A5057156019- Neuroendocrine regulation and behavior
- Neuroscience of respiration and sleep
- Neuroscience and Neuropharmacology Research
- Circadian rhythm and melatonin
- Photoreceptor and optogenetics research
- Stress Responses and Cortisol
- Neuroinflammation and Neurodegeneration Mechanisms
- Regulation of Appetite and Obesity
- Renin-Angiotensin System Studies
- Sleep and Wakefulness Research
- Neuropeptides and Animal Physiology
- Nitric Oxide and Endothelin Effects
- Heart Rate Variability and Autonomic Control
- Neural dynamics and brain function
- Receptor Mechanisms and Signaling
- Ion channel regulation and function
- Biochemical effects in animals
- Memory and Neural Mechanisms
- Heme Oxygenase-1 and Carbon Monoxide
- Adipose Tissue and Metabolism
- Hypothalamic control of reproductive hormones
- Neonatal and fetal brain pathology
- Neurological Disease Mechanisms and Treatments
- Genetic Syndromes and Imprinting
- Adenosine and Purinergic Signaling
Georgia State University
2018-2025
Augusta University
2009-2019
Georgia Regents Medical Center
2013-2016
University of Nebraska Medical Center
2011-2016
Augusta University Health
2011-2013
Wright State University
2000-2011
Graduate School USA
1993-2011
Medical Care Development
2010
University of Cincinnati
2004-2009
Universidade de São Paulo
2004-2005
Angiotensin II–mediated vascular brain inflammation emerged as a novel pathophysiological mechanism in neurogenic hypertension. However, the precise underlying mechanisms and functional consequences relation to blood–brain barrier (BBB) integrity central angiotensin II actions mediating neurohumoral activation hypertension are poorly understood. Here, we aimed determine whether BBB permeability within critical hypothalamic stem regions involved regulation was altered during Using digital...
The arcuate nucleus (ARC) of the hypothalamus plays a key role in sensing metabolic feedback and regulating energy homeostasis. Recent studies revealed activation microglia mice with high‐fat diet (HFD)‐induced obesity (DIO), suggesting potential pathophysiological for inflammatory processes within hypothalamus. To further investigate causes molecular underpinnings such glial activation, we analyzed microglial activity wild‐type (WT), monogenic obese ob/ob (leptin deficient), db/db...
A growing number of studies support an important contribution astrocytes to neurovascular coupling, i.e., the phenomenon by which variations in neuronal activity trigger localized changes blood flow that serve match metabolic demands neurons. However, since both constriction and dilations have been observed brain parenchymal arterioles upon astrocyte stimulation, specific influences these cells on vasculature remain unclear. Using acute slices, we present evidence showing degree rat cortical...
Abstract Consuming a calorically dense diet stimulates microglial reactivity in the mediobasal hypothalamus (MBH) association with decreased number of appetite-curbing pro-opiomelanocortin (POMC) neurons; whether reduction POMC neuronal function is secondary to activation unclear. Here we show that hypercaloric diet-induced obese mice, persistently activated microglia MBH hypersecrete TNFα turn stimulate mitochondrial ATP production neurons, promoting fusion their neurites, and increasing...
ANG II is thought to increase sympathetic outflow by increasing oxidative stress and promoting local inflammation in the paraventricular nucleus (PVN) of hypothalamus. However, relative contributions drive remain poorly understood, underlying cellular molecular targets have yet be examined. has been shown enhance Toll-like receptor (TLR)4-mediated signaling on microglia. Thus, present study, we aimed determine whether II-mediated activation microglial TLR4 a key target initiating PVN. We...
Angiotensin II (AngII) is a key neuropeptide that acting within the brain hypothalamic paraventricular nucleus regulates neurohumoral outflow to circulation. Moreover, an exacerbated AngII action contributes activation in hypertension. Although effects involve changes neuronal activity, precise underlying mechanisms, cellular targets, and distribution of receptors remain largely unknown. Thus, whether direct actions on neurons, or it acts via intermediary cells, such as astrocytes, still...
Stress elicits neuroendocrine, autonomic, and behavioral responses that mitigate homeostatic imbalance ensure survival. However, chronic engagement of such promotes psychological, cardiovascular, metabolic impairments. In recent years, the renin-angiotensin system has emerged as a key mediator stress responding its related pathologies, but neuronal circuits orchestrate these interactions are not known. These studies combine use Cre-recombinase/loxP in mice with optogenetics to structurally...
Angiotensin II (AngII) is implicated in neuroinflammation, blood-brain barrier (BBB) disruption, and autonomic dysfunction hypertension. We have previously shown that exogenous AngII stimulates Toll-like receptor 4 (TLR4) via type 1 (AT1R), inducing activation of hypothalamic microglia ex vivo, AngII-AT1R signaling necessary for the loss BBB integrity spontaneously hypertensive rats (SHRs). Herein, we hypothesized microglial TLR4 AT1R interactions represent a crucial mechanistic link between...
Abstract The hypothalamic neuropeptide oxytocin (OT) exerts prominent analgesic effects via central and peripheral action. However, the precise pathways recruited by OT are largely elusive. Here we discovered a subset of neurons whose projections preferentially terminate on receptor (OTR)-expressing in ventrolateral periaqueductal gray (vlPAG). Using newly generated line transgenic rats (OTR-IRES-Cre), determined that most vlPAG OTR expressing cells targeted GABAergic. Ex vivo stimulation...
1. The cellular properties of pre-autonomic neurones in the hypothalamic paraventricular nucleus (PVN) were characterized by combining vivo retrograde tracing techniques, vitro patch-clamp recordings and three-dimensional reconstruction recorded adult slices. 2. results showed that PVN constitute a heterogeneous neuronal population. Based on morphological criteria, classified into three subgroups. Type A (52 %) located ventral parvocellular (PaV) subnucleus, an oblique orientation with...
The paraventricular nucleus (PVN) of the hypothalamus is a central site known to modulate sympathetic outflow. Excitatory and inhibitory neurotransmitters within PVN dictate final goal present study was examine role interaction between excitatory neurotransmitter glutamate GABA in regulation activity. In alpha-chloralose- urethane-anesthetized rats, microinjection N-methyl-D-aspartate (NMDA; 50, 100, 200 pmol) into produced dose-dependent increases renal nerve activity, blood pressure, heart...
To study modulatory actions of nitric oxide (NO) on GABAergic synaptic activity in hypothalamic magnocellular neurons the supraoptic nucleus (SON), vitro and vivo electrophysiological recordings were obtained from identified oxytocin vasopressin neurons. Whole cell patch-clamp immunochemically was assessed by measuring GABA(A) miniature inhibitory postsynaptic currents (mIPSCs). The NO donor precursor sodium nitroprusside (SNP) L-arginine, respectively, increased frequency amplitude mIPSCs...
We previously reported enhanced cerebrovascular remodeling and arteriogenesis in experimental type 2 diabetes. This study tested the hypotheses that 1) cerebral but not peripheral angiogenesis is increased a spatial manner 2) peroxynitrite orchestrates vascular endothelial growth factor (VEGF)-mediated brain Stereology of brain, eye, skeletal muscle microvasculature was evaluated control diabetic rats using three-dimensional images. Migration tube formation properties microvascular cells...
Basal and activity-dependent cerebral blood flow changes are coordinated by the action of critical processes, including autoregulation, endothelial-mediated signaling, neurovascular coupling. The goal our study was to determine whether astrocytes contribute regulation parenchymal arteriole (PA) tone in response hemodynamic stimuli (pressure/flow). Cortical PA vascular responses astrocytic Ca 2+ dynamics were measured using an vitro rat/mouse brain slice model perfused/pressurized PAs;...
Hypothalamic inflammation, involving microglia activation in the arcuate nucleus (ARC), is proposed as a novel underlying mechanism obesity, insulin and leptin resistance. However, whether activated affects ARC neuronal activity, consequently basal hormonal-induced food intake, unknown. We show that lipopolysaccharide, an agonist of toll-like receptor-4 (TLR4), which we found to be expressed microglia, inhibited firing activity majority orexigenic agouti gene-related protein/neuropeptide Y...
Abstract Background Cardiovascular diseases, including heart failure, are the most common cause of death globally. Recent studies support a high degree comorbidity between failure and cognitive mood disorders resulting in memory loss, depression, anxiety. While neuroinflammation hypothalamic paraventricular nucleus contributes to autonomic cardiovascular dysregulation mechanisms underlying this disease remain elusive. The goal study was quantitatively assess markers (glial morphology,...