Publications by authors named "Mark Rossi"

Objective: Although glucagon-like peptide 1 (GLP-1) is known to regulate feeding, the central mechanisms contributing to this function remain enigmatic. Here, we aim to test the role of neurons expressing GLP-1 receptors (GLP-1R) in the dorsolateral septum (dLS; dLS) that project to the lateral hypothalamic area (LHA) on food intake and determine the relationship with feeding regulation.

Methods: Using chemogenetic manipulations, we assessed how activation or inhibition of dLS neurons affected food intake in Glp1r-ires-Cre mice.

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Objective: Although glucagon-like peptide 1 (GLP-1) is known to regulate feeding, the central mechanisms contributing to this function remain enigmatic. Here, we aim to test the role of neurons expressing GLP-1 receptors (GLP-1R) in the dorsolateral septum (dLS; dLS ) and their downstream projections on food intake and determine the relationship with feeding regulation.

Methods: Using chemogenetic manipulations, we assessed how activation or inhibition of dLS neurons affected food intake in mice.

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Central nervous system (CNS) control of metabolism plays a pivotal role in maintaining energy homeostasis. Glucagon-like peptide-1 (GLP-1, encoded by ), secreted by a distinct population of neurons located within the nucleus tractus solitarius (NTS), suppresses feeding through projections to multiple brain targets. Although GLP-1 analogs are proven clinically effective in treating type 2 diabetes and obesity, the mechanisms of GLP-1 action within the brain remain unclear.

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The brain has long been known to control stress and reward through complex and interconnected circuitry. A new study now reveals a group of hypothalamic neurons that paradoxically mediate both reward and aversion.

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The lateral hypothalamic area (LHA) is a subcortical brain region that exerts control over motivated behavior, feeding, and energy balance across species. Recent single-cell sequencing studies have defined at least 30 distinct LHA neuron types. Some of these influence specific aspects of energy homeostasis; however, the functions of many LHA cell types remain unclear.

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Objective: Maternal overnutrition is associated with adverse outcomes in offspring, including increased risk for obesity and diabetes. Here, we aim to test the effects of maternal obesity on lateral hypothalamic feeding circuit function and determine the relationship with body weight regulation.

Methods: Using a mouse model of maternal obesity, we assessed how perinatal overnutrition affected food intake and body weight regulation in adult offspring.

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Background: Hazard identification, risk assessment, regulatory, and policy activity are usually conducted on a chemical-by-chemical basis. Grouping chemicals into categories or classes is an underutilized approach that could make risk assessment and management of chemicals more efficient for regulators.

Objective And Methods: While there are some available methods and regulatory frameworks that include the grouping of chemicals (e.

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The manufacture and production of industrial chemicals continues to increase, with hundreds of thousands of chemicals and chemical mixtures used worldwide, leading to widespread population exposures and resultant health impacts. Low-wealth communities and communities of color often bear disproportionate burdens of exposure and impact; all compounded by regulatory delays to the detriment of public health. Multiple authoritative bodies and scientific consensus groups have called for actions to prevent harmful exposures via improved policy approaches.

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An acid-secreting stomach provides many selective advantages to fish and other vertebrates; however, phenotypic stomach loss has occurred independently multiple times and is linked to loss of expression of both the gastric proton pump and the protease pepsin. Reasons underpinning stomach loss remain uncertain. Understanding the importance of gastric acid-secretion to the metabolic costs of digestion and growth will provide information about the metabolic expense of acid-production and performance.

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Unilateral dopamine (DA) depletion produces ipsiversive turning behaviour, and the injection of DA receptor agonists can produce contraversive turning, but the underlying mechanisms remain unclear. We conducted in vivo recording and pharmacological and optogenetic manipulations to study the role of DA and striatal output in turning behaviour. We used a video-based tracking programme while recording single unit activity in both putative medium spiny projection neurons (MSNs) and fast-spiking interneurons (FSIs) in the dorsal striatum bilaterally.

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Purpose: Employment status is considered a determinant of health, yet returning to work is frequently a challenge after lower limb amputation. No studies have documented if working after lower limb amputation is associated with functional recovery. The study's purpose was to examine the influence of full-time employment on functioning after lower limb amputation.

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µ-Opioid peptide receptor (MOPR) stimulation alters respiration, analgesia and reward behaviour, and can induce substance abuse and overdose. Despite its evident importance, the endogenous mechanisms for MOPR regulation of consummatory behaviour have remained unknown. Here we report that endogenous MOPR regulation of reward consumption in mice acts through a specific dorsal raphe to nucleus accumbens projection.

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The lateral hypothalamic area (LHA) regulates feeding- and reward-related behavior, but because of its molecular and anatomical heterogeneity, the functions of defined neuronal populations are largely unclear. Glutamatergic neurons within the LHA (LHA) negatively regulate feeding and appetitive behavior. However, this population comprises transcriptionally distinct and functionally diverse neurons that project to diverse brain regions, including the lateral habenula (LHb) and ventral tegmental area (VTA).

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Choice behavior is characterized by temporal discounting, i.e., preference for immediate rewards given a choice between immediate and delayed rewards.

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The habenula complex is appreciated as a critical regulator of motivated and pathological behavioral states via its output to midbrain nuclei. Despite this, transcriptional definition of cell populations that comprise both the medial habenular (MHb) and lateral habenular (LHb) subregions in mammals remain undefined. To resolve this, we performed single-cell transcriptional profiling and highly multiplexed in situ hybridization experiments of the mouse habenula complex in naive mice and those exposed to an acute aversive stimulus.

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Oxytocin (OT) is critical for the expression of social behavior across a wide array of species; however, the role of this system in the encoding of socially relevant information is not well understood. In the present study, we show that chemogenetic activation of OT neurons within the paraventricular nucleus of the hypothalamus (PVH) of male mice (OT-Ires-Cre) enhanced social investigation during a social choice test, while chemogenetic inhibition of these neurons abolished typical social preferences. These data suggest that activation of the OT system is necessary to direct behavior preferentially toward social stimuli.

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The current obesity epidemic is a major worldwide health concern. Despite the consensus that the brain regulates energy homeostasis, the neural adaptations governing obesity are unknown. Using a combination of high-throughput single-cell RNA sequencing and longitudinal in vivo two-photon calcium imaging, we surveyed functional alterations of the lateral hypothalamic area (LHA)-a highly conserved brain region that orchestrates feeding-in a mouse model of obesity.

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Objective: To determine whether any strength, range of motion (ROM), or functional improvement exists in the adductor canal block (ACB) group after completion of inpatient rehabilitation and following the removal of the continuous block.

Design: Retrospective cohort.

Setting: Inpatient rehabilitation at discharge and outpatient orthopedic clinic for follow-up.

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Central regulation of food intake is a key mechanism contributing to energy homeostasis. Many neural circuits that are thought to orchestrate feeding behavior overlap with the brain's reward circuitry both anatomically and functionally. Manipulation of numerous neural pathways can simultaneously influence food intake and reward.

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Genetic defects in the synaptic scaffolding protein gene, SHANK2, are linked to a variety of neuropsychiatric disorders, including autism spectrum disorders, schizophrenia, intellectual disability, and bipolar disorder, but the molecular mechanisms underlying the pleotropic effects of SHANK2 mutations are poorly understood. We generated and characterized a line of Shank2 mutant mice by deleting exon 24 (Δe24). Shank2Δe24-/- mice engage in significantly increased locomotor activity, display abnormal reward-seeking behavior, are anhedonic, have perturbations in circadian rhythms, and show deficits in social and cognitive behaviors.

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Background: Maintenance of the native patellar thickness has been deemed important for proper clinical outcomes after total knee arthroplasty (TKA). Our objective was to study the effects of the change in patellar thickness on patient-perceived outcomes (PPOs) after TKA. We hypothesized that reestablishing native patellar thickness after TKA results in better PPOs.

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Background: It is important to understand the long-term consequences of postponing total joint arthroplasty until the onset of severe functional impairment. Therefore, the purpose of this investigation was to determine and compare the midterm to long-term postoperative outcomes of patients who underwent total joint arthroplasty with severe vs less severe preoperative functional impairment.

Methods: A total of 105 primary unilateral total hip/knee arthroplasty patients were studied.

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Alternatives analysis (AA) is a method used in regulation and product design to identify, assess, and evaluate the safety and viability of potential substitutes for hazardous chemicals. It requires toxicological data for the existing chemical and potential alternatives. Predictive toxicology uses in silico and in vitro approaches, computational models, and other tools to expedite toxicological data generation in a more cost-effective manner than traditional approaches.

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The prefrontal cortex is a critical neuroanatomical hub for controlling motivated behaviours across mammalian species. In addition to intra-cortical connectivity, prefrontal projection neurons innervate subcortical structures that contribute to reward-seeking behaviours, such as the ventral striatum and midline thalamus. While connectivity among these structures contributes to appetitive behaviours, how projection-specific prefrontal neurons encode reward-relevant information to guide reward seeking is unknown.

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