Breaking News
October 23, 2018 - Drugs approved for breast cancer treatment are effective and well tolerated in men
October 23, 2018 - EKF introduces new hand-held lactate analyzer for rapid sports performance monitoring
October 23, 2018 - Researchers identify common genetic connection in lung conditions
October 23, 2018 - Forbius initiates Phase 2a trial evaluating efficacy, safety of AVID100 in patients with squamous NSCLC
October 23, 2018 - Immunotherapy achieves major pathological response in early-stage mismatch repair deficient colon cancer
October 23, 2018 - New discovery may lead to better treatment options for pancreatic cancer patients
October 23, 2018 - FDA Approves Dupixent (dupilumab) for Moderate-to-Severe Asthma
October 23, 2018 - Researchers identify immune culprits linked to inflammation and bone loss in gum disease
October 23, 2018 - Despite lower risk factors, black men have higher rates of recidivism
October 23, 2018 - Study finds why pregnant women in mainland China, Hong Kong and Taiwan prefer cesarean delivery
October 23, 2018 - AbbVie’s U-ACHIEVE Phase 2b/3 dose-ranging study improves outcomes in patients with ulcerative colitis
October 23, 2018 - NCI grant awarded to Abramson Cancer Center to study CAR T cells In solid tumors
October 23, 2018 - Scientists use electron microscope to study chemical transformation in catalytic cross-coupling reaction
October 23, 2018 - Research offers new hope to men who received childhood cancer treatment
October 23, 2018 - Adverse Childhood Experiences Tied to Burnout in BSN Students
October 23, 2018 - High levels of oral disease among elite athletes affecting performance
October 23, 2018 - Study examines effect of immediate vs delayed pushing during labor on delivery outcomes
October 23, 2018 - LU-RRTC to spearhead capacity-building efforts for racial and ethnic populations
October 23, 2018 - Maintenance therapy with olaparib improves progression-free survival in advanced ovarian cancer patients
October 23, 2018 - Organic food may protect against cancers finds study
October 23, 2018 - Interweaving anxiety disorder associated with stuttering remains unrecognized
October 23, 2018 - Cannabis oil shown to significantly improve Crohn’s disease symptoms
October 23, 2018 - Knowledge of sex differences in lower urinary tract may help stimulate breakthroughs in diagnosis, management
October 23, 2018 - Common antibodies associated with myocardial infarction
October 23, 2018 - Study reveals new treatment option for women with advanced breast cancer resistant to hormone therapy
October 23, 2018 - Brain’s ‘Self-Control’ Center May Be Key to Weight-Loss Success
October 23, 2018 - Prosthetic valve mismatches common in transcatheter valve replacement, ups risk of death
October 23, 2018 - Can virtual reality help people become more compassionate?
October 23, 2018 - Screen time eclipsed outdoor time for most students, shows study
October 23, 2018 - SLU researcher seeks to find solutions for ‘chemo brain’ symptoms and side effects of opioids
October 23, 2018 - Plastics now commonly found in human stools
October 23, 2018 - Zoledronic acid increases disease-free survival in premenopausal women with HR+ early breast cancer
October 23, 2018 - Cancer survivors at risk for heart failure during, after pregnancy
October 23, 2018 - Stanford project brings health education videos to mothers in South Africa
October 23, 2018 - HIV-infected Hispanics at higher risk of developing HPV-related cancers, finds study
October 23, 2018 - Politicians hop aboard ‘Medicare-for-all’ train, destination unknown
October 23, 2018 - Study suggests rising childhood obesity rates as cause for serious hip disease in adolescents
October 23, 2018 - Study highlights existence of barriers to early clinical trial access for adolescents and young adults
October 23, 2018 - Protein sequencing technique could revolutionize biomedical research
October 23, 2018 - Canon Medical to showcase world’s first Ultra-High Resolution CT system at ASTRO 2018
October 23, 2018 - Spectrum Pharmaceuticals Announces Release of Updated Poziotinib Data From MD Anderson Phase 2 Study in Non-Small Cell Lung Cancer Patients
October 23, 2018 - Cancer stem cells use ‘normal’ genes in abnormal ways
October 23, 2018 - Bad Blood: A conversation with investigative reporter John Carreyrou | News Center
October 23, 2018 - As U.S. fertility rates collapse, finger-pointing and blame follow
October 23, 2018 - Researchers develop promising targeted strategy to treat chemo-resistant blood cancer
October 23, 2018 - Pilot clinical trial shows effectiveness of bioelectronic medicine device for lupus
October 23, 2018 - Genentech’s combination therapy improves outcome in patients with non-squamous non-small cell lung cancer
October 23, 2018 - 11th World Stroke Congress examines high stroke impact in low- and middle-income countries
October 22, 2018 - Breast cancer survival could be extended with two new drug combinations
October 22, 2018 - Researchers discover how acne-causing bacteria resist treatment
October 22, 2018 - Cancer trial shows treating the prostate with radiotherapy improves survival
October 22, 2018 - New hope for a drug to treat lymphedema symptoms
October 22, 2018 - Immune-Based Treatment Helps Fight Aggressive Breast Cancer, Study Finds
October 22, 2018 - Takeda announces positive Phase 3 ALTA-1L data in first-line therapy for advanced ALK+ NSCLC
October 22, 2018 - Paternal exercise has significant impact on child’s lifelong metabolic health
October 22, 2018 - Targeting specific genomic mutation in breast cancer improves survival
October 22, 2018 - Loss of tumor protein p53 helps cancer cells grow in hostile environment
October 22, 2018 - IDT to demonstrate CRISPR expertise at European-focused events
October 22, 2018 - Breathing through the nose improves memory consolidation
October 22, 2018 - Recreational Marijuana Now Legal in Canada
October 22, 2018 - Scientists reveal drumming helps schoolchildren diagnosed with autism
October 22, 2018 - A stage IV cancer patient discusses what it means to live well with serious illness
October 22, 2018 - In Kids with Autism, Short Questionnaire May Detect GI Disorders
October 22, 2018 - Innovative strategy opens up new avenue of treatment for anthrax infections
October 22, 2018 - Merck presents MK-1454 Phase 1 data for treatment of advanced solid tumors or lymphomas
October 22, 2018 - Aspirin may be effective in preventing blood clots after knee replacement
October 22, 2018 - Drug cocktail that increases lifespan discovered
October 22, 2018 - Gilead Sciences presents Phase 3 results of filgotinib in biologic-experienced rheumatoid arthritis at 2018 ACR/ARHP Annual Meeting
October 22, 2018 - Study shows potential positive impact of group prenatal care on birth outcomes
October 22, 2018 - Immunotherapy with pembrolizumab extends survival in metastatic or recurrent head and neck cancer
October 22, 2018 - Health Tip: Keep Ticks Away
October 22, 2018 - Obsessive-compulsive disorder – Genetics Home Reference
October 22, 2018 - Researchers find disrupted functional connectivity in cerebellum of adults with HF-ASD
October 22, 2018 - Deciphera presents Phase 1 clinical results of DCC-2618 in patients with gastrointestinal stromal tumors
October 22, 2018 - Combination of Opdivo and Yervoy shows four-year survival benefits in patients with advanced melanoma
October 22, 2018 - Overcoming bottlenecks in early drug discovery with the power of sound
October 22, 2018 - Scientists discover genes that contribute to ADHD development
October 22, 2018 - Incyte announces Phase 2 FIGHT-202 trial data in patients with cholangiocarcinoma
October 22, 2018 - FDA approves update to Rituxan label to include information on treatment of rare forms of vasculitis
October 22, 2018 - At-home biofeedback therapy effective in relieving difficult-to-treat constipation
Researchers shed light on role of striosomal neurons in reinforcement learning

Researchers shed light on role of striosomal neurons in reinforcement learning

image_pdfDownload PDFimage_print

A pleasant surprise or a nasty shock is likely to be a memorable experience. For instance, if you touch a hot oven, you very quickly learn not to do it again.

Learning by trial-and-error, which can yield positive or negative consequences, is known as reinforcement learning. Individuals can learn new behaviors in unfamiliar environments by exploring and memorizing sensory cues or actions that lead to good or bad outcomes.

Neuroscientists know that a part of the forebrain called the basal ganglia plays an important role in reinforcement learning. A major part of the basal ganglia, the striatum, is composed of a patchwork of two types of tissue: the striosome and the matrix. However, even though they were discovered three decades ago, the distinct roles that these regions play has remained a mystery.

Now, researchers from the Neural Computation Unit at the Okinawa Institute of Science and Technology Graduate University (OIST) have used the latest optical neural imaging technology to isolate and record the activity of the neurons in the striosome, shedding light on the role of striosomal neurons in reinforcement learning. Their work was recently published in the journal eNeuro.

Neuroscientists have long supposed that the neurons of the striosome are involved in predicting when the outcome of a stimulus will be positive, a process called reward prediction. This is because these neurons connect to neurons in the midbrain that produce an important signaling chemical called dopamine, which regulates reward-motivated behavior in the vertebrate brain.

“Reward prediction is important to our daily lives,” says Professor Kenji Doya, leader of the Neural Computation Unit, “for example, when you find your favorite dish on a display or a menu, you can get excited even before actually eating it and make a choice accordingly.”

The role of the striosomal neurons in reward prediction had not been confirmed because their organization in the brain makes it very difficult to distinguish them and record their activities. “The striosomal neurons comprise only 15% of the striatum and they are scattered mosaically within it, making it hard to isolate them,” explains Tomohiko Yoshizawa, OIST technician and first author of the paper.

The OIST researchers overcame this problem by using a special imaging technique and gene manipulation technology. They worked with transgenic mice which express specific genes only in the striosomal neurons. The genes code for calcium indicators which glow under fluorescent light when the neurons become active. Imaging a deep brain area like the striatum previously required removing a large portion of the brain above that area. However, by using a new endoscopic microscope developed by a spin-off company from Stanford University, which uses a thin glass rod as its lens, the researchers could record the activity of the striosomal neurons in a minimally invasive way. Using this imaging technique with the transgenic mice, they were able to observe striosomal neurons for long periods of time and to measure their activity while the mice performed specific tasks.

In these tasks, the researchers presented the mice with four different odors: banana, lemon, cinnamon and mint. Each odor was linked to a specific outcome — lots of water (a big reward), a little water (a small reward), an air puff to the face (a negative reward) or nothing. The mice started licking the water spout as they anticipated a water reward from specific odors, even before water was delivered.

The researchers showed that, as mice learned the task, the striosomal neurons fired more actively in response to odor cues associated with water rewards, meaning they were involved in anticipating the outcome of the stimulus. These activities were proportional to the expected consequence — anticipation of a larger reward triggered a greater response in the neuron.

By measuring the activities of striosomal neurons every day for several weeks, the researchers showed that these brain cells are most active in early stages of learning, after about one week, or during late stages, after about two weeks. This means that the predictive activities of striosomal neurons are learning-stage specific.

The striosomal neurons were also active when the water or air puff was actually presented. This means that, in addition to transmitting signals about expected rewards, they also transmit information about the actual rewards.

“We can learn a lot from studying mice because the mosaic design of the striosomes and the matrix is the same in both the mouse brain and the human brain,” says Yoshizawa.

Understanding the specific role of striosomal neurons could one day help researchers to diagnose and treat disorders caused by signaling problems in this region of the brain, such as Huntingdon’s disease.

Source:

https://www.oist.jp/news-center/news/2018/4/16/predicting-future-%E2%80%9Cstriosome%E2%80%9D-neurons-basal-ganglia-play-key-role

Tagged with:

About author

Related Articles