathogens play a significant role in shaping the evolution of human's most diverse genes, specifically those encoding Human Leukocyte Antigen (HLA) proteins. High HLA diversity is found to correlate with high pathogen diversity, particularly for certain types of HLA genes.
Researchers developed a drug cocktail combining morphine with methadone to prevent cellular signaling imbalances associated with opiate tolerance. The study found that rats receiving the cocktail experienced reduced morphine dependence, suggesting a potential approach for treating chronic pain.
Researchers found that trained meditative practice, particularly one-point meditation, can significantly alter the normal fluctuations in conscious state induced by perceptual rivalry. This suggests that high-level neural influences can modulate attention and consciousness, supporting previous work on the topic.
A new study found that a single gene, Fruitless, is responsible for controlling fly sexual behavior. The researchers discovered that female flies with the male version of the protein behave like males and engage in nearly identical courtship rituals.
Studies of brain-damaged patients reveal that remote autobiographical memories can be preserved even with limited damage to the medial temporal lobe. The researchers found that the ability to recall and experience these memories is more closely tied to neocortical areas than previously thought.
The study found that when subjects focus on one feature, they also attend to similar features elsewhere in the visual field. The researchers developed an experimental technique to measure this phenomenon and its implications for understanding how our brain processes visual information.
Researchers discovered that rat brains exhibit distinct responses to a six-hour delay in the light schedule, with one region adapting quickly and another taking several days. The study suggests that this difference in response is due to the neurotransmitter GABA, which affects brain regions differently.
Researchers found that birds, including domestic chicks and pigeons, show a leftward bias in pecking at grains, similar to human spatial hemineglect. This finding suggests that brain organization underlying attention asymmetries may offer benefits in spatial learning and tasks.
Researchers have identified the compound allicin as responsible for activating specific protein thermoreceptors in the mouth, leading to the characteristic burning sensation of raw garlic. This finding provides new insights into the pungency associated with raw garlic and its potential health benefits.
Scientists detect dopamine release from nucleus accumbens in rats, revealing three distinct signals associated with cocaine administration. The findings suggest that dopamine release transients are highly plastic and governed by motivation, learned association, and pharmacological actions.
Subjects rated odors more pleasant when labeled with positive words like 'cheddar cheese', whereas unpleasant labels had the opposite effect. The study also found that brain regions processing odors were activated by word labels, highlighting high-level cognitive inputs' impact on sensory perception.
Researchers discovered that HIV-1 induces RNA interference in human cells but has a strategy to combat this defense. The protein Tat suppresses RNA silencing, helping the virus evade the cell's natural immune response.
Researchers have identified MMP-7 as a key player in prostate cancer-driven bone destruction, revealing a potential therapeutic target for controlling cancer-induced bone loss. The study's findings suggest that MMP inhibitors may be effective in interrupting osteolysis and promoting bone growth.
A mouse model study reveals B cell activation is essential for early epithelial neoplastic development. Transfer of B cells restores chronic inflammation and tumorigenesis mechanisms, supporting the interaction between adaptive and innate immune systems in cancer development.
A new study published in Cell Metabolism found that normal metabolism requires so-called "new" fat to maintain glucose, lipid, and cholesterol homeostasis. The researchers discovered that old fat stores alone failed to set critical metabolic pathways in motion, leading to a marked decline in gene activity.
A new study reveals that mice with an excess of liver X receptor (LXRa) are protected from high-fat diet-induced cholesterol and blood vessel plaques. The findings suggest that natural variation in LXRa levels can influence susceptibility to heart disease, depending on diet.