hit counter

Prior Cocaine Use Disrupts Orbitofrontal Hidden-State Coding

MHD featured image for Prior Cocaine Use Disrupts Orbitofrontal Hidden-State Coding.

A 2026 eLife study recorded 3,881 lateral orbitofrontal cortex units in rats and found that prior cocaine use made the OFC over-distinguish task positions that controls treated as functionally equivalent. The headline result was not gross task failure: cocaine-experienced rats still performed the odor task, but their OFC ensembles showed higher S1-vs.-S2 decoding than sucrose …

Read more

Friedreich Ataxia MRI Study Finds 3 Progression Subtypes

Photoreal illustration of brain regions affected in Friedreich ataxia with overlay of MRI imaging modalities, conveying multi-pattern subtypes.

A 2026 longitudinal MRI preprint involving 54 people with Friedreich ataxia and 57 controls found 3 biologically interpretable progression subtypes: microstructure-dominant, macrostructure-dominant, and minimal/no progression.1 The clusters make biomarker heterogeneity visible at the research level, while the classifier remains too early to assign individual patients to treatment paths. Research Highlights 3 MRI progression subtypes emerged: …

Read more

Migrant Stroke Patients Had 1.90x Higher Late-Arrival Odds

Photoreal illustration of a stroke patient in an emergency room with overlay of treatment-eligibility imagery, conveying disparities in acute-stroke care.

A 2026 Dutch stroke-center cohort found the opposite of the damaged draft’s claim: patients with a migration background were more likely to reach the hospital outside the therapeutic window for acute reperfusion therapy, and they had sharply lower odds of receiving endovascular thrombectomy.1 Research Highlights Late arrival was the clearest disparity: 53.2% of migrant-background patients …

Read more

Anxious Depression fMRI Meta-Analysis Finds Left Temporal Activation

Editorial brain-map card for anxious depression with highlighted limbic and prefrontal regions from an earlier draft framing.

A 2026 fMRI meta-analysis of 11 studies found a narrow anxious-depression signal: 829 anxious-depression patients differed from 681 non-anxious MDD patients in left middle temporal gyrus activation (SDM-Z = 2.046, p = 0.020), while healthy-control contrasts centered on the anterior commissure and right middle frontal gyrus. The calibrated interpretation is not “amygdala and insula hyperactivity …

Read more

Dexamethasone Disrupts Mouse Sleep Through Orexin Hyperarousal

Photoreal illustration of a steroid pill bottle with overlay of disrupted sleep architecture, conveying glucocorticoid-induced insomnia mechanism.

A 2026 male-mouse study found that 30 mg/kg dexamethasone for 5 days increased light-phase wakefulness (t13 = 4.122, p = 0.0012), decreased NREM sleep (t13 = 4.412, p = 0.0007), and amplified orexin-neuron activity during NREM-to-wake transitions (F1,9 = 6.941, p = 0.0272). The result points to orexin-linked hyperarousal as a testable explanation for steroid-induced …

Read more

Astrocyte Calcium Signals Shape Amygdala Fear Memory and Extinction in Mice

Photoreal illustration of astrocytes interacting with neurons in the amygdala, conveying glial role in fear circuit dynamics.

A 2026 Nature mouse study found that basolateral amygdala astrocyte Ca2+ signals tracked fear retrieval and extinction, then showed causality: 3 mg/kg CNO manipulations of astrocyte DREADDs pushed early-extinction freezing in opposite directions while both disrupting later extinction retrieval.1 Research Highlights Astrocytes tracked fear state: after 3 tone-shock pairings and 2 days of 25 cue-only …

Read more

MS Memory Loss: 7-Day Recall Finds What 30-Minute Tests Miss

Photoreal illustration representing memory and forgetting in multiple sclerosis, with imagery of a fading word list and brain consolidation pathways.

Standard memory testing can tell a multiple-sclerosis (MS) patient that recall is normal after 30 minutes while missing a deficit that appears days later. Jansen et al. tested that exact blind spot in 62 MS patients and 65 matched controls: 7-day/30-minute recall ratios were lower in MS on both verbal-list recall (0.64 vs. 0.78, p …

Read more