A longstanding goal in neuroscience has been to image membrane voltage across a population of individual neurons in an awake, behaving mammal. Here we describe a genetically encoded fluorescent ...voltage indicator, SomArchon, which exhibits millisecond response times and is compatible with optogenetic control, and which increases the sensitivity, signal-to-noise ratio, and number of neurons observable several-fold over previously published fully genetically encoded reagents
. Under conventional one-photon microscopy, SomArchon enables the routine population analysis of around 13 neurons at once, in multiple brain regions (cortex, hippocampus, and striatum) of head-fixed, awake, behaving mice. Using SomArchon, we detected both positive and negative responses of striatal neurons during movement, as previously reported by electrophysiology but not easily detected using modern calcium imaging techniques
, highlighting the power of voltage imaging to reveal bidirectional modulation. We also examined how spikes relate to the subthreshold theta oscillations of individual hippocampal neurons, with SomArchon showing that the spikes of individual neurons are more phase-locked to their own subthreshold theta oscillations than to local field potential theta oscillations. Thus, SomArchon reports both spikes and subthreshold voltage dynamics in awake, behaving mice.
Recent advancements in generative artificial intelligence, particularly using large language models (LLMs), are gaining increased public attention. We provide a perspective on the potential of LLMs ...to analyze enormous amounts of data from medical records and gain insights on specific topics in neurology. In addition, we explore use cases for LLMs, such as early diagnosis, supporting patient and caregivers, and acting as an assistant for clinicians. We point to the potential ethical and technical challenges raised by LLMs, such as concerns about privacy and data security, potential biases in the data for model training, and the need for careful validation of results. Researchers must consider these challenges and take steps to address them to ensure that their work is conducted in a safe and responsible manner. Despite these challenges, LLMs offer promising opportunities for improving care and treatment of various neurologic disorders
In a recent article from Cell Reports Medicine, Kwak et al. generate novel insights about subtyping cognitively impaired individuals based on structural imaging. Quantifying heterogeneity in ...Alzheimer’s disease via subtyping could help us harness new disease-modifying therapies and improve patient care by providing a more targeted approach.
Objective
This article investigates whether public officials exhibit “cognitive shirking” prior to announcing retirement by changing the way they communicate during their final term.
Method
I analyze ...monthly speeches made by members of the U.S. House between the 105th and 109th terms, and collect data on psychological indicators found to indicate changes in cognition. A mixed effect logistic regression examines whether these indicators increase the probability of retirement before the end of the term.
Results
The probability of retirement is amplified by increases in the level of cognitive inconsistency they display in public speeches.
Conclusion
Public officials, when deciding whether to retire from politics, display patterns of shifting priorities before and after making their retirement announcement. This suggests that representatives’ justifications for policy choices go through significant reorganization as the electoral connection is severed.
Striatal parvalbumin (PV) and cholinergic interneurons (CHIs) are poised to play major roles in behavior by coordinating the networks of medium spiny cells that relay motor output. However, the small ...numbers and scattered distribution of these cells have hindered direct assessment of their contribution to activity in networks of medium spiny neurons (MSNs) during behavior. Here, we build on recent improvements in single-cell calcium imaging combined with optogenetics to test the capacity of PVs and CHIs to affect MSN activity and behavior in mice engaged in voluntary locomotion. We find that PVs and CHIs have unique effects on MSN activity and dissociable roles in supporting movement. PV cells facilitate movement by refining the activation of MSN networks responsible for movement execution. CHIs, in contrast, synchronize activity within MSN networks to signal the end of a movement bout. These results provide new insights into the striatal network activity that supports movement.
Comparatively little is known about how new instrumental actions are encoded in the brain. Using whole-brain c-Fos mapping, we show that neural activity is increased in the anterior dorsolateral ...striatum (aDLS) of mice that successfully learn a new lever-press response to earn food rewards. Post-learning chemogenetic inhibition of aDLS disrupts consolidation of the new instrumental response. Similarly, post-learning infusion of the protein synthesis inhibitor anisomycin into the aDLS disrupts consolidation of the new response. Activity of D1 receptor-expressing medium spiny neurons (D1-MSNs) increases and D2-MSNs activity decreases in the aDLS during consolidation. Chemogenetic inhibition of D1-MSNs in aDLS disrupts the consolidation process whereas D2-MSN inhibition strengthens consolidation but blocks the expression of previously learned habit-like responses. These findings suggest that D1-MSNs in the aDLS encode new instrumental actions whereas D2-MSNs oppose this new learning and instead promote expression of habitual actions.
Testicular torsion is a known cause of morbidity in pediatric patients, but the burden in the adult population is poorly understood. We sought to determine the incidence of testicular torsion and ...risk factors for orchiectomy in a population encompassing all ages. A cohort analysis of 1625 males undergoing surgery for torsion was performed using the 2011 and 2012 Healthcare Cost and Utilization Project Nationwide Emergency Departments Sample. Patient and hospital factors were examined for association with orchiectomy vs. testicular salvage. The estimated yearly incidence of testicular torsion was 5.9 per 100,000 males ages 1-17 years and 1.3 per 100,000 males ≥18 years. Among those undergoing surgical intervention, orchiectomy was performed in 33.6%. The risk of orchiectomy was highest in patients 1-11 years of age and patients over 50 years of age (46.0% and 69.7% of patients, respectively). Orchiectomy was also associated with public insurance (Medicaid/Medicare) or self-pay as primary payer. While testicular torsion is less common in the adult population, the rate of orchiectomy is high. Those with disadvantaged payer status are also at increased risk for testicular loss.
Abstract
The star formation rate density (SFRD) history of the universe is well constrained up to redshift
z
∼ 2. At earlier cosmic epochs, the picture has been largely inferred from UV-selected ...galaxies (e.g., Lyman-break galaxies; LBGs). However, the inferred star formation rates of LBGs strongly depend on the assumed dust extinction correction, which is not well constrained at high
z
, while observations in the radio domain are not affected by this issue. In this work we measure the SFRD from a 1.4 GHz selected sample of ∼600 galaxies in the GOODS-N field up to redshift ∼3.5. We take into account the contribution of active galactic nuclei from the infrared-radio correlation. We measure the radio luminosity function, fitted with a modified Schechter function, and derive the SFRD. The cosmic SFRD shows an increase up to
z
∼ 2 and then an almost flat plateau up to
z
∼ 3.5. Our SFRD is in agreement with those from other far-IR/radio surveys and a factor 2 higher than those from LBG samples. We also estimate that galaxies lacking a counterpart in the HST/WFC3
H
-band (
H-
dark) make up ∼25% of the
ϕ
-integrated SFRD relative to the full sample at
z
∼ 3.2, and up to 58% relative to LBG samples.
This study sought to establish by expert review a consensus-based, focused ultrasound curriculum, consisting of a foundational set of focused ultrasound skills that all Canadian medical students ...would be expected to attain at the end of the medical school program.
An expert panel of 21 point-of-care ultrasound and educational leaders representing 15 of 17 (88%) Canadian medical schools was formed and participated in a modified Delphi consensus method. Experts anonymously rated 195 curricular elements on their appropriateness to include in a medical school curriculum using a 5-point Likert scale. The group defined consensus as 70% or more experts agreeing to include or exclude an element. We determined a priori that no more than 3 rounds of voting would be performed.
Of the 195 curricular elements considered in the first round of voting, the group reached consensus to include 78 and exclude 24. In the second round, consensus was reached to include 4 and exclude 63 elements. In our final round, with 1 additional item added to the survey, the group reached consensus to include an additional 3 and exclude 8 elements. A total of 85 curricular elements reached consensus to be included, with 95 to be excluded. Sixteen elements did not reach consensus to be included or excluded.
By expert opinion-based consensus, the Canadian Ultrasound Consensus for Undergraduate Medical Education Group recommends that 85 curricular elements be considered for inclusion for teaching in the Canadian medical school focused ultrasound curricula.
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