New Genetic Test Predicts Alzheimer’s 10 Years Earlier

 You don’t need to have a family history of Alzheimer’s to develop the disease, but having a parent or sibling with Alzheimer’s does increase your chances. The risk becomes even higher if more than one close family member is affected. When Alzheimer’s appears repeatedly in the same family, it can be due to inherited genes or lifestyle factors like poor sleep, smoking, high blood pressure, or diabetes that make the risk even greater.

Link : https://www.alz.org/alzheimers-dementia/what-is-alzheimers/causes-and-risk-factors/genetics

Researchers at the University of Oxford used brain scans and genetic data from the UK Biobank to study how our genes shape both the structure and function of the brain. By analyzing thousands of brain imaging measurements, they identified over 100 genetic regions linked to differences in brain size, connectivity, tissue makeup, and other features. Some of these genes are involved in how brain pathways develop, while others relate to iron levels in the brain, which are important for understanding diseases like Alzheimer’s and Parkinson’s. Overall, the study provides a major resource for discovering how genetics influences brain health and may help scientists better understand and treat neurological disorders in the future.

Link : https://www.ox.ac.uk/news/2018-10-12-first-genetic-analysis-brain-function-and-structure-using-uk-biobank-imaging-data

Commentary: A new genetic screening test can predict Alzheimer's disease a decade before symptoms begin by analyzing a combination of risk genes and epigenetic markers. This test could be used to identify individuals who may benefit from early interventions. The work demonstrates how genetics is reshaping preventive medicine. It also raises ethical concerns: should people know their future disease risks, especially when treatment options are limited? Still, this discovery brings science closer to early detection and intervention in neurodegenerative diseases.

Every Brain Needs Music

 One of the most fundamental aspects of the human condition is the creation, consumption, and subsequent adoration of music. Think of your favorite song right now, this is called "audiation", as you do this synapses in your brain fire in a pattern similar to brains that are actively listening to music. In fact music is so fundamental to our brains, that there are specific cell clusters in the auditory cortex of the human brain that only activate in response to music and sounds with musical qualities (i.e. ringtones, jingles, etc.). 

An fMRI of a brain listening to music

Not only does music feel good emotionally, it also may help prevent and lessen the effects of degenerative cognitive conditions such as Alzheimer's. For a long time it was assumed that humans stopped producing new neurons after they were born. This assumption was based on a simple fact, neurons themselves do not go through mitosis. Therefore, the rationale was, no mitosis, no new neuron cells. It is now known that while neurons themselves cannot divide, the stem cells that produce neurons can divide well into adulthood, this is called neurogenesis. Neurogenesis is well documented in the pharmaceutical industry as many medications for the treatment of depression and anxiety such as SSRIs and SNRIs actively stimulate neurogenesis. It is well documented now too that listening to music can stimulate a bit of neurogenesis. Playing music can stimulate even greater neurogenesis creating meshes of new neurons and synaptic pathways in the brain. These additional and strengthened neural pathways give the brain a surplus of neurons that can help resist and soften the effects of diseases like Alzheimer's without the use of medication. 

Pianist and OHSU Neuroscientist Dr. Larry Sherman playing piano

This is a very interesting field of research because it is clear that the act of music has lasting effects on our brain's chemistry. Future questions could potentially investigate if there is any epigenetic effects that correlate with long term music use. Given the fact that no other primates make music in the way humans do, it would be interesting to see if there is/are a "music gene(s)". It also goes to show that learning music is not only good for the soul, it is objectively good for your body. So make sure to eat your vegetables, get plenty of sleep, and enjoy your favorite musical artists, your body will thank you!

Link to article here

A Single Transcription Factor Changes Ants to Queens

 

Indian jumping ants are able to adapt to the loss of the queen ant by making a switch to queen-like status in order to keep the colony functional. According to a study done in Cell, this ability to shift into the queen is caused by the response of the Kr-hl transcription factor to hormones which are present in different levels within the queen and the worker ants. Furthermore, another study has shown that these specific ants have the ability to change the size of their brains and expand their glial cells in order to compete for the status of the queen. This shows that studying ants is an effective way to see how "turning off certain genes can affect ingrained patterns of behavior." These researchers have also studied how different hormones activates the Kr-hl transcriptional factor differently in the queen and worker ants. These juvenile hormones have also impacted how ants develop over time. The studies have concluded that there are still many questions that need to be further investigated, but there is a good possibility that these mechanisms can be present in other organisms as well. 

Thirteen New Alzheimer's Genes Identified: What This Could Mean.

 

    In an article posted on neurosciencenews.com titled "Thirteen New Alzheimer’s Genes Identified", a whole genome sequencing study is outlined to have revealed thirteen new genes linked to Alzheimer's Disease, as well as a novel link between synaptic function and Alzheimer's. Led by Dr. Rudolph Tanzi, PhD, vice chair of Neurology and director of the hospital’s Genetics and Aging Research Unit, this study is the first of its kind to utilize whole genome sequencing in the context of Alzheimer's research, as the genome wide association study (GWAS) was previously used as the predominant mode of identifying AD genes. The cons of the GWAS are established in the article, stating "A standard GWAS misses the rare gene variants (those occurring in less than 1% of the population), a problem solved by the WGS, which scans every bit of DNA in a genome (Neuroscience News, 2021). As expressed, the WGS process of the study was comprehensive, with the whole genomes of 2,247 individuals from 605 families (with documented AD diagnoses), and 1,669 unrelated individuals being analyzed.

            The thirteen identified novel genes are associated with synaptic function, neurodevelopment/neurogenesis, and neuroplasticity. This newly established understanding of the involvement of synaptic function and neuroplasticity with AD may suggest that genetic predisposition and/or epigenetic markers pertaining to abnormal synaptic function are far more important in the development of AD than previously thought. With this in mind, new research which specifically explores synaptic function/dysfunction and neuroplasticity in AD patients of varying stages would shed immense light into how these genes are manifested as functional phenotypic expressions. This research may also confirm the Amyloid Hypothesis and its connection with synaptic dysfunction (The accumulation of oligomerized, self-aggregated amyloid-beta is the primary cause of synaptic dysfunction, the buildup of senile plaques, and subsequent neurodegeneration), though the Tau Hypothesis may also be confirmed with the same logic, as Tau neurofibrillary tangles are also a demonstrable cause of synaptic dysfunction. Another unexplored question pertaining to the research is the following; Did these genes express prior to, or only after the development of AD? If these genes are expressed prior to the development of AD, then development of the disease may be highly predicated on the expression of such genes. Conclusively, the use of WGS in AD research to identify these thirteen genes is groundbreaking, and new drugs which target synaptic function and potentially initiate neurogenesis may prove to be hopeful developments in the treatment of Alzheimer's. 

References & Information:

Article: https://neurosciencenews.com/alzheimers-novel-genes-18168/

Alzheimer's Disease: https://www.alz.org/alzheimers-dementia/what-is-alzheimers#:~:text=Alzheimer's%20is%20a%20progressive%20disease,and%20respond%20to%20their%20environment.

Autism Gene Study Finds Impact on Brain’s Growth Signaling Network

    According to Scripps Research Institute, damage to the gene Dyrk1a sets off a cascade of problems in the development of the brain. Specifically, it results in abnormal growth-factor signaling. The Dyrk1a gene is associated with autism. This results in underdeveloped neurons and have smaller than average brain size. In this study, mice were used as test subjects. The mice with the damaged Dyrk1a showed smaller brain size compared to the normal mice. Page says that “this study suggests there may be a point of convergence for multiple autism causes.” This finding can help develop treatment that can treat many different autisms. They can use genetic mapping and use common molecular target therapy to treat autisms that stem from genes that set off a similar cascade of problems.

                       Caption: The brain on the right is the underdeveloped brain with the damaged Dyrk1a gene.

Articles:

https://neurosciencenews.com/asd-genetics-undergrowth-brain-18199/

https://www.biologicalpsychiatryjournal.com/article/S0006-3223(21)00079-2/fulltext

Discovery of Zombie Genes that Activate after Death

    After humans die, some cells increase their activity and grow to huge proportions. Fresh human brain samples were collected from postmortem brains to understand human neuropsychiatric disorders. While comparing postmortem brain samples to fresh human neocortex samples, the fresh human brain transcriptome had an entirely unique transcriptional pattern. To understand this difference, scientists measured genome-wide transcription as a function of time from the moment of the fresh tissue removal to mimic the postmortem tissue. Within a few hours, there was an increase in astroglial and microglial gene expression. The gene expression of the two types of cells occurred for twenty-four hours after tissue resection. The understanding of this phenomenon is important to scientists that study human brain disorders. The scientists must account for this when studying human brain disorders. 

Article Links: 

https://neurosciencenews.com/death-zombie-genes-18093/

https://www.nature.com/articles/s41598-021-85801-6

Changes of the Brain Causing the Drive of Alcohol Dependence

Alcoholism is a dangerous addiction in which neurotransmitters are the pathways of addiction. Each person is different and handle the affects differently.

Recently, scientists at The Scripps Research Institute conducted a study in alcoholism that could possibly help develop personalized treatments for individuals. Both alcohol-dependent and nondependent rats were used to show the main difference in their brains when given alcohol. It was shown that when given alcohol, there was increase in activity in the central amygdala. According to their studies, the activity was due to two separate signaling pathways in the brains. In nondependent rats, their brain activity increased L-type voltage-gated calcium channels (LTCCs) which boosted the release of GABA, a neurotransmitter, and when blocked, it reduced voluntary alcohol consumption. In the alcohol dependent rats, it was the opposite and there was a decrease in LTCCs. They researchers had found that a stress hormone (CRF) and its type 1 receptor (CRF1) drove the increase of activity and by blocking the CRF1s, voluntary alcohol consumption had decreased.

This could help researchers in developing more personalized treatments to those who have problems with alcoholism by seeing how the individual’s brain react to the different therapeutics. I think this would be great for those who seek out help if they have an alcohol problem. It would make it less stressful to go through therapy knowing what happens to the brain and how it could be addressed.

Scripps Research Institute. "Surprising brain change appears to drive alcohol dependence." ScienceDaily. ScienceDaily, 12 April 2017.

<www.sciencedaily.com/releases/2017/04/170412132352.htm>.

https://pubs.niaaa.nih.gove/pulications/aa77/aa77.htm 

Gene implicated in human language affects vocal communication in mice

A new study published in the journal "Frontiers in Behavioral Neuroscience" has found that ultrasonic vocal communications in adult mice is affected by the same gene needed for speech in humans.

The Forkhead Box protein 2 (FOXP2) gene regulates speech production in humans, and aberrations of this gene result in an impairment of speech production and comprehension.

"This study supports the 'continuum hypothesis,' which is that FOXP2 affects the vocal production of all mammals and not just humans," said senior author Dr. Erich Jarvis, of Duke University Medical Center, Howard Hughes Medical institute and the Rockefeller University.

26 Male mice were bred to have a deficit of FOXP2 protein equivalent to that found in humans known to have speech problems. 24 wildtype mice with a normal level of FOXP2 were also bred. The mice were then housed in a multitude of unique conditions and scenarios and their vocal patterns analyzed. Results concluded that FOXP2 heterozygotes have difficulty producing the complex vocal communication patterns that wildtype mice were able to produce with ease. This was measured both by syllable length, as well as number of unique syllables produced over time. Wildtype males were three times as likely as heterozygotes to produce the most complex syllable types and sequences available for review.

Further analysis also revealed that the heterozygotes vocal motor neurons were more widely distributed across the cortex than was the case for wildtype mice, suggesting that FOXP2 effects both the placement and functioning of neurons for effective communication, in both mice and humans.

Genes for Speech May Not Be Limited to Humans

It is widely believed that mice have no or rather extremely limited neural circuitry that allow them speak, however, studies have shown that mice do in fact communicate using a form of vocalization. Dr. Jarvis, the lead investigator studied the effects of mutation in the Forkhead Box Protein #2 (FOXP2) gene, which regulates the vocalization patterns in humans. Those whom have mutations in this gene tend to struggle with speech impediments. They are unable to master the “coordinated sequences of syllables/phenomes for fluent speech.”² Dr. Jarvis and his team found that the same effect can occur in mice as well. Even more so, according to Dr. Jarvis, this supports the hypothesis that the FOXP2 gene affects not only humans, but all mammals.

The study compared the differences in the sequence and duration of the ultrasonic vocalizations (USVs) of heterozygous male mice with the FOXP2 mutation and healthy wild-type male mice. The results showed that wild-type mice were able to produce complex vocal communication with ease in the presence of active female mice. Heterozygous mice with the FOXP2 deficiency were three times likely to have difficulty in producing complex syllable length and variability over a period of time.

     

The vocal motor neurons of heterozygous mice were also studied and Dr. Jarvis and his team found that they are spread more widely across the cortex than that of wild-type mice. This leads them to believe that the FOXP2 gene mutations not only changes the quality of communication, but the location of the neurons in both mice and humans. 

Although previously the FOXP2 gene was thought to play a slight role, Dr. Jarvis "believes the FOXP2 gene already had a pre-existing role in regulating vocal communication before human communication evolved."1

References:

 1. Frontiers. "Genes for speech may not be limited to humans: Study shows vocal communication in mice is affected by the same gene needed for speec h in humans." ScienceDaily. ScienceDaily, 15 November 2016. www.sciencedaily.com/releasses/2016/11/161115114333.htm. 

 2. Johnathan Chabout, Abhra Sarkar, Sheel R. Patel, Taylor Radden, David B. Dunson, Simon E. Fisher, Erich D. Jarvis. A Foxp2 Mutation Implicated in Human Speech Deficits Alters Sequencing of Utrasonic Voclizations in Adult Male Mice.Frontiers in Behavioral Neuroscience, 2016; 10 DOI: 10.3389/fnbeh.2016.00197

Mutation in Shank3 Gene Can Lead to Different Psychiatric Disorders

Diagnosing and treating psychiatric disorders is a complex task, understanding the causes of these diseases is even more intricate and complex.  Neuroscientists at MIT are examining mutations on one gene, Shank3, that has been linked to autism and schizophrenia.  Shank3 encodes for a scaffold protein which organizes hundreds of other proteins found on the post-synaptic cell membrane.  Synapses are structures between neurons that help transmit electrical and chemical signals across the brain and nervous system.  Through ongoing research the scientist found that different mutations on the Shank3 gene, in mice, produce different psychiatric behaviors.  In 2011 scientists found that the absence of the Shank3 protein induced two common behaviors of autism- social avoidance and compulsive, repetitive behavior.  Years earlier, researchers at the University of Montreal found a mutation in the Shank3 gene in patients schizophrenia.

The scientists interested with the current research on Shank3 engineered mice to have the two different mutations of the Shank3 gene; one in which the protein was truncated and caused schizophrenic behavior and the other in which the absence of the Shank3 protein caused autistic behavior.  The mice also shared many common behaviors but also possessed the hallmark behaviors of their respective disorders.  By activating the mutations in different parts of the brain at different stages of development researchers were able to narrow down the brain circuits these mutations effected.  The autism mutation exerted its effects early in development, primarily in the region of the brain known as the striatum, these region is responsible for coordinating motor planning, habitual behavior and motivation.  The schizophrenia mutation exerted its effects later in development, suggesting that the truncated protein can function sufficiently early in development.  However as development continued the truncated proteins interfered with the synapses of the cortex, where executive function occur.

The brain is by far the most complex organ in our bodies, it is remarkable to think that essentially a pile of jelly is responsible for all of the thought, behavior, emotion, and movement that occurs in everyday life.  As if the brain isn't complex enough to understand, psychiatric disorders and the causes of those disorders are equally as complex.  The research being conducted by this group of scientists is aiming to understand the potential cause of these psychiatric orders and to also understand the brain circuits these defective proteins effect in order to tailor treatments for individuals affected by these disorders.  

Ctenophore Genome Sparks the Theory that the Neuron has Evolved Twice

Recent research in neuroscience and genetics has led to the idea that the neuron, previously thought to have only evolved once, has gone through two separate spurts of evolution. By examining the genome and neuromuscular structure of ctenophores, researchers are finding that the nervous system and immune system of this clade of animals has come around almost entirely independent from other animal groups - from the closely related proiferans to our own bilaterian grouping. The researchers examined the genomes of two model ctenophores, Pacific sea gooseberries and comb jellies (pictured above), to examine how these species expressed genes involved in their muscular system, nervous system, and immune system. The researchers used the genomes to place ctenophores at the base of the phylogenetic tree (pictured below), adding to the idea that ctenophores likely evolved separately from the rest of animal phylogeny. The examination of the immune system genetics found that the ctenophore immune system differs greatly from bilaterians, sponges, and cnidarians, lacking rather important pattern recognition markers. Genes involved in body patterns and axis formations were also found lacking in the ctenophores, despite being present in all metazoans. The examination of the nervous system of ctenophores found that ctenophores use practically none of the neurotransmitters known to be used in cnidarians and bilaterians (i.e. serotonin, adrenaline, dopamine, glycine, acetylcholine), suggesting these neurotransmitters are adaptations of the later cnidarian and bilaterian lines. While there are some neuron-related genes in the ctenophore that are shared by bilaterians, the neurons of the ctenophore do not express these shared genes. The similarity between ctenophores and later metazoans along with the stark differences in the nervous, muscular, and immune system as well as the genetic identification of ctenophores as a basal group supports the idea that ctenophores evolved independent from and parallel to the later metazoans. 

In easier terms, the findings of this research give way to the idea that the ctenophore phylum evolved separately from other phylums. This contrast previous ideas of ctenophores as an ancestor to later species and groups. This finding is especially interesting in the scope of neuroscience, as the previous way of thinking had the ctenophore nervous system as an ancestral system for later species, including bilateria. This research leads us to believe that, instead of a single, continual development of the nervous system, the nervous system instead evolved in two separate events - that of the ctenophore and that of the following phylums. This researching finding means that there are two entirely separate organizations of the nervous system that have evolved entirely independent of each other. Looking at nervous system evolution through this light means that the origin and evolution of our own nervous system is not as clear as we had once thought.

(second phylogeny image source: https://whyevolutionistrue.wordpress.com/2013/12/20/the-outgroup-for-animals-ctenophores/) 

Touch-Sensory Principle Protein Identified

The concept of touch and the mystery of how it is felt has always been a mystery in the scene of neuroscience. However, biologists at The Scripps Research Institute have identified a protein that brings about touch in mammals. Earlier in April 2014, TSRI was also the first to identify the dual-sensor system and nerve-touch sensation through relation to Merkel cells revealed by the supporting article. Last year, the same scientists discovered ion-channeled proteins Piezo1 and Piezo2 through studying its effects on mice. This year, they discover that only Piezo2 is the primary protein that when activated in Merkel cells, sends the feeling of touch through the nervous system. During the current study, they note that when Piezo2 protein is removed from newly bred mice (by deleting the gene!), all mice died at birth. However, when Piezo2 is removed during an adult stage of the mice's life, the mice is almost incapable of feeling light touches but still able to feel harsher pains through observation of reactions.

I found these articles interesting because I love any science that deals with the 5 senses because of the science involved that produce these sensations and now can come closer to understanding human existence. This neuroscience study included parts where scientists actually removed a whole protein gene from the mice which I found was interesting. The concept of touch can now be applied to how light and other sensations felt by touch can now be studied through these Piezo2 ion channels. I cannot wait for the next big discovery TSRI has to offer. 

Original: http://www.sciencedaily.com/releases/2014/12/141202161427.htm

Supporting: http://www.sciencedaily.com/releases/2014/04/140406162245.htm

Genes Could be the Key to a Good Memory

A study was conducted to find a connection between genetic variants and the ability to remember stories and lists. This study is the first of its kind.

The researchers had participants who were all free of dementia take memory tests. The tests consisted of remembering stories and words after a certain period of time.

The researchers analyzed the results of the tests in conjunction with individual genome information. They then determined which genetic variants were linked with lower memory test scores. The results for individuals who possessed certain genetic variants showed early signs of Alzheimer’s disease.

The individuals found to have lower scores were found to have variants near the Apolipoprotein E gene, which is involved in immunity. Some previous research has shown that a number of forms of Apolipoprotein E are connected to a higher risk for dementia and related diseases.

The researchers also studied over 700 postmortem brain tissue samples. After studying the samples, they determined that individuals with the genetic variants studied in this experiment were more likely to have signs of Alzheimer’s.

They hope that their discoveries can help scientists understand the link between genes, immune systems, and memory loss due to age.

This article was interesting to read but not surprising to me. It's clear that our genes affect nearly everything about us, so it always seemed likely that genes would affect memory and aging as well. Hopefully, this helps scientists and clinical professionals better understand the exact sources of problems to either fix them or help improve treatment options for aging patients.

Article: http://www.medicalnewstoday.com/articles/286106.php
Secondary Link: http://www.medicalnewstoday.com/articles/265432.php

Transgender Monkeys Genetically Modified are the New Way to Go

For two years Scientist Anthony Chan created genetically modified transgender monkeys. In his experiment, he found that 3 out of the 5 monkeys developed Huntington Disease. The symptoms were so severe the monkeys has to be killed within the month of having the disease. Chan is hoping the primates will be the future models instead of mice. Chan believes that primates will accelerate basic research in neuroscience. This will help researchers mad and text the complex neural circuits underlying the behavior that cannot be found in simpler organisms. Monkeys are already superior to mice since they can replicate disorders easier in monkeys than mice like autism, Alzheimer, and schizophrenia. Mice also have failed to fully show how drugs will actually effect human beings. Mice however are cheaper and easier to obtain. They also show signs faster for researchers to observe.

Its been known that humans and primates can be compared because they carry similar traits. Now the idea of using primates to conduct neuroscience experiments is interesting and exciting. The use of primates could help researchers better understand disorders and diseases who do not have cures - just yet.


http://www.scientificamerican.com/article.cfm?id=precision-gene-editing-paves-way-for-transgenic-monkeys

Centipede Toxin Kills Pain

Chinese red-headed centipede

    In a test done by Glenn King of the University of Queensland in St. Lucia, Australia,  purified a molecule of 46 amino acids from the toxin, or venom of the Chinese red-headed centipede.  When it was tested in rat neurons by IV, the peptide inhibited pain-associated sodium ion channel and had little effect on related channels.
    Researchers then compared the molecule injected into mice that were exposed to noxious chemicals or heat and saw that the higher the does the less they felt pain and showed no obvious side effects.  The researchers came to the conclusion that this molecule and maybe others from centipede toxins could provide powerful pain treatments for chronic pain. However it only mentioned the studying being done with Chinese red-headed centipedes, so it leaves me to wonder how other centipede venom would act.  I thought this was a very interesting article, like I stated above though, I wonder if other centipede venom reacts the same way or if different centipede venom can help with things other than pain.

http://doi.org/n35
http://ezproxy.stockton.edu:2048/login?url=http://search.proquest.com.ezproxy.stockton.edu:2048/docview/17584456?accountid=29054

Genes That Impact On Remembering, Forgetting And Learning

According to an article published in Medical News Today,  biologists at the University of Utah have discovered that certain genes and proteins help to improve individuals' memory and have a large impact on remembering, forgetting and learning, but they may also cause an addiction. These genes and proteins were first found to promote embryonic growth and development.

I found this finding helpful because if memory could be effectively improved, learning would be much easier. And we could learn more things within a shorter period of time if we are able to remember what we learn faster and longer than we do, learning would have much more fun.

Genetic Differences in Scouting vs. Non-Scouting Bees

An article in Medical News Today, features a study on honey bees and genetic variations between scouting bees and non-scouting bees. Bees that are considered to be scouting bees are females that go out and search for food all on their own, never being told where to go. When they find one, they fly back to their colony and perform what is known as the "waggle dance" to relay the message of the new food source to the rest of the bees.

Scientists conducted an experiment to test the genetic differences between scouting and non-scouting, or foragers. The did this by enclosing bee hives in a large mesh cage so the bees could not escape and placing a specific food source outside of the hives, letting the bees get used to it. A couple days later, a new food source was added to the enclosed area in different locations than the original food source. Researchers observed which bees found the food source first and painted a colored dot on them to keep track of them.

The process of adding a new food source and marking the bees was done two more times so some bees had three dots on them. Researchers then separated the scouting bees from the non-scouting bees. Bees with two or more dots on them were considered to be scouting bees. Then, the brains were taken from the captured bees and geneticists examined the differences between gene expression between the two types of bees.

What they found was extremely interesting; 16% of the 7,500 genes in honey bees were significantly different in the two. Some include genes that regulate neurotransmitter receptors of glutamate and dopamine. Even more interesting, when non-scouting bees were treated with octopamine, a chemical that activates the dopamine receptor, they started showing behavior similar to scout bees. Alternatively, when a scout bee was given a glutamate inhibitor, it would act like a forager.

Genetic ADHA Caused By Signaling Pathways in the Brain

Attention-deficit/hyperactivity disorder (ADHD) effects a majority of our youth in America. An article was written in Bio News about genes and how it may correlate to ADHD.  A new gene study on a subset of individuals with ADHD may lead to new treatments of this disorder.  Hakon Hakonarson, M.D., Ph.D., director of the Center for Applied Genomics at The Children's Hospital of Philadelphia led the study stating that "he genes involved affect neurotransmitter systems in the brain that have been implicated in ADHD."  The study began with a complete genome sequence of 1,000 children of European ancestry and compared the subjects with 4,100 children without the disorder.  Researchers found that children with ADHD have alterations in GMR5 genes which effect nerve transmission.  This research may lead to treatments instead of hiding behind the disorder with mind altering harsh drugs.

Gene Mutation for Deafness Also Responsible for Sensitivity to Some Types of Touch

Since 1997, it has been known that mutations to the KCNQ4 K+ channel, a potassium ion pathway only found in three places: 1) on sound-detecting hair cells in the inner ear that leads from the external environment to neurons, 2) a part of the brain stem involved in hearing, and 3) neurons in the skin that help us to sense touch on mutations, lead to progressive deafness. Now a new study on mutations in this same pathway suggests that they also cause heightened sensitivity in skin. The researchers found that in both mice and humans, they disrupt the channel’s buffering ability, which would normally prevent neurons from becoming over-stimulated as stimuli is passed from the channel to the neurons. As this ability to buffer decreases in the inner ear, the hair cells slowly die, which leads to deafness.

[caption id="attachment_3237" align="aligncenter" width="519" caption="The KCNQ4 gene is located on base pair 41,249,683 to base pair 41,306,123 on the short (p) arm of chromosome 1 at position 34, as shown here."][/caption]

Additionally, the team discovered that in mice and human families with this gene mutation, the channel only appeared in neurons in skin that were sensitive to low level vibrations, and that humans with the mutation are better able to discern the subtle differences between various soft materials because of this. They also found that this heightened sensitivity to these types of touch was actually in existence before they went blind, meaning that this sensitivity was not a subsequent adaptation made by the body. Finally, they noted that this particular gene mutation in the KCNQ4 channel is one of many gene mutations that can cause deafness, leading them to conclude that not all those who develop progressive deafness will necessarily develop this type of sensitivity to touch.

The idea that certain traits can be inherited simultaneously (in this case, progressive deafness and increased skin sensitivity) is not a new one – a very common example is sex-linked disorders. However, genetic mutations such as this one are still very mysterious in nature simply due to the fact that there are many similar channels, such as the KCNQ1 channel, that have yet to be studied extensively.

The abstract of the original research article can be found here.

A Step Towards Understanding Your Stutter

A recent study has unearthed a surprising linkage between lysosomal mutations and persistent stuttering problems. Back in February 2010, Dr Dennis Drayna, a senior investigator with the National Institute on Deafness and Other Communication Disorders, and his colleagues published findings of mutations in three genes present in almost all of the stuttering members of a large Pakistani family. More recently, researchers at the Washington University School of Medicine in St. Louis have delved deeper into these previous findings and focused on one of the three genes, NAGPA. With this gene alone, three mutations were observed in most of those who stutter that impaired an enzyme responsible for "addressing" proteins to the lysosome. Of these three mutations, two of them were deemed to be future prospects for stuttering therapies, due to the fact that they do not completely impair the function of the affected protein. Since relatively little is known about the brain and which of it's millions of neurons are responsible for what speech patterns, this study seems to be a step forward in understanding not only stuttering, but also how the brain works.