Latest news with #brain
Yahoo
22-07-2025
- Health
- Yahoo
Dopamine Doesn't Work in Our Brains Quite The Way We Thought
Dopamine is one of the most extensively studied chemical messengers in the human brain, and yet scientists are still figuring out how it works to accomplish so much. For years, the classic view has been that, when released, dopamine slowly diffuses through the brain like a chemical megaphone, broadcasting information far and wide to numerous target cells. Recently, however, that perspective has changed. Newer research suggests that dopamine is also capable of short, sharp whispers, precisely directed within milliseconds to neighboring cells. If researchers are right, this localized signal could be a "fundamental building block" that's overlooked in the brain's dopamine system. Related: Dopamine in the brain is different to dopamine in the rest of the body. In the blood, dopamine helps modulate the function of multiple organs as well as our immune responses. In the brain, it's a chemical messenger involved in mediating a diversity of animal behaviors – from movement and mood to sleep and memory to reward and motivation. Neurons that release dopamine are known to do so with different firing patterns, and yet it's not clear what messages these specific signals encode, or why. The ability to send both fast and slow signals could explain how the brain's dopamine system can achieve so much with such specificity. Under a special microscope, which is well-suited to imaging living tissues, scientists at the University of Colorado and Augusta University in the US triggered a release of local dopamine in the brains of live mice. They then watched, using fluorescent staining, as it activated receptors in only a few, tiny areas of nearby neurons. This short-range activation elicited a rapid neural response. Broader dopamine release, meanwhile, is widespread and elicits a slower response. "Our current research found that dopamine signaling and transmission in the brain is much more complex than we thought," says pharmacologist Christopher Ford from the University of Colorado. "We knew that dopamine plays a role in many different behaviors, and our work gives the beginning of a framework for understanding how all those different behaviors could all be regulated by dopamine." The specific neurons studied by Ford and colleagues come from the brain's striatum – a part of the basal ganglia involved in motor and reward systems that is rich in dopamine-releasing neurons. The striatum receives dopamine inputs from various parts of the brain, and it is implicated in neurodegenerative disorders like schizophrenia, addiction, and ADHD. Parkinson's disease, for instance, is marked by a degeneration of dopamine neurons connecting to the striatum. A better understanding of how dopamine sends signals in this part of the brain could be crucial for coming up with new treatments for a variety of conditions. "We are really only at the tip of the iceberg in trying to understand how dysfunctions in dopamine contribute to diseases like Parkinson's disease, schizophrenia or addiction," says Ford. "More work is needed to grasp how these specific changes in dopamine signaling are affected in these different neurological and psychiatric diseases." The study was published in Science. Related News 5 Questions That Could Reveal a Truth About Your Aging Common Sweetener Could Damage Critical Brain Barrier, Risking Stroke Parkinson's Disease Has a Smell That Some Dogs Can Detect Solve the daily Crossword
Health Line
19-07-2025
- Health
- Health Line
Types of Parkinson's
Key takeaways Parkinson's disease is often caused by the death of cells in the brain that produce dopamine, leading to symptoms like tremors and difficulty with balance and movement. Besides the most common form, idiopathic Parkinson's, there are various other types, including juvenile Parkinson's, drug-induced parkinsonism, and vascular parkinsonism, each with distinct causes and characteristics. Diagnosing Parkinson's involves a review of symptoms, medical history, and neurological tests, and while there's no single test, blood tests, genetic testing, DaTscans, and MRIs can help rule out other conditions. Parkinson's disease is a neurological condition that gets progressively worse over time and causes trouble with movement. It's thought to affect about 1 percent of people over the age of 65. Parkinson's is caused by the death of cells in a part of your brain called the substantia nigra. When these cells die, levels of the neurotransmitter dopamine drop in your brain. This reduction leads to symptoms such as tremors, impaired balance, rigid muscles, and difficulty walking. Collectively these symptoms are known as parkinsonism. Parkinson's disease is attributed to about 85 percent of parkinsonism cases. The other 15 percent of cases are attributed to one of several conditions called atypical parkinsonisms. Learn about the different types of Parkinson's and how they're diagnosed. Idiopathic Parkinson's disease Idiopathic Parkinson's, or simply Parkinson's disease, is the most common cause of parkinsonism. It generally onsets between the ages of 55 to 65 and rarely occurs before the age of 50. Parkinson's onsets gradually as cells in the substantia nigra die and dopamine levels drop. It's thought genetic and environmental factors contribute to the development of Parkinson's. The main symptoms of Parkinson's disease include: Juvenile and young-onset Parkinson's disease Juvenile Parkinson's is a rare condition that onsets before the age of 21. It's referred to as young-onset Parkinson's if it presents before the age of 40. Symptoms are similar to late-onset Parkinson's, but it's more likely to be associated with genetic causes than late-onset Parkinson's. A 2017 study of 108 people with early-onset Parkinson's found that 46.3 percent reported a family history. Drug-induced parkinsonism Drug-induced parkinsonism is the second most common cause of parkinsonism. It occurs when a drug interferes with dopamine transmission in your body. You become more likely to develop drug-induced parkinsonism with age. In a study published in Movement Disorders, researchers found the average age of onset of drug-induced parkinsonism was 70.9. Symptoms are similar to those of Parkinson's disease, including: tremor rigidity slowness of movement gait disturbance Drugs that can lead to drug-induced parkinsonism include: antipsychotics antidepressants calcium channel antagonists gastrointestinal prokinetics antiepileptic drugs Multiple system atrophy Multiple system atrophy is a rare disorder that causes similar symptoms as Parkinson's such as impaired movement, stiff muscles, and poor balance. It most often onsets in your mid-50s. It can lead to changes in areas such as your: heart rate digestion blood pressure bladder control Progressive supranuclear palsy Progressive supranuclear palsy causes problems with balance, walking, swallowing, eye movement, speech, and mental ability. For most people, it onsets in their mid-60s and it tends to progress more rapidly than Parkinson's disease. The exact cause isn't known, but symptoms are caused by a deterioration of cells in your brain stem, substantia nigra, and other parts of your brain. Corticobasal syndrome Corticobasal syndrome is caused by a buildup of a type of protein called tau in your brain. Symptoms vary but can include: trouble controlling a limb on one side of your body muscle stiffness tremors jerky movement spasms slow or slurred speech symptoms of dementia trouble swallowing It usually onsets between the ages of 50 to 70. Dementia with Lewy bodies Dementia with Lewy bodies is a progressive condition associated with an abnormal buildup of a protein called Lewy bodies, or alpha-synuclein, in your brain. It typically onsets after the age of 50 and affects men slightly more often than women. Dementia with Lewy bodies also has the same movement symptoms of Parkinson's, as well as mental symptoms such as: changes in alertness or concentration hallucinations rapid eye movement sleep disorder memory problems trouble processing information or planning Vascular parkinsonism Vascular parkinsonism is thought to be caused by multiple small strokes in the area of your brain that control movement. It can lead to similar symptoms as Parkinson's but tends to mostly affect the lower body. postural instability mostly lower-body parkinsonism shuffling or freezing gait when walking absence of a resting tremor poor response to medication levodopa Because your risk of having a stroke increases with age, your chance of developing vascular parkinsonism is also thought to increase as you get older. Normal pressure hydrocephalus Normal pressure hydrocephalus is a buildup of cerebrospinal fluid in the cavities in your brain. This buildup can put pressure on your brain and cause damage that leads to parkinsonism. Hydrocephalus is most common in adults over 65. The average age of onset is approximately 70 years. About 80 to 95 percent of people experience gait disturbances described as shuffling, magnetic, or a wide-based gait. About 80 to 95 percent of people also experience cognitive changes such as reduced attention, forgetfulness, or poor executive function. About 50 to 75 percent of people experience loss of bladder control. How is each type diagnosed? A doctor trained in neurogenerative conditions diagnoses Parkinson's based on your symptoms, medical history, and results from a physical and neurological test. No single test can diagnosis Parkinson's disease, but tests may be able to rule out other causes of parkinsonism. These tests include: Blood test. Blood tests can't identify Parkinson's disease directly, but they may be able to help your doctor identify other causes of parkinsonism, such as multiple system atrophy or corticobasal degeneration. Genetic testing. Genetic testing may help your doctor identify the underlying cause of your parkinsonism if you have a family history of parkinsonism. DaTscan. A DaTscan is an imagining technique that lets a doctor see how much dopamine is in your brain. If the scan finds an abnormally low amount, it can help confirm your doctor's Parkinson's diagnosis. Magnetic resonance imagining (MRI). An MRI can potentially identify a brain tumor, normal pressure hydrocephalus, or vascular parkinsonism. Takeaway Parkinson's disease and most other causes of parkinsonism have no known cure. But researchers are continuing to learn more about these conditions and how to best control symptoms.
Medical News Today
18-07-2025
- Health
- Medical News Today
What to know about dysdiadochokinesia
Dysdiadochokinesia is the inability to perform quick, alternating movements, such as opening and closing a fist or tapping a foot. It is usually a symptom of an underlying health condition that affects the can affect speech and impair coordination and movement in the upper and lower extremities. It is a type of ataxia, a neurological condition characterized by a lack of muscle conditions that cause dysfunction in the cerebellum can lead to dysdiadochokinesia. The cerebellum is the part of the brain responsible for coordinated movement, balance, and for the movement condition can be challenging, but a combination of therapies can help manage symptoms and improve a person's quality of article looks at the symptoms, causes, and diagnosis of dysdiadochokinesia. It also discusses the treatment and outlook for the of dysdiadochokinesiaDysdiadochokinesia can affect the upper and lower limbs, the laryngeal muscles that control speech, and the muscles involved in eye movement.A person with the condition cannot perform coordinated, rapid, alternating movements. These may include:rapid finger tappingfoot tappingopening and closing a fistquickly flipping the hand from palm side up to palm side downOther symptoms of dysdiadochokinesia include:poor movement coordination in the hands, arms, and legsbradykinesia, movement that is slow or difficultmuscle rigiditycognitive issues, such as problems with memory and languagebalance and gait problemsslow or impaired eye movementsdysarthria, difficulty speaking due to weakness in the muscles necessary for speechdysesthesia, physical sensations such as pain or burning that occur due to neurological damagedysphagia, difficulty swallowingdysmetria, problems with controlling the distance, speed, or range of movementstremorsCauses of dysdiadochokinesiaLesions in the cerebellum are the most common cause of cerebellum is the lower back area of the brain. It is responsible for various functions involving coordination and movement. These include:coordinating the movement of different muscle groupsmaintaining balancecoordinating eye movementslearning motor skillsDamage to this part of the brain can affect a person's ability to perform these and other dysdiadochokinesia always a sign of cerebellar damage?The causes of dysdiadochokinesia are unknown in some cases, however, scientists believe genetics may play a suggests dysdiadochokinesia may sometimes involve variants in genes that control how neurotransmitters communicate messages to the brain and include gene variants that affect a segment of DNA known as CAG trinucleotide repeat. The variants may cause certain DNA building blocks called nucleotides to repeat an unusual number of times within the segment. This can affect the way neurotransmitters communicate and may lead to cell dysfunction and death. Conditions that can cause dysdiadochokinesia Dysdiadochokinesia can occur when there is damage to the cerebellum. There are various potential underlying causes of cerebellar lesions, including the following:Neurodegenerative disorders: Parkinson's disease and Huntington's disease cause lesions in the cerebellum that can lead to sclerosis (MS): Dysdiadochokinesia may be a symptom of disorders that cause inflammation in the brain, such as disease: Some infectious diseases that affect the nervous system can damage the cerebellum. These include cerebellar encephalitis and Lyme disorders: Health conditions that affect metabolic processes like energy production may cause dysdiadochokinesia. These include celiac disease and Hashimoto's Cerebellar strokes can damage the brain and lead to movement and coordination Injury to the brain can result in cerebellar tumor: Structural changes in the brain, such as a tumor, may result in and other substances: Misuse of certain medications, including sedatives and barbiturates, and substances that contain toxins, such as alcohol and illicit drugs, may lead to neurological damage that can affect The psychiatric condition may affect cerebellar function, which could lead to of dysdiadochokinesiaA doctor may begin the diagnostic process with movement tests, such as asking a person to demonstrate turning a doorknob, quickly flipping their hand from palm side up to palm side down, or tapping their may also ask the person to repeat certain syllables, such as 'lala', 'papa', and 'tata' to check for elements of diagnosis may include:assessing a person's gaittesting cognition and languageexamining eye movementschecking muscle toneDoctors may use different methods to diagnose the underlying causes of the movement symptom. These include:Imaging scans: CT, MRI, and PET scans can reveal head trauma or evidence of a stroke that may be the cause of the movement tests: A doctor may use blood tests to check for various potential underlying causes, including metabolic disorders, neuroinfectious diseases, and evidence of spinal fluid (CSF) analysis: A lumbar puncture is a procedure in which a doctor collects CFS from the spinal canal. CSF can help a doctor diagnose certain conditions that can cause dysdiadochokinesia, including neuroinflammatory and neuroinfectious evaluation: This can help doctors determine if the condition is related to a neurodegenerative or psychiatric underlying testing: A geneticist may test for inherited variant genes. »Learn more:What to know about the brainTreatment of dysdiadochokinesiaThere is usually no cure for ataxia like dysdiadochokinesia. Doctors may suggest supportive treatment to help manage the symptoms. According to the United Kingdom's National Health Service (NHS), treatment for ataxia usually involves:physical therapy for movement and coordination issuesoccupational therapy to help with the management of day-to-day challengesspeech and language therapy for speech problems and difficulty swallowingmedication to treat symptoms such as nerve pain, depression, and eye problems»Learn more:How can physical therapy help neurological disorders?Outlook for dysdiadochokinesiaThe outlook for dysdiadochokinesia varies depending on the underlying cause of the condition and a person's overall and severe causes of the movement symptom, like stroke or head trauma, may result in a poorer outlook, especially in people with multiple co-occurring health outlook may be more positive if dysdiadochokinesia is a symptom of an infectious, metabolic, or inflammatory condition, especially with early diagnosis and treatment.»FIND CARE:Search for a neurologist in your asked questionsCan traumatic brain injury lead to dysdiadochokinesia?Traumatic brain injury can lead to dysdiadochokinesia if it causes damage to the brain injury can lead to dysdiadochokinesia if it causes damage to the does dysdiadochokinesia differ from ataxia?Dysdiadochokinesia is a type of refers to a group of disorders that affect movement, coordination, balance, and speech. Like dysdiadochokinesia, ataxia is typically a symptom of an underlying is a type of refers to a group of disorders that affect movement, coordination, balance, and speech. Like dysdiadochokinesia, ataxia is typically a symptom of an underlying is the "DANISH" mnemonic in relation to dysdiadochokinesia?A simple way to remember the characteristic signs of cerebellar dysfunction is the DANISH mnemonic: D: Dysdiadochokinesia/dysmetria A: Ataxia N: Nystagmus I: Intention tremor S: Speech H: HypotoniaA simple way to remember the characteristic signs of cerebellar dysfunction is the DANISH mnemonic: D: Dysdiadochokinesia/dysmetria A: Ataxia N: Nystagmus I: Intention tremor S: Speech H: HypotoniaSummaryDysdiadochokinesia is an inability to perform rapid, alternating movements, such as tapping a foot or turning a doorknob back and forth. It affects the upper and lower limbs, the muscles that control eye movement, and the laryngeal muscles involved in movement condition is typically a symptom of an underlying condition that causes lesions to the cerebellum. The cerebellum is the area of the brain responsible for many types of movement, balance, and for dysdiadochokinesia typically aims to manage the symptoms. The outlook for the condition varies depending on the underlying cause.
Daily Mail
16-07-2025
- Health
- Daily Mail
The real reason you walk into a room and immediately forget why you're there, according to science
As a permanently sleep-deprived mother of two, it's perhaps not surprising I lose my train of thought on a regular basis, but even before having kids I had experienced that disorienting feeling of walking purposefully into a room and then thinking 'Why on earth am I here?' Chances are you have too. In fact, this might even happen to you on a regular basis, leading you to worry that it's an early indicator of losing your memory. However, the good news is that it's actually a very common phenomenon; so common that it's been dubbed 'The Doorway Effect'. Scientists have researched this particular brain glitch to find out what causes us to forget our intentions as soon as we enter a new room, and come up with interesting results. The Doorway Effect was first documented by the University of Notre Dame in the Quarterly Journal of Experimental Psychology. The research saw participants carry objects through real and virtual environments, analysing how their memory performed across the various settings. The study found participants were most likely to forget what they were holding or doing after walking through a doorway, more so than if they travelled exactly the same distance within one room. This coined the term 'event boundary', a notion that your brain likes to categorise experiences into episodes. A doorway acts as both a physical and psychological barrier that the brain interprets as the end of one event and the beginning of another. As you cross the doorway (or boundary), your memory drops anything it deems irrelevant. The loss of visual cues as you move from one space to another also explains why you forget what you're planning to do. When a person develops an immediate intention, such as charging a phone, the brain connects the task to cues that are visible in its current environment, like a laptop or a desk. As you enter a new room, the brain builds a new mental map of the space, finding anything of relevance. If the original context cues are no longer available, this can hinder the brain from retrieving the goal it set just moments earlier. 'Although annoying, entering a room and forgetting why indicates that your brain is performing exactly as it should by optimising what it deems relevant in the moment and temporarily 'deleting' short-term goals a little earlier than needed,' says HealthTest. I've definitely experienced the 'Doorway Effect' more since becoming a parent, which makes sense because studies have found that those experiencing a high cognitive load are most likely to forget their short-term goals, particularly when switching tasks. Additionally, research at the University of Pennsylvania's Department of Neurology revealed that insufficient sleep impacts short-term memory encoding and retrieval, ensuring that the more tired or 'emotionally busy' you are, the more likely your brain is to forget its task mid-walk. Luckily, there are things you can do to help yourself retain those all-important plans as you move from room to room. Saying your intention out loud as you walk might make your family laugh at you, but it will help cement it in your mind. Another tip is to visualise the task as if you're already doing it when you set your intention, so it's less likely to drop out of your brain as soon as you leave the room. Finally, if you're constantly juggling a long list of tasks (like trying to get yourself and the kids out of the door in the morning), then having visual cues, like a book bag left by the door, or notes stuck around in key places (reminding you to bring the packed lunches etc) can be helpful.
Arab News
15-07-2025
- Science
- Arab News
What We Are Reading Today: ‘In The Brain, In Theory'
Author: ROMAIN BRETTE 'In The Brain, In Theory,' Romain Brette argues that the brain is not a 'biological computer' because living organisms are not engineered. Engineering is the use of knowledge to solve technical problems, to build an artifact with a plan. Brette reviews the main theoretical frameworks for thinking about the brain, including computation, neural representations, information, and prediction, and finds them poorly suited to the study of biological cognition. He proposes understanding the brain as a self-organized, developing community of living entities rather than an optimized assembly of machine components.
