What IS that? A photo by Stefan Kraft at Wikimedia Commons.1. Platypuses are so strange, that when British scientists first encountered one, they thought it was a joke: A Governor of New South Wales, Australia, sent a platypus pelt and sketch to British scientists in 1798. Even in their first published scientific description of the species, biologists thought that this duck-beaked, beaver-bodied, web-footed specimen may be some Frankenstein-like creation stitched together as a hoax. But this is only the beginning of their oddities…2. Platypuses are egg-laying mammals. Mammals are animals that have a backbone, are warm-blooded, and females produce milk for their young. Most females that nurse their young also carry their developing babies in their bodies and give birth to live young… But platypuses don’t play by those rules. Platypuses are monotremes, egg-laying mammals that include the platypus and four species of echidna. Most female mammals have two functional ovaries, but female platypuses, like most female birds, only have a functional left ovary. Once a year, a female platypus may produce a clutch of two or three small, leathery eggs (similar to reptile eggs), that develop in her uterus for 28 days. Because female platypuses don’t even have a vagina, when the eggs are ready, she lays them through her cloaca, an opening that serves for reproduction, peeing and pooping. (In fact, monotreme comes from the Greek for “one hole”). She then curls around them and incubates them for another 10 days until they hatch. 3. Platypuses sweat milk! Not only do female platypuses not have vaginas, they don’t have nipples either! Instead, lactating mothers ooze milk from pores in their skin, which pools in grooves on their bellies so the babies can lap it up. …And they’re not even embarrassed about it! 4. Adult platypuses are toothless. Baby platypuses (that is the actual technical term for them, by the way… not “puggles”, which would be way more fun) are born with teeth but they lose them around the time that they leave the breeding burrow. In their place are rigid-edged keratinized pads that they use as grinding plates. When they catch their prey (worms, bugs, shrimp, and even crayfish), they store it in their cheek pouches and carry it to the surface, where they use gravel to crush it in their toothless maw.5. The platypus “duck bill” is a sensory organ used to detect electric fields. Muscles and neurons use electrical impulses to function, and these impulses can be detected by electroreceptors. Although common in shark and ray species, electroreception is rare in mammals, only having been discovered in monotremes and the Guiana dolphin. Platypuses have rows of around 40,000 electroreceptors on their highly sensitive bill, which they wave back and forth in the water, much like a hammerhead shark, to determine the location of their prey. It’s a good thing this sense is so sensitive, since they close their eyes, nose and ears every time they dive. 6. Platypuses don’t use their tails like beavers do. Whereas beavers use their large, flat, leathery tails for swimming and slapping the water to send signals, platypuses don’t use their tails for any of that. Platypuses have large, flat tails for storing fat in case of a food shortage. Unlike beaver tails, platypus tails are covered in fur, which the mothers use to snuggle with their incubating eggs.A platypus ankle spur. Photo by E.Lonnon at Wikimedia Commons.7. Male platypuses have venomous ankle spurs. Their venom is strong enough to kill small animals and to create excruciating pain in humans. Since only males have it and they produce more venom during the breeding season, we think its main function may be to compete for mates and breeding territories.8. Platypuses are knuckle-walkers with a reptilian gait. Although they are well-built for swimming with their webbed feet and legs on the sides of their bodies, these traits make it quite awkward to get around on dry land. To walk, they pull in their webbing and walk on their knuckles, exposing their claws. Like reptiles and salamanders, platypuses flex their spines from side-to-side, supported by their sprawling legs. 9. Platypuses have unusually low body temperatures. As unusual as they are, platypuses are still mammals, which are defined, in part, by their ability to generate most of their own body heat with their metabolism. Platypuses do this as well, but whereas most mammals maintain body temperatures between 37-40 degrees C (99-104 degrees F), platypuses are happy with a body temperature of 32 degrees C (90 degrees F). This lower metabolism reduces the amount of calories they need to eat.10. They have no stomach. Stomachs are specialized protein-digesting chambers of digestive tracts that contain protein-digesting enzymes and acids to activate them. Not all animals have them, but most carnivores do. The most common exceptions to this rule are fish… and platypuses. Why? We don’t know for sure, but many of these animals consume diets high in calcium carbonate, which is a natural antacid. If their own diet would constantly neutralize their stomach acid, then the stomach really isn’t going to do them any good anyway.11. They have 10 sex chromosomes! Most mammals have two sex chromosomes, one from each parent. An individual that has two X chromosomes is usually female and an individual that has one X and one Y chromosome is usually male. Thus, female mammals pass along an X chromosome to each offspring and males can pass along an X or a Y. But platypuses are not content to be normal in any way…They have 10 sex chromosomes: 5 from mom and 5 from dad. All 5 chromosomes from mom are Xs, whereas a male sperm either contains 5 Xs or 5 Ys. Birds also have two sex chromosomes, but in birds, individuals with two of the same type are usually male and individuals with different chromosomes are usually female. Their system is called ZW, where the mammalian system is XY. The platypus X chromosome is more similar than the X chromosome of other mammals to the bird Z chromosome.12. The platypus genome is as much of a hodgepodge as its body. Only 80% of the platypus’ genes are like other mammals. Some of their genes have only previously been found in birds, reptiles, fish, or amphibians.To learn about more weird animals, go here.References: ... Read more »
Warren, W., Hillier, L., Marshall Graves, J., Birney, E., Ponting, C., Grützner, F., Belov, K., Miller, W., Clarke, L., Chinwalla, A.... (2008) Genome analysis of the platypus reveals unique signatures of evolution. Nature, 453(7192), 175-183. DOI: 10.1038/nature06936
The evolving epidemic of opioid overdose and overdose deaths is receiving increased public and research attention.Opioids overdoses and overdose deaths are often unintentional or accidental. It has been known that concurrent use of opioids with alcohol or benzodiazepines (i.e. Valium or Xanax) increases risk for overdose toxicity.A recent study published in the British Medical Journal confirmed the association of concurrent benzodiazepine prescription with opioid overdose.This research team examined confidential medical database records from over 500,000 patients in the U.S.Those that were enrolled in a medical plan including pharmaceutical benefits between 2001 and 2013 were included in the analysis.The key findings from the study included the following:The percentage of opioid users concurrently using a benzodiazepine rose from 9% of opioid users in 2001 to 17% of opioid users in 2013Chronic users of opioids nearly doubled their risk of opioid overdose if they took a concurrent benzodiazepine medication (4/100 persons/year to 7-8/100 person years)If the association is causal, the authors estimate emergency room visits and inpatient admissions could be reduced by 15% by stopping concurrent prescriptionsThis association of risk seems reasonable given the toxicities of opioids and benzodiazepines. Both at higher doses decrease respiratory drive potentially contributing to hypoxia and death.The authors note several take home messages for clinicians. Chronic users of benzodiazepines should be prescribed opioids cautiously if at all. Opioid prescriptions should be for short periods of time and low doses for chronic benzodiazepine patients.Likewise, if chronic opioids are necessary they should rarely be combined with intermittent or long-term benzodiazepine prescriptions.Readers with more interest in this topic can access the free full-text manuscript by clicking on the PMID link in the citation below.Photo of NCAA men's basketball tournament in Tulsa, OK is from my files.Follow me on Twitter WRY999Sun EC, Dixit A, Humphreys K, Darnall BD, Baker LC, & Mackey S (2017). Association between concurrent use of prescription opioids and benzodiazepines and overdose: retrospective analysis. BMJ (Clinical research ed.), 356 PMID: 28292769... Read more »
Sun EC, Dixit A, Humphreys K, Darnall BD, Baker LC, & Mackey S. (2017) Association between concurrent use of prescription opioids and benzodiazepines and overdose: retrospective analysis. BMJ (Clinical research ed.). PMID: 28292769
I just read a concerning paper about an experimental stem cell treatment for children with autism.
The authors are Himanshu Bansal and colleagues of India. The senior author, Prasad S Koka, is the Editor-in-Chief of the Journal of Stem Cells where the paper appeared, which raises questions about whether the manuscript received a thorough peer review. Koka is actually an author on all five of the research papers published in that issue of the journal. But that's a minor issue compared ... Read more »
Bansal H, Verma P, Agrawal A, Leon J, Sundell IB, Koka PS. (2016) A Short Study Report on Bone Marrow Aspirate Concentrate Cell Therapy in Ten South Asian Indian Patients with Autism. Journal of Stem Cells, 11(1). info:/
Emotional intelligence (EI) is characterized by the ability to recognize emotional states in self and in others.This emotional recognition may be helpful in guiding behavior and in improving interpersonal relationships.It seems logical on a face validity level to assume that higher levels of EI would be good in the selection of students for medical school.However, there are few studies assessing EI in physicians. There are fewer studies that examine whether EI influences physician behavior, patient satisfaction and ultimately patient outcomes.Rhamzan Shahid and colleagues at the Stritch School of Medicine at Loyola University Medical examined levels of EI in a group of resident physicians in training in the specialties of pediatrics and combined internal medicine-pediatrics.This was a cross-sectional study design that included comparison of residents in the first two years of training versus those in years 3 and 4. The main findings included the following:Residents tended to score high on EI overall with the highest scores on impulse control and the interpersonal composite subscaleResidents scored relatively lower on assertiveness and independence subscalesAssertiveness subscale scores were higher in the more senior residentsEmpathy scores were lower in the the more senior residentsIncreased assertiveness sub-scale scores in more senior residents might be a good thing, possibly indicating a growth in confidence and skill level. This cannot be stated definitely as this study was not longitudinally designed.The lower empathy sub-scale scores in senior residents is an interesting finding. Some might argue it is a negative consequence of training and reflects an increasing disenchantment with being a physician. The authors of the study encourage interventions to "ensure they (resident physicians) do not lose empathy".However, it may be that in a group selected for high empathy, a reduction may also represent a normal maturational process. Maybe high empathy contributes to higher physician distress in the clinical setting and potentially more burnout and depression. Maybe empathy levels that are too high produce emotional states that actually impair physician behavior and reduce effectiveness of clinical decision making.These possibilities should prompt studies correlating EI with patient satisfaction, patient outcome, physician satisfaction with medicine and their specialty and risk for physician burnout.The manuscript reviewed and commented on today is available in free full-text format by clicking on the link in the citation below.Follow me on Twitter @WRY999Photo of the lesser scaup duck is from my personal photography files.Shahid, R., Stirling, J., & Adams, W. (2016). Assessment of Emotional Intelligence in Pediatric and Med-Peds Residents Journal of Contemporary Medical Education, 4 (4) DOI: 10.5455/jcme.20170116015415... Read more »
Shahid, R., Stirling, J., & Adams, W. (2016) Assessment of Emotional Intelligence in Pediatric and Med-Peds Residents. Journal of Contemporary Medical Education, 4(4), 153. DOI: 10.5455/jcme.20170116015415
How much damage can the brain take and still function normally? In a new paper, A Lesion-Proof Brain?, Argentinian researchers Adolfo M. García et al. describe the striking case of a woman who shows no apparent deficits despite widespread brain damage.
The patient, "CG", is 44 years old and was previously healthy until a series of strokes lesioned large parts of her brain, as shown below.
García et al. say that the damage included "extensive compromise of the right fronto-temporo-parie... Read more »
García, A., Sedeño, L., Herrera Murcia, E., Couto, B., & Ibáñez, A. (2017) A Lesion-Proof Brain? Multidimensional Sensorimotor, Cognitive, and Socio-Affective Preservation Despite Extensive Damage in a Stroke Patient. Frontiers in Aging Neuroscience. DOI: 10.3389/fnagi.2016.00335
Amyloid brain plaques are well-known pathological changes associated with Alzheimer's disease. Changes preceding amyloid plaque build up are less well studied and understood. Some of this relates to limitations to current imaging technology.Klementieva and colleagues from Sweden and Spain recently published an important reserach topic in this area.Their studied used a rat model of Alzheimer's disease and imaging techniques that included infrared microspectroscopy and gel electrophoresis.The main findings of their study included the following:Conformation changes of beta amyloid and it's amyloid precursor protein (APP) start before the development of amyloid plaquesThe early changes in beta amyloid localize to the synaptic terminalsThese early changes may provide novel targets for drug developmentThese findings suggest current strategies to alter beta amyloid plaques after development may be too late to alter the course of the disease.Identification and reversal of earlier mechanisms may be a more productive drug development strategy.Readers with more interest in this topic can access the free full-text manuscript by clicking on the citation link below.Follow be on Twitter WRY999Photo of robin in back yard waterer is from my photography files.Klementieva, O., Willén, K., Martinsson, I., Israelsson, B., Engdahl, A., Cladera, J., Uvdal, P., & Gouras, G. (2017). Pre-plaque conformational changes in Alzheimer’s disease-linked Aβ and APP Nature Communications, 8 DOI: 10.1038/ncomms14726... Read more »
Klementieva, O., Willén, K., Martinsson, I., Israelsson, B., Engdahl, A., Cladera, J., Uvdal, P., & Gouras, G. (2017) Pre-plaque conformational changes in Alzheimer’s disease-linked Aβ and APP. Nature Communications, 14726. DOI: 10.1038/ncomms14726
Older drivers are over-represented in motor-vehicle driving accidents.The lowest rate of fatal vehicle crashes per 100 million miles driven is found in drivers between the ages of 30-69 years of age.Fatal vehicle driving rates per miles driven is 4 to 5 times higher in drivers over 80 years of age. (IIHS.org data)So can older drivers be trained or educated to improve their safety (and the safety o those around them)?A recent randomized controlled trial examined an educational intervention in drivers 75 years and older in Australia.This intervention targeted a reduction or avoidance of seven high-risk driving situations:Night drivingDriving in the rainRight-hand (left-hand in U.S.) turns across oncoming trafficDriving during heavy trafficDriving on high-speed roadsDriving during rush hourDriving aloneThe trial found participants in the intervention group showed a greater readiness to make changes that could reduce high-risk accident exposure. However, the intervention group did not reduce total miles driven in the year following the intervention.Additionally, the intervention group did not increase their use of alternate transportation (i.e. buses or cabs) in the follow-up period.This trial showed limited response to educational training in an older-aged drivers population. Alternate approaches (adoption of high safety feature vehicles, use of newer alternative driving programs like Uber, cognitive training programs to improve psychomotor speed) may hold more promise in reducing fatal accident rates in elderly populations.Follow me on Twitter WRY999Photo of moon is from my photography files.Coxon K, Chevalier A, Brown J, Clarke E, Billot L, Boufous S, Ivers R, & Keay L (2016). Effects of a Safe Transportation Educational Program for Older Drivers on Driving Exposure and Community Participation: A Randomized Controlled Trial. Journal of the American Geriatrics Society PMID: 27943260... Read more »
Coxon K, Chevalier A, Brown J, Clarke E, Billot L, Boufous S, Ivers R, & Keay L. (2016) Effects of a Safe Transportation Educational Program for Older Drivers on Driving Exposure and Community Participation: A Randomized Controlled Trial. Journal of the American Geriatrics Society. PMID: 27943260
Fig 1 (Roskams-Edriset al., 2017). The number of patents implicating specific brain regions has risen from 1976 to the mid 2010s. Results were obtained by searching The Lens patent database (http://lens.org/).
“What is the ethical value of awarding patent rights that implicate regions of the brain?”
Do the applicants intend to patent the function of specific brain areas? This absurd
... Read more »
Roskams-Edris, D., Anderson-Redick, S., Kiss, Z., & Illes, J. (2017) Situating brain regions among patent rights and moral risks. Nature Biotechnology, 35(2), 119-121. DOI: 10.1038/nbt.3782
Imagine there is a cookie sitting in front of you. You are hungry. You have been on a diet for months. If you have to look at one more raw, paleo, gluten free snack you are going to scream.... Read more »
Lehne, M., & Koelsch, S. (2015) Toward a general psychological model of tension and suspense. Frontiers in Psychology. DOI: 10.3389/fpsyg.2015.00079
Naqvi, N., Gaznick, N., Tranel, D., & Bechara, A. (2014) The insula: A critical neural substrate for craving and drug seeking under conflict and risk. Annals of the New York Academy of Sciences, 53-70. PMID: 24690001
Saarikallio, S., Nieminen, S., & Brattico, E. (2012) Affective reactions to musical stimuli reflect emotional use of music in everyday life. Musicae Scientiae, 17(1), 27-39. DOI: 10.1177/1029864912462381
What happens in the brain when we die?
Canadian researchers Loretta Norton and colleagues of the University of Western Ontario examine this grave question in a new paper: Electroencephalographic Recordings During Withdrawal of Life-Sustaining Therapy Until 30 Minutes After Declaration of Death
Norton et al. examined frontal EEG recordings from four critically ill patients at the point where their life support was withdrawn. Here are some details on the four:
Here's the EEG recor... Read more »
Norton L, Gibson RM, Gofton T, Benson C, Dhanani S, Shemie SD, Hornby L, Ward R, & Young GB. (2017) Electroencephalographic Recordings During Withdrawal of Life-Sustaining Therapy Until 30 Minutes After Declaration of Death. The Canadian Journal of Neurological Sciences, 44(2), 139-145. PMID: 28231862
There are significant barriers to widespread use of hearing-aids in older adults with age-related hearing loss.Sensitivity to the stigma of wearing a hearing-aid is one barrier.Cost is another significant barrier. In the U.S., bilateral hearing-aid purchase amounts to a cost of $2400 to $5800. This cost is typically not covered by Medicare or other health insurance plans.I ran into a interesting manuscript on looking at an alternative less costlier approach to hearing-aid selection and purchase.Larry Humes and colleagues compared the outcome of a older adults randomized to one of three hearing aid interventions. One was standard audiology best practices, one was a placebo hearing-aid (device without amplication). A third alternative was also studied that was called an over-the-counter (OTC) intervention. This intervention included the following elements:Self-selection of hearing aid tips, tubes and devicesThree types of hearing-aids were provided for selection. Each was programmed with one of the three most common patterns of hearing lossSubjects tried various combinations of devices and listened to sample sounds of speech, music and environmental soundsSubjects were assessed after a six week trial for hearing function, satisfaction and desire to keep the deviceSubjects were randomized to pay a fee of $3500 versus $600 for devices that were identical in features. This allowed for study of the effect of cost on outcome measures.Interestingly, the OTC intervention resulted in outcomes (i.e. hearing improvement) that were very similar to audiology best practices. However, OTC subjects showed a slightly lower satisfaction score and were somewhat more likely to return devices after the study for a refund. Higher price also predicted return for refund following the study.The authors conclude:"Efficacious OTC service-delivery models (and devices) may increase accessibility and affordability of hearing aids for millions of older adults, but further research is required to evaluate various devices and approaches as well as to examine the generalization of the findings from this clinical trial."This study provides an impetus for further study of the OTC model in hearing aid selection and use. Cost issues appear to continue to be a significant barrier to wider hearing-aid access.Readers with more interest in this study can access the free full-text manuscript by clicking on the link in the citation below.Photo of wood duck is from my photography file.Follow me on Twitter WRY999Humes, L., Rogers, S., Quigley, T., Main, A., Kinney, D., & Herring, C. (2017). The Effects of Service-Delivery Model and Purchase Price on Hearing-Aid Outcomes in Older Adults: A Randomized Double-Blind Placebo-Controlled Clinical Trial American Journal of Audiology DOI: 10.1044/2017_AJA-16-0111... Read more »
Humes, L., Rogers, S., Quigley, T., Main, A., Kinney, D., & Herring, C. (2017) The Effects of Service-Delivery Model and Purchase Price on Hearing-Aid Outcomes in Older Adults: A Randomized Double-Blind Placebo-Controlled Clinical Trial. American Journal of Audiology, 1. DOI: 10.1044/2017_AJA-16-0111
Neurofeedback training (NFT) is a procedure that tries to shape a participant's pattern of brain activity by providing real-time feedback, often in the form of a video game combined with other sensory stimuli that provide rewards when the “correct” state is achieved. The most common form of NFT uses EEG (brainwave) activity recorded non-invasively from the scalp. The EEG is a complex mixture
... Read more »
Manuel Schabus, Hermann Griessenberger, Maria-Teresa Gnjezda, Dominik P.J. Heib, Malgorzata Wislowska, Kerstin Hoedlmoser. (2017) Better than sham? A double-blind placebo-controlled neurofeedback study in primary insomnia. Brain. info:/10.1093/brain/awx011
Sitaram, R., Ros, T., Stoeckel, L., Haller, S., Scharnowski, F., Lewis-Peacock, J., Weiskopf, N., Blefari, M., Rana, M., Oblak, E.... (2016) Closed-loop brain training: the science of neurofeedback. Nature Reviews Neuroscience, 18(2), 86-100. DOI: 10.1038/nrn.2016.164
Despite centuries of experience in education, the best time to start formal education is still under debate. Is five years of age too old? Is three years of age too early?One issue with early education interventions is the potential for catch-up in children starting school later. In other words, early gains with younger children may evaporate overtime.One recent research study examines effectiveness of a child development intervention known as Educare. Educare seeks to reduce the achievement gap between low-income and economically advantaged peer children.Educare is operational in 21 cities in the United States. It is somewhat unique in entering children as infants (<1 year of age) for an intensive ongoing child and parent intervention. A recent study randomized 239 infants to receive Educare or no intervention. This study found superiority for the Educare children following one-year of intervention in the following domains:Expressive communicationAuditory comprehensionProblem behaviors (reduced level)Positive parental-child interactionThe authors note the size of the effects were in the modest to medium strength. Additionally, they note they cannot know how enduring the effects of this type of intervention might be.Additional longitudinal assessments will be needed to examine the potential of catch up in the control group. Studies of elementary, middle and senior high achievement will be needed.Aggressive early intervention programs are expensive and will need to be validated before efforts to expand this type of early childhood intervention.Follow me on Twitter WRY999Photo of children playing on the beach at sunset is from my photography files.Yazejian, N., Bryant, D., Hans, S., Horm, D., St. Clair, L., File, N., & Burchinal, M. (2017). Child and Parenting Outcomes After 1 Year of Educare Child Development DOI: 10.1111/cdev.12688... Read more »
Yazejian, N., Bryant, D., Hans, S., Horm, D., St. Clair, L., File, N., & Burchinal, M. (2017) Child and Parenting Outcomes After 1 Year of Educare. Child Development. DOI: 10.1111/cdev.12688
Where are the mammillary bodies?
The mammillary bodies are part of the diencephalon, which is a collection of structures found between the brainstem and cerebrum. The diencephalon includes the hypothalamus, and the mammillary bodies are found on the inferior surface of the hypothalamus (the side of the hypothalamus that is closer to the brainstem). The mammillary bodies are a paired structure, meaning there are two mammillary bodies---one on either side of the midline of the brain. They get their name because they were thought by early anatomists to have a breast-like shape. The mammillary bodies themselves are sometimes each divided into two nuclei, the lateral and medial mammillary nuclei. The medial mammillary nucleus is the much larger of the two, and is often subdivided into several subregions. What are the mammillary bodies and what do they do?The mammillary bodies are best known for their role in memory, although in the last couple of decades the mammillary bodies have started to be recognized as being involved in other functions like maintaining a sense of direction. The role of the mammillary bodies in memory has been acknowledged since the late 1800s, when mammillary body atrophy was observed in Korsakov's syndrome---a disorder characterized by amnesia and usually linked to a thiamine deficiency. Since then a number of findings---anatomical, clinical, and experimental---have supported and expanded upon a mnemonic role for the mammillary bodies.The mammillary bodies are directly connected to three other brain regions: the hippocampus via the fornix, thalamus (primarily the anterior thalamic nuclei) via the mammillothalamic tract, and the tegmental nuclei of the midbrain via the mammillary peduncle and mammillotegmental tract. Two of the three connections are thought to primarily carry information in one direction: the hippocampal connections carry information from the hippocampus to the mammillary bodies and the thalamic connections carry information from the mammillary bodies to the thalamus (the tegmental connections are reciprocal). These connections earned the mammillary bodies the reputation of being relay nuclei that pass information from the hippocampus on to the anterior thalamic nuclei to aid in memory consolidation. This hypothesis is supported by the fact that damage to pathways that connect the mammillary bodies to the hippocampus or thalamus is associated with deficits in consolidating new memories. Others argue, however, that the mammillary bodies act as more than a simple relay, making independent contributions to memory consolidation. Both perspectives emphasize a role for the mammillary bodies in memory but differ as to the specifics of that role.Further supporting a role for the mammillary bodies in memory, there is evidence from humans that suggests damage to the mammillary bodies is associated with memory deficits. Several cases of brain damage involving the mammillary bodies as well as cases of tumor-related damage to the area of the mammillary bodies suggests that damage to the mammillary bodies is linked to anterograde amnesia. Indeed, mammillary body dysfunction has been identified as a major factor in diencephalic amnesia, a type of amnesia that originates in the diencephalon (Korsakoff's syndrome, an amnesia that is seen primarily in long-term alcoholics, is one type of diencephalic amnesia).Experimental evidence from animal studies also underscores the importance of the mammillary bodies in memory. Studies with rodents and monkeys have found deficits in spatial memory to occur after damage to the mammillary bodies or the mammillothalamic tract. In addition to involvement in memory functions, there are cells in the mammillary bodies that are activated only when an animal's head is facing in a particular direction. These cells are thought to be involved in navigation and may act somewhat like a compass in creating a sense of direction.Vann SD, & Aggleton JP (2004). The mammillary bodies: two memory systems in one? Nature reviews. Neuroscience, 5 (1), 35-44 PMID: 14708002... Read more »
Figure from Gauthier et al. (2005).
Alzheimer's Disease (AD) and other dementias are progressive neurodegenerative conditions that unfold over time. Subtle symptoms such as forgetfulness and word finding problems may progress to mild cognitive impairment (MCI), and then escalate to full-blown dementia. Recent efforts to classify prodromal states have included automated analysis of spontaneous... Read more »
Berisha V, Wang S, LaCross A, & Liss J. (2015) Tracking discourse complexity preceding Alzheimer's disease diagnosis: a case study comparing the press conferences of Presidents Ronald Reagan and George Herbert Walker Bush. Journal of Alzheimer's Disease, 45(3), 959-63. PMID: 25633673
Fraser, K., Meltzer, J., & Rudzicz, F. (2015) Linguistic Features Identify Alzheimer’s Disease in Narrative Speech. Journal of Alzheimer's Disease, 49(2), 407-422. DOI: 10.3233/JAD-150520
Thomas, C., Keselj, V., Cercone, N., Rockwood, K., . (2005) Automatic detection and rating of dementia of Alzheimer type through lexical analysis of spontaneous speech. IEEE International Conference, 1569-1574. info:/10.1109/ICMA.2005.1626789
A peculiar new paper proposes the idea of "connecting two spinal cords as a way of sharing information between two brains". The author is Portuguese psychiatrist Amílcar Silva-dos-Santos and the paper appears in Frontiers in Psychology.
Frontiers are a publisher with a troubled history of publishing dubious science. But this paper is unusual, even by Frontiers' standards, because it contains virtually no science at all.
In a nutshell, Silva-Dos-Santos suggests that it would be interest... Read more »
Silva-Dos-Santos A. (2017) The Hypothesis of Connecting Two Spinal Cords as a Way of Sharing Information between Two Brains and Nervous Systems. Frontiers in psychology, 105. PMID: 28197119
New York street art. Photo inWikimedia Commons posted by Pedroalmovar.Oxytocin, commonly known as “the love hormone”, is a small chemical that is produced in the brain of mammals, but can both act as a neurotransmitter and enter the blood stream and act as a hormone. It has long been heralded for its role in both maternal and romantic love, but more recent research is showing us just how complicated the physiology of love can be.Oxytocin is released in mammalian mothers after birth. It promotes nursing and bonding between a mother and her young. As children grow, oxytocin is involved in how both mothers and fathers “baby-talk” and mirror their children. It is involved in pro-social behaviors in both young and adults: trust, generosity, cooperation, hugging, and empathy. And of course, oxytocin promotes positive communication and pair bonding in romantic couples. Countless studies have found these relationships between affiliation and oxytocin in many mammalian species, giving oxytocin its commonly used nickname “the love hormone”.But more recent studies show that it’s not so simple.In a number of recent studies, people have been given oxytocin nasal sprays and tested for various behavioral effects in different contexts… and the context really seems to matter. Oxytocin increases trust, generosity, cooperation, and empathy towards people we already know and like. But it decreases trust, generosity, cooperation, and empathy towards strangers. When we play games with strangers, oxytocin makes us more jealous when we lose and it makes us gloat more when we win. It also seems to enhance many attributes relating to ethnocentrism: It increases our ability to read facially-expressed emotions in people of our own race while making it harder to read facial expressions of people of a different race. When forced to choose between being nice to a stranger of our own race versus a stranger of another race, oxytocin makes us more likely to choose the person of our own race. In studies of both people and rodents, oxytocin decreases aggression towards our families and friends, but increases aggression towards strangers.Oxytocin is not the universal love hormone we once understood it to be. It helps us direct our positive support towards our “in-groups” (our family and friends) and defend them from our “out-groups” (individuals we don’t know). It is a delicate balance: Too little of it can cause social impairment and make it difficult to connect with loved-ones; Too much of it can increase our anxiety towards strangers and racist tendencies. And to make things more complicated, each of us has a slightly different oxytocin system: sex, gender, social history, history of childhood trauma or neglect, psychiatric illnesses and genetic variations all have profound effects on the oxytocin system.There is much we don’t know about the role of oxytocin and love. But they are a good fit, because both, it seems, are complicated.Want to know more? Check these out:Shamay-Tsoory SG, & Abu-Akel A (2016). The Social Salience Hypothesis of Oxytocin. Biological psychiatry, 79 (3), 194-202 PMID: 26321019 Zik JB, & Roberts DL (2015). The many faces of oxytocin: implications for psychiatry. Psychiatry research, 226 (1), 31-7 PMID: 25619431 ... Read more »
Zik JB, & Roberts DL. (2015) The many faces of oxytocin: implications for psychiatry. Psychiatry research, 226(1), 31-7. PMID: 25619431
Personality has often been conceptualized a a human feature shaped largely by nurture and environment.Unlike major neuroscience medicine disorders, personality features have been considered less influenced by brain structure and genetic influences.A recent brain structure (morphology) study puts these assumptions at risk.Roberta Riccelli along with colleagues in Italy and Florida State University studied brain structural features across 507 participants in the Human Connectome Project.All subjects completed a personality assessment using the five-factor model (FFM), a widely validated measure of five personality features.Here were the key findings from the study for each personality feature:High neuroticism: increased cortical thickness in supramarginal gyrus, superior parietal cortex, superior temporal cortex, superior prefrontal cortex and frontal pole. Also decreased surface area of superior parietal cortex, middle temporal gyrus, cuneus, superior prefrontal cortex and frontal pole.High extraversion: increased cortical thickness in precuneus and lower surface area and volume of superior temporal gyrus. Also lower cortical volume of entorhinal cortex and greater folding in the fusiform gyrus.High openness: lower cortical thickness in the postcentral gyrus, rostral anterior cingulate cortex, superior prefrontal cortex and lateral occipital gyrus. Increased surface area, cortical volume and folding in a series of parietal, temporal and frontal regions.High Agreeableness: Decreased cortical thickness, surface area, cortical volume and local gyrus formation in frontotemporal regions. Increased local gyrus formation in inferior temporal gyrus.High concientiousness: increased cortical thickness in prefrontal cortex along with lower surface area and cortical volume in middle/inferior temporal gyrus and lateral occipital gyrus regions. Decreased cortical folding in prefrontal gyrus and several other regions.These findings are of note for the diffuse number and types of structural correlates of personality features in man. The authors note the importance of the prefrontal cortex in personality: "significantly evolved in human beings and great apes relative to other species. This could reflect that several FFM personality traits are linked to high-level socio-congnitive skills as well as the ability to modulate "core" affective responses."Look for more structural, functional and genetic study of the five factor model of personality features in human to come.Readers with more interest in this research can access the free full-text manuscript by clicking on the PMID link in the citation below.Follow the author on Twitter WRY999Photo of bald eagle head in profile is from the author's bird photography file. Riccelli R, Toschi N, Nigro S, Terracciano A, & Passamonti L (2017). Surface-based morphometry reveals the neuroanatomical basis of the five-factor model of personality. Social cognitive and affective neuroscience PMID: 28122961... Read more »
Riccelli R, Toschi N, Nigro S, Terracciano A, & Passamonti L. (2017) Surface-based morphometry reveals the neuroanatomical basis of the five-factor model of personality. Social cognitive and affective neuroscience. PMID: 28122961
A new paper challenges a decades-old theory in neuroscience: Split brain: divided perception but undivided consciousness
According to the famous work of Roger Sperry and Michael Gazzaniga, "split brain" patients seem to experience a split in consciousness: the left and the right side of their brain can independently become aware of, and respond, to stimuli. Split brain patients are those who underwent surgery to sever the corpus callosum, the nerve tract connecting the two hemispheres of ... Read more »
Pinto Y, Neville DA, Otten M, Corballis PM, Lamme VA, de Haan EH, Foschi N, & Fabri M. (2017) Split brain: divided perception but undivided consciousness. Brain : a journal of neurology. PMID: 28122878
President Trump this week repeated an assertion he made shortly after his election: that millions of ballots cast illegally by undocumented immigrants cost him the popular vote. If true, this would suggest the wholesale corruption of American democracy.
Not to worry: As far as anyone knows, the president’s assertion is akin to saying that millions of unicorns also voted illegally.
- In a
... Read more »
Preller, K., Herdener, M., Pokorny, T., Planzer, A., Kraehenmann, R., Stämpfli, P., Liechti, M., Seifritz, E., & Vollenweider, F. (2017) The Fabric of Meaning and Subjective Effects in LSD-Induced States Depend on Serotonin 2A Receptor Activation. Current Biology. DOI: 10.1016/j.cub.2016.12.030
Wacker, D., Wang, S., McCorvy, J., Betz, R., Venkatakrishnan, A., Levit, A., Lansu, K., Schools, Z., Che, T., Nichols, D.... (2017) Crystal Structure of an LSD-Bound Human Serotonin Receptor. Cell, 168(3), 377-2147483647. DOI: 10.1016/j.cell.2016.12.033
Do you write about peer-reviewed research in your blog? Use ResearchBlogging.org to make it easy for your readers — and others from around the world — to find your serious posts about academic research.
If you don't have a blog, you can still use our site to learn about fascinating developments in cutting-edge research from around the world.
Research Blogging is powered by SMG Technology.
To learn more, visit seedmediagroup.com.