Tag: Motor and impulse regulation

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Complete Connectome of Fruit Fly Central Nervous System Now Open-Source

A new study published in Nature titled, “Distributed control circuits across a brain-and-cord connectome”, describes a complete wiring diagram of all the connections between neurons in the central nervous system of an adult fruit fly for translational applications.

The work was completed by an international team led by multiple labs at Harvard Medical School (HMS) and Princeton University. The team has made the entire connectome accessible online to propel research into complex behaviors and other fundamentals of the nervous system. 

The fruit fly, Drosophila melanogaster, offers an effective model as they are easy to breed and maintain in the lab. Despite having a relatively simple nervous system made up of around 160,000 neurons, they exhibit complex behaviors such as navigation, social interaction, learning, and responding to sensory cues. 

To build the connectome, the team used electron microscopy to produce millions of images of neurons and neural connections. AI tools aligned the images into a cohesive 3D map. 

“It is really important to have a central nervous system connectome that is as complete as possible so we can link up the brain and body and start thinking about behavior holistically,” said Wei-Chung Allen Lee, PhD, associate professor of neurobiology at HMS and co-corresponding author on the study. 

The connectome shows how each neuron connects in the brain and nerve cord at the synapse level. While the map doesn’t span the fly’s entire body, the team used identifiable neurons and literature review to connect the central nervous system to neurons in appendages and sensory organs. 

The authors have already used the connectome to explore motor control. While a longstanding idea in neuroscience is for a centralized controller in the brain to make decisions about actions, the authors discovered that motor control in the fruit fly mostly occurs at a local level. For example, movement of a fly’s leg is primarily controlled by the neural circuits for that leg. The local circuits for one leg then communicates with other appendages to carry out complex coordinated movements, such as walking. 

“The brain and nerve cord connectomes are each useful on their own, but until you can bridge the two, it’s hard to understand how information moves between the brain and the body,” said co-first author Helen Yang, PhD, a research fellow in neurobiology at HMS. 

Looking ahead, the researchers plan to add more information to the connectome, including data describing neuropeptides, molecules that support neuron communication. Insights from the connectome may reveal fundamental principles about how nervous systems operate across species, including in humans. 

The post Complete Connectome of Fruit Fly Central Nervous System Now Open-Source appeared first on GEN – Genetic Engineering and Biotechnology News.

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Tics and OCD: Why Treatments Differ and Ways to Support Your Kids

by Dr. Christine Conelea and Dr. Adrienne Manbeck

Tics, compulsions, and obsessions are part of many people’s everyday lives. As clinicians and researchers at the University of Minnesota Tic and Compulsivity Lab (MnTiC), we see people living with different, unique combinations of these symptoms that can feel interconnected. There are some broad differences between tics, obsessions, and compulsions, but it’s important to note that they do overlap and that a person can have all of these things at the same time. Still, disentangling symptoms in order to provide effective treatment can sometimes be challenging. 

Tics and compulsions are similar in that they both involve movements that are repetitive and difficult for the person to control. Research has shown that overlapping genetic, neurological, and psychological factors contribute to both experiences. Because of this, some researchers and clinicians consider both tics and compulsions to be on the “obsessive-compulsive spectrum.” However, there are important differences in treatment and in how loved ones can provide support.

Behaviors

Tics are sudden, repetitive, involuntary movements or sounds that are usually very brief.   Common tics include rapid or hard eye blinking, facial scrunching, throat clearing or sniffing. In our studies, we have found that people with tics have an average of 8 tics per minute. 

Many individuals with tics experience an urge right before they tic. This urge can feel like tension, an itch or pressure that typically goes away after the tic occurs. Tics tend to   wax and wane over time. Compulsions are often more rule bound or rigid and are driven by a thought. Common compulsions include checking, counting, washing and reordering. They tend to be longer, smooth movements or sequences of movements. They’re linked to very specific situations, triggers, or thoughts to prevent something bad from happening or to relieve anxiety. Compulsions can also be done in one’s head–like reviewing a memory or providing yourself reassurance.

Why Treatments Differ

Although tic disorders and OCD sometimes look similar on the surface (repetitive movements can occur in both), they are different disorders. Subjectively speaking, tics can feel like a “body itch” while compulsions might feel like a “brain itch.” Though they may be very connected for some people, what works for one won’t necessarily work for the other. 

In general, we often take a less interventionist approach to tic disorders because tics may not be inherently harmful. On the other hand, because compulsions work to reinforce obsessive thoughts and provide escape from non-harmful but unpleasant feelings, we often intervene with OCD as soon as possible. As clinicians working with children and teens, we want to help kids learn to be brave, learn that they can tolerate distress associated with anxiety, and learn that OCD doesn’t get to make their decisions for them. 

Watchful Waiting

In general, OCD will not get better on its own. If a parent notices symptoms associated with distress or impairment, taking action of some kind is often the best approach. If tics aren’t causing problems for a child, it might be best to monitor. If tics become painful, start to bother your child, or in some other way cause harm, that might be the time to pursue treatment. The American Academy of Neurology refers to this as “watchful waiting” and sees it as an appropriate treatment, in some cases, for tics.

Tips for Providing Support

People with tic disorders face high stigma and discrimination compared to the general population. Tics are often hyper-visible and poorly understood. For OCD, stigma is more likely to emerge from public messaging rather than hypervisibility. The general public talks about OCD in a highly stereotyped way that misses a lot of people’s actual experiences with OCD and can trivialize symptoms. 

For both OCD and tic disorders, parents can help support their child by collaboratively developing a reward structure for hard work in therapy.

For tic disorders, research has shown that situational factors have an important role in influencing tics, including what a person is doing, who is around them, and how they are feeling. Most people can identify situational factors that make their tics better or worse. Some factors frequently associated with tic exacerbation are fatigue, social events, and starting school in the fall. Stress, frustration, or anxiety-provoking events can make it harder for the brain to inhibit tics. Events frequently reported to coincide with tic reductions include social interactions with familiar people, situations in which the individual is a passive participant or deeply focused on a task, and leisure activities. 

Because tics are so reactive to situational factors, one of the best ways to provide support is to create tic-neutral environments. This means eliminating intended or unintended consequences related to the tics, such as minimizing reactions to tics or changes to activities because of tics. We frame this as, “focusing on the person instead of the tics.” Tic neutrality can also help children feel better about tics since they can’t control them. 

For OCD, minimizing parent accommodation, or the things that parents do to help their kids avoid feeling anxious, can be helpful. Parents can help their kids by reducing accommodation and encouraging their children to be brave and face their fears in manageable, developmentally-appropriate ways.

About the Authors:

Christine Conelea, PhD is an Associate Professor in the Department of Psychiatry & Behavioral Sciences at the University of Minnesota, a licensed clinical psychologist, and the director of the MnTiC Lab. Dr. Conelea’s research interests include Tourette Syndrome/tic disorders, obsessive-compulsive disorder (OCD), and anxiety disorders. She is particularly interested in understanding how the brain, environment, and psychosocial factors interact to impact symptoms and treatment outcomes.

Adrienne Manbeck, PhD, is a postdoctoral fellow in the MnTiC Lab. Dr. Manbeck earned her doctorate in clinical psychology at the University of Minnesota and completed her pre-doctoral internship at Allegheny General Hospital in Pittsburgh, PA. Dr. Manbeck’s research aims to better understand the development, maintenance, and treatment of OCD and anxiety disorders across the lifespan, with a particular emphasis on the impact of societal stressors on these disorders, including the ways in which societal stressors impact symptom severity, access to high-quality treatment, and impact of treatment on symptoms.

More Reading:

Micali, N., Heyman, I., Perez, M., Hilton, K., Nakatani, E., Turner, C., & Mataix-Cols, D. (2010). Long-term outcomes of obsessive–compulsive disorder: Follow-up of 142 children and adolescents. British Journal of Psychiatry, 197(2), 128–134. 

Conelea, C.A., Woods, D.W., Zinner, S.H. et al. The Impact of Tourette Syndrome in Adults: Results from the Tourette Syndrome Impact Survey. Community Ment Health J 49, 110–120 (2013).

Tourette Association of America Tourette Awareness Month resources

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The post Tics and OCD: Why Treatments Differ and Ways to Support Your Kids appeared first on International OCD Foundation.

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Amelioration of tic disorder by Jujuboside A via gut microbiota remodeling and intestinal 5-HT signaling

BackgroundTic disorder (TD) is a common chronic neuropsychiatric condition manifesting during childhood and adolescence. Jujuboside A (JuA) may alleviate TD symptoms; however, the mechanisms underlying its therapeutic effects remain unclear.MethodsWe established a rat model of TD and used histological techniques to evaluate the effects of JuA on pathological changes. We also measured 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) levels and assessed tryptophan hydroxylase 1 (TPH1) mRNA expression. Finally, we analyzed the gut microbiota composition in fecal samples using 16S rRNA metagenomic sequencing.ResultsJuA administration alleviated pathological changes in rats with TD, increased 5-HT and 5-HIAA levels, and upregulated TPH1 mRNA expression. Compared with no treatment, JuA treatment increased the proportion of Bacteroidia, Muribaculaceae, Bacteroidales, and Bacteroidota, while reducing that of Bacilli, Lactobacillaceae, Lactobacillus, Lactobacillales, and Firmicutes.ConclusionThese findings indicate that JuA mitigates TD progression, potentially by remodeling the gut microbiota and regulating 5-HT levels.
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Multivariate age-related variations in quantitative MRI maps: widespread age-related differences revisited

This study applied multivariate ANOVA to investigate age-related microstructural changes in the brain tissues driven primarily by myelin, iron, and water content, as observed in MRI (semi-)quantitative R1, R2*, MTsat and PD maps. This is effectively a re-analysis of the data analyzed in a univariate way in a previous publication. Voxel-wise analyses were performed on gray matter (GM) and white matter (WM), in addition to region of interest (ROI) analyses. The multivariate approach identified brain regions showing coordinated alterations in multiple tissue properties and demonstrated bidirectional correlations between age and all examined modalities in various brain regions, including the caudate nucleus, putamen, insula, cerebellum, lingual gyri, hippocampus, and olfactory bulb. The multivariate model was more sensitive than univariate analyses, as evidenced by detecting a larger number of significant voxels within clusters in the supplementary motor area, frontal cortex, hippocampus, amygdala, occipital cortex, and cerebellum bilaterally. Though when cross validating the results by splitting the data into 2 subsets, sensitivity is strongly reduced, even more so for the multivariate approach. The examination of normalized, smoothed, and z-transformed maps within the ROIs revealed concurrent age-dependent alterations in myelin, iron, and water content. These findings contribute to our understanding of age-related brain differences and provide insights into the underlying mechanisms of aging. The study emphasizes the importance of multivariate analysis for detecting subtle microstructural changes associated with aging when dealing with multiple quantitative MRI parameter maps.
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ASGCT 2026: Beverly Davidson Offers Vehicle and Route for Huntington’s Disease Gene Therapy

BOSTON – Geneticist Beverly Davidson, PhD, received the 2026 Outstanding Achievement Award from the American Society of Gene and Cell Therapy (ASGCT). Davidson is currently the chief scientific strategy officer at the Children’s Hospital of Philadelphia (CHOP) and a former president of ASGCT.

Some of the research Davidson presented was conducted at a new biotech company she co-founded called Latus Bio, which earlier this month announced it had raised $97 million in a Series A round. The company develops novel AAVs to specifically target central nervous system (CNS) disorders, with a lead program in Huntington’s disease (HD).

After thanking her mentors—Bill Kelly, MD, Michael Welsh, MD, and Kathy High, MD—Davidson turned her attention to presenting new advances in engineered gene therapies. Throughout her career, she has focused on improving adeno-associated viruses (AAVs) for CNS gene therapies, with a particular emphasis now on HD. Key elements include selecting the right cargo and developing the appropriate delivery vehicle. Her goal is to scale lab research in neurons, mouse models, and non-human primates (NHPs) to treat patients, including adults with HD.

Major hurdles to tackling genetic diseases of the brain include scalability and a lack of potency, Davidson said. The search for alternative AAV serotypes to AAV2 that could target neuronal cells began back in 2000. IV administration does not provide sufficient targeting to the brain. Even AAVs that have been engineered to enter the brain from the blood have high peripheral exposure and a high cost of goods per patient, which significantly lowers scalability and impact. (In one study, liver biodistribution of AAV was many orders of magnitude higher than in the CNS.)

Davidson focused on HD, the late-onset, dominantly inherited genetic disease. The identification of the gene harboring the HD mutation in the early 1990s by a consortium of researchers was one of the biggest success stories in human genetics. Even more remarkable was the underlying disease mechanism—the expansion in exon 1 of the gene of a triplet repeat sequence (CAG) producing an abnormally long string of glutamine residues in the huntingtin protein.

The right target

One of the major challenges in devising a gene therapy for HD is ensuring that the therapeutic reaches the right network—the deep brain and cortical areas. Therapies have to reach the right circuit, and the right cells in those circuits, Davidson said. Over the years, her group has tailored AAVs for delivery to the brain, inserting peptides into exposed loops of the virion to allow for targeting and unbiased diversity for blood-to-brain delivery. Nowadays, she said, machine learning approaches can be applied for further capsid improvements.

Davidson’s CHOP lab developed a method for screening AAVs with enhanced potency for CNS therapies. After generating huge libraries containing tens of millions of novel capsids, the group performed serial enrichments to identify the most attractive capsids. After screening pools of injected capsids into two species of monkeys, a winning capsid emerged: AAV-DB-3.

Davidson’s group infused AAV-DB-3 into NHPs, looking for targeting to the putamen (base of the forebrain) and caudate regions. Those results were published in Nature Communications in 2025.  “AAV-DB-3 really stood out for its ability to transduce deep layer cortical neurons that are important” in HD, Davidson said. Moreover, the results were achieved with relatively low doses and only required a single infusion per hemisphere, outperforming the widely used AAV5.

Somatic instability

With a promising delivery vehicle identified, Davidson next addressed the therapeutic strategy, which takes aim at the somatic expansion of the CAG repeat. This codon grows longer over time in certain cells in the brain, sometimes expanding to hundreds of repeats.

MSH3 is a DNA repair protein that is required for CAG repeat expansions, as seen in mouse models of HD and other triplet repeat disorders, including myotonic dystrophy. Research led by Paul Ranum, PhD, who is a co-founder of Latus Bio, posted in a preprint on bioRxiv earlier this year, modeled the impact of lowering levels of MSH3 on somatic instability.

Ranum and colleagues used an artificial microRNA showed to lower MSH3 levels in NHPs by 48-94 percent. Computational modeling suggests that this would reduce somatic instability and delay onset of HD symptoms by many years. Early studies using a well-known HD mouse model, the Q111 mouse, to assess biodistribution, quantify knockdowns, and assess the impact on somatic CAG repeat expansion. AAV-DB-3 expression is highest in the striatum and cortex at 16 weeks, dropping MSH3 levels by 50%.

Davidson closed by emphasizing the need to ensure scalability for treatment beyond ultra-rare disorders. Latus hopes to file an Investigational New Drug application for its HD therapy, LTS-201, in the second half of 2026. At least two other biotech companies are also targeting MSH3 by other means.

 

 

The post ASGCT 2026: Beverly Davidson Offers Vehicle and Route for Huntington’s Disease Gene Therapy appeared first on GEN – Genetic Engineering and Biotechnology News.

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1H-MRS brain metabolites as biomarkers of high-altitude hypobaric hypoxia following mild traumatic brain injury in mice

Introduction and objectivePopulations at high altitude (HA) face a higher incidence and severity of traumatic brain injury (TBI). This pilot study utilized longitudinal 1H-MRS to identify neurochemical biomarkers of HA adaptation and the subsequent metabolic response to mild TBI (mTBI).MethodsMale C57BL/6J mice were exposed to simulated HA (5,000 m) or sea level (SL) for 12 weeks. Following adaptation, a unilateral mTBI was induced via closed head injury (CHI). Mice were then monitored for an additional 2 weeks at HA (total duration of 14 weeks). In vivo1H-MRS spectra (7 T) were collected from the frontal cortex, hippocampi, and cerebellum at weeks 0, 4, 12 to assess HA adaptation. Following the CHI, subsequent measurements were collected at week 12 (post-injury) and week 14 to monitor longitudinal neurochemical responses to the mTBI.ResultsChronic HA exposure induced significant reductions in myo-inositol (Ins) and total choline (tCho) in the hippocampus, establishing a baseline of metabolic fragility that sensitized the brain to subsequent traumatic insult. Post-mTBI, the HA group exhibited a profound “metabolic crisis,” characterized by significantly lower tCho and failed recovery of total N-acetylaspartate (tNAA) compared to SL controls. Total creatine (tCr) was the most acutely affected metabolite, underscoring a depletion of the bioenergetic reserve.ConclusionChronic hypobaric hypoxia fundamentally alters baseline brain metabolism and impairs the neurochemical recovery from mTBI. These findings suggest that standard recovery protocols may be insufficient for HA-adapted populations and highlight 1H-MRS as a critical tool for detecting “invisible” metabolic vulnerability in extreme environments.
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Targeted Ultrasound Could Offer Alternative to Chronic Pain Medication

A new study has shown that targeting ultrasound stimulation to brain regions involved in processing pain can induce long-lasting changes in brain activity, significantly reducing pain perception. Published in Nature Communications, these findings point at a novel non-invasive strategy to treat chronic pain. 

“Our study represents an important first step in understanding how this technology can non-invasively stimulate deep brain regions involved in pain processing,” said Sam Hughes, PhD, senior lecturer in pain neuroscience at the University of Exeter. “We found that targeting a specific brain region involved in pain processing can alter how pain is perceived and change how this area communicates with other parts of the brain’s pain network. The next stage of our research will be to test whether this approach can help people living with chronic pain.”

Hughes and colleagues used transcranial ultrasound stimulation (TUS), a low-intensity neuromodulation technique, to target the dorsal anterior cingulate cortex (dACC), a brain region implicated in chronic pain. The study recruited a total of 32 healthy volunteers, who were treated either with TUS or a sham while putting their right hand in a cold gel to trigger pain due to the low temperature. All participants were asked to rate the severity of the pain they were feeling and underwent MRI and MRS scans to monitor the physiological changes caused by the treatment. 

Results showed that, while TUS had no immediate effect on pain intensity, participants reported a significant reduction in pain from 28 to 55 minutes after the stimulation, suggesting it can trigger a delayed analgesic effect. At the physiological level, TUS was found to disrupt the relationship between temperature and pain intensity, increasing the connectivity between the dACC and other brain regions involved in pain modulation and changing the concentration of the GABA neurotransmitter within the dCC. 

“The study aimed to characterize how transcranial ultrasound stimulation interacts with—and potentially also alters—the brain’s processing of pain,” said Sophie Clarke, PhD, postdoctoral research fellow at the University of Plymouth and lead author of the study. “Understanding these mechanisms will be very important to support the next steps in understanding whether the stimulation can be effective in helping patients with chronic pain.”

Previous research at the University of Plymouth had shown the potential benefits of TUS for psychiatric conditions including anxiety, depression, and addiction. This study shows these benefits could extend beyond neurological disorders and one day offer a non-invasive treatment option for those experiencing chronic pain due to conditions such as fibromyalgia, back pain, and arthritis, or recovering after cancer treatment.  

“Having shown the use of ultrasound can yield positive results for people with a variety of neurological conditions, we wanted to explore what it could mean for those living with chronic pain,” said Elsa Fouragnan, PhD, director of the University of Plymouth’s Brain Research and Imaging Centre (BRIC) and Centre for Therapeutic Ultrasound (CENTUS). “Most of us know someone experiencing chronic pain, and there are very few treatments that deliver any form of long-term benefit. The findings of this new work are really promising, and we are already building on it to assess whether TUS could be a beneficial and non-invasive therapeutic treatment.”

The post Targeted Ultrasound Could Offer Alternative to Chronic Pain Medication appeared first on Inside Precision Medicine.

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Direct modulation of human GABA-A α1β2γ2 receptors by the endocannabinoid 2-arachidonoylglycerol: implications for cannabinoid-related ligands and limitations for anxiolytic drug development

Anxiety disorders are associated with impaired inhibitory neurotransmission mediated by γ-aminobutyric acid type A (GABA-A) receptors. Although benzodiazepines remain effective anxiolytics, their clinical utility is limited by sedation, cognitive impairment, tolerance, and dependence, prompting the search for mechanistically distinct GABAergic modulators. Among cannabinoid-related molecules, the strongest evidence for direct GABA-A receptor modulation concerns the endocannabinoid 2-arachidonoylglycerol (2-AG), which potentiates recombinant human α1β2γ2 receptors through residues located in the M4 helix of the β2 subunit. Here, we review the structural architecture, biophysical properties, and pharmacological profile of the human GABA-A α1β2γ2 isoform as the relevant molecular framework for evaluating this mechanism, while discussing the broader relevance of cannabinoid-related ligands and selected phytocannabinoids without assuming mechanistic equivalence. We further assess the hypothesis that 2-AG reaches the β2-M4 site through a membrane-access route and identify five conceptual barriers that currently limit translation of this mechanism into anxiolytic drug development: supraphysiological effective concentrations, unresolved synaptic-versus-extrasynaptic actions, uncertain subtype selectivity, incomplete validation of lipid-environment effects, and lack of clinical evidence linking this mechanism to anxiolysis in humans. We conclude that direct modulation through β2-M4 defines a mechanistically intriguing allosteric pathway distinct from benzodiazepine action; however, its location on a shared β2 subunit and the micromolar concentrations required for modulation represent substantial obstacles to the rational design of anxioselective agents based on this mechanism.