The early-onset Alzheimer's disease MRI signature: a replication and extension analysis in early-stage AD.

Early-onset Alzheimer's disease (EOAD) is less investigated than the more common late-onset Alzheimer's disease (LOAD) despite its more aggressive course. A cortical signature of EOAD was recently proposed and may facilitate EOAD investigation. Here, we aimed to validate this proposed MRI biomarker of EOAD neurodegeneration in an Appalachian clinical cohort.

Are Wearable Photoplethysmogram-Based Heart Rate Variability Measures Equivalent to Electrocardiogram? A Simulation Study.

Background: Traditional electrocardiography (ECG)-derived heart rate variability (HRV) and photoplethysmography (PPG)-derived "HRV" (termed PRV) have been reported interchangeably. Any potential dissociation between HRV and PRV could be due to the variability in pulse arrival time (PAT; time between heartbeat and peripheral pulse).

Objective: This study examined if PRV is equivalent to ECG-derived HRV and if PRV's innate error makes it a high-quality measurement separate from HRV.

Gray matter volume of functionally relevant primary motor cortex is causally related to learning a hand motor task.

Variability in brain structure is associated with the capacity for behavioral change. However, a causal link between specific brain areas and behavioral change (such as motor learning) has not been demonstrated. We hypothesized that greater gray matter volume of a primary motor cortex (M1) area active during a hand motor learning task is positively correlated with subsequent learning of the task, and that the disruption of this area blocks learning of the task.

Coverage of education and training of traumatic brain injury-induced growth hormone deficiency in US residency and fellowship programs: a cross-sectional study.

Background: Hypopituitarism, including growth hormone deficiency (GHD), is a common sequela of traumatic brain injury (TBI). This study explored the coverage of education and training of TBI-induced hypopituitarism in general and GHD in particular, in postgraduate program curricula to identify knowledge gaps and opportunities.

Methods: An online survey and qualitative interviews (focus groups) were conducted among endocrinology, neurology, and physiatry postgraduate program directors in the United States (US).

Disruption of rat deep cerebellar perineuronal net alters eyeblink conditioning and neuronal electrophysiology.

The perineuronal net (PNN) is a specialized type of extracellular matrix found in the central nervous system. The PNN forms on fast spiking neurons during postnatal development but the ontogeny of PNN development has yet to be elucidated. By studying the development and prevalence of the PNN in the juvenile and adult rat brain, we may be able to understand the PNN's role in development and learning and memory.