Publications by authors named "Audrey Hildebrandt"

Hippocampal sclerosis (HS) is associated with advanced age as well as transactive response DNA-binding protein with 43 kDa (TDP-43) deposits. Both hippocampal sclerosis and TDP-43 proteinopathy have also been described in chronic traumatic encephalopathy (CTE), a neurodegenerative disease linked to exposure to repetitive head impacts (RHI). However, the prevalence of HS in CTE, the pattern of TDP-43 pathology, and associations of HS and TDP-43 with RHI are unknown.

View Article and Find Full Text PDF

Background And Purpose: The purpose was to explore the effects of transcutaneous trigeminal nerve stimulation (TNS) on neurochemical concentrations (brainstem, anterior cingulate cortex [ACC], dorsolateral prefrontal cortex [DLPFC], ventromedial prefrontal cortex [VMPFC], and the posterior cingulate cortex [PCC]) using ultrahigh-field magnetic resonance spectroscopy.

Methods: This double-blinded study tested 32 healthy males (age: 25.4 ± 7.

View Article and Find Full Text PDF

Objective: Transcutaneous auricular vagal nerve stimulation (taVNS) may benefit cognition in healthy adults but may differentially affect specific domains of cognitive function. Currently, optimal stimulation parameters of taVNS have yet to be identified and the overall effectiveness of this approach remains unclear.

Method: A literature review and random effects meta-analysis evaluated the effects of taVNS on cognitive performance outcomes across domains of function and outcome metrics (accuracy and response times).

View Article and Find Full Text PDF

Background Gadolinium retention after repeated gadolinium-based contrast agent (GBCA) exposure has been reported in subcortical gray matter. However, gadolinium retention in the cerebral cortex has not been systematically investigated. Purpose To determine whether and where gadolinium is retained in rat and human cerebral cortex.

View Article and Find Full Text PDF

The inflammatory system has been implicated in the pathophysiology of a variety of psychiatric conditions. Individuals with PTSD, depression, and other fear- and anxiety-related disorders exhibit alterations in peripheral circulating inflammatory markers, suggesting dysregulation of the inflammatory system. The relationship between inflammation and PTSD has been investigated almost exclusively in the periphery, and has not been extensively explored in human postmortem brain tissue.

View Article and Find Full Text PDF

The mechanisms underpinning concussion, traumatic brain injury, and chronic traumatic encephalopathy, and the relationships between these disorders, are poorly understood. We examined post-mortem brains from teenage athletes in the acute-subacute period after mild closed-head impact injury and found astrocytosis, myelinated axonopathy, microvascular injury, perivascular neuroinflammation, and phosphorylated tau protein pathology. To investigate causal mechanisms, we developed a mouse model of lateral closed-head impact injury that uses momentum transfer to induce traumatic head acceleration.

View Article and Find Full Text PDF

Cellular adaptations to endurance training are influenced by the intensity and duration of exercise. To examine the impact of exercise intensity and duration on the acute transcriptional regulation of metabolic genes in red (RG) and white (WG) gastrocnemius muscle, rats completed either low-intensity [ approximately 50% maximal O2 uptake (VO2 max)] treadmill exercise (LIE) for 45 min, LIE for 180 min, or high-intensity ( approximately 75% VO2 max) exercise (HIE) for 45 min. LIE for 45 min activated (P < 0.

View Article and Find Full Text PDF

The serine/threonine kinase Akt/PKB plays key roles in the regulation of cell growth, survival, and metabolism. It remains unclear, however, whether the functions of individual Akt/PKB isoforms are distinct. To investigate the function of Akt2/PKBbeta, mice lacking this isoform were generated.

View Article and Find Full Text PDF

We determined the effect of a cannabinoid CB1 receptor antagonist (AM-251; N-(Piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide) on food intake, body weight and adipose tissue mass in Western diet-induced obese (DIO) mice using a chronic, interrupted, oral dosing paradigm. The dosing paradigm was 2 weeks on treatment (treatment 1), 2 weeks off-treatment, followed by 2 weeks on treatment (treatment 2). During treatment 1 and treatment 2, food intake and body weight were reduced after a single dose.

View Article and Find Full Text PDF

Introduction: Obesity is a significant public health concern with considerable academic and industrial research effort underway to discover novel drugs to treat this disease. The aim of this study was to validate a recently developed high-resolution X-ray computed tomography (micro CT) system capable of measuring murine adipose tissue depot mass in situ.

Methods: The micro CT was used to generate a series of cross-sectional X-ray images from which individual adipose tissue depot mass was quantified.

View Article and Find Full Text PDF

AMP-activated protein kinase (AMPK) has recently emerged as a key signaling protein in skeletal muscle, coordinating the activation of both glucose and fatty acid metabolism in response to increased cellular energy demand. To determine whether AMPK signaling may also regulate gene transcription in muscle, rats were given a single subcutaneous injection (1 mg/g) of the AMP analog 5-aminoimidazole-4-carboxamide-1-beta-d-ribonucleoside (AICAR). AICAR injection activated (P < 0.

View Article and Find Full Text PDF