About

Melissa Lewis is associated with the College of Veterinary Medicine at NC State University, where she is involved in student engagement and support. She serves as the Director of Student Engagement, focusing on enriching the student experience through fostering a caring, collaborative culture and providing opportunities for personal and professional growth. Her role includes overseeing programs that support student achievement, well-being, and extracurricular development, including study abroad opportunities, research projects, and community building activities. Her work emphasizes creating an inclusive environment that encourages inquiry, empathy, and ethical practice among veterinary students.

Research topics

• Medicine
• Biology
• Surgery
• Internal medicine
• Nuclear medicine
• Statistics
• Animal science
• Mathematics
• Pathology
• Intensive care medicine
• Physical therapy
• Anesthesia
• Psychiatry
• Anatomy
• Radiology
• Physical medicine and rehabilitation

Selected publications

• Sex-specific role of the 5-HT2A receptor in psilocybin-induced extinction of opioid reward

  Nature Communications · 2025-11-20 · 6 citations

  articleOpen access

  R. Notably, female frontal cortex and NAc show fewer changes at gene enhancer regions in response to PSI, repeated OXY, or combined PSI-OXY treatment compared to males, with the frontal cortex exhibiting more pronounced sex differences than the NAc at the epigenomic level. Together, these results provide new insights into the neural and epigenetic mechanisms of psychedelic-induced plasticity in OUD, while also highlighting sex differences in PSI's modulation of reward pathways and its therapeutic potential.

  PublisherDOI

• Case Report: 3D-CISS and PC-MRI in the diagnosis and surgical planning of hydrocephalus secondary to presumptive lateral aperture obstruction in a dog

  Frontiers in Veterinary Science · 2025-10-10

  articleOpen access

  Introduction: This report describes the use of three-dimensional constructive interference in steady state (3D-CISS) and phase-contrast magnetic resonance imaging (PC-MRI) sequences to investigate the etiology of severe hydrocephalus, and the subsequent surgical management and long-term outcome. Case presentation: A 5-month-old male Rhodesian Ridgeback presented with acute, progressive neurological signs culminating in non-ambulatory tetraparesis. Clinical and imaging findings were consistent with non-communicating tetraventricular hydrocephalus with concurrent severe syringomyelia, but conventional MRI failed to identify the cause of cerebrospinal fluid (CSF) flow obstruction. Following failure of medical management, advanced MRI sequences were performed to clarify the underlying etiology and guide surgical planning. These included 3D-CISS for high-resolution anatomical assessment and PC-MRI for dynamic evaluation of CSF flow. The findings demonstrated patent intraventricular CSF flow and no evidence of arachnoid septations within the fourth ventricle, thereby excluding a fourth ventricle arachnoid diverticulum. Instead, the imaging findings supported a presumptive diagnosis of hydrocephalus secondary to lateral aperture occlusion. A ventriculoperitoneal (VP) shunt was placed, resulting in substantial clinical improvement, although mild residual cerebellar deficits persisted. Five months later, the dog experienced acute deterioration. Computed tomography revealed fracture of the distal catheter at the level of its abdominal wall anchoring site, likely due to progressive tension as the dog grew, resulting in the catheter snapping into two segments. Revision surgery restored CSF diversion and led to rapid clinical recovery. The patient remains neurologically stable at 28 months of age, 15 months post-revision. Conclusion: Advanced MRI sequences, particularly 3D-CISS and PC-MRI, were instrumental in supporting the presumptive diagnosis of lateral aperture obstruction as the underlying cause of hydrocephalus and in guiding an individualized, effective surgical strategy. This case highlights the diagnostic and clinical value of advanced MRI techniques in managing complex hydrocephalus.

  PublisherOA PDFDOI

• IUPHAR Article: Psilocybin induces long-lasting effects via 5-HT2A receptors in mouse models of chronic pain

  Pharmacological Research · 2025-03-17 · 9 citations

  articleOpen access

  Chronic pain is a debilitating disease with current treatments lacking efficacy and safety, therefore discovery of new treatments is crucial. Initial studies suggest that psychedelics may be feasible for targeting pain, however clinical and preclinical controlled studies are necessary to further investigate that possibility. In this study we assessed the effects of two classical psychedelics psilocybin and 2,5-Dimethoxy-4-iodoamphetamine (DOI) in two models of chronic pain after systemic administration in male and female mice. Psilocybin and DOI dose-dependently reversed mechanical and cold hypersensitivity in the chemotherapy-induced peripheral neuropathy (CIPN) mouse model with different time-course of action. Similarly, psilocybin and DOI dose-dependently reversed thermal hypersensitivity in the chronic inflammatory mouse model of Complete Freud’s Adjuvant (CFA). The effects of Psilocybin and DOI in both models were mediated by activation of 5-HT 2A receptors (5-HT 2A R). Overall, the present study suggests that classical psychedelics psilocybin and DOI are effective in reducing pain-like behaviors via 5-HT 2A R activation in two mouse models of chronic pain. • Classical psychedelics psilocybin and DOI dose-dependently reversed pain-like behaviors in two chronic pain mouse models. • In contrast to DOI, the effects of psilocybin in the two models of pain lasted for several days. • Both psilocybin and DOI are effective in reducing pain-like behaviors via 5-HT2AR mechanism.

  PublisherDOI

• Clinical Findings and Outcome in 30 Dogs with Presumptive or Confirmed Nerve Sheath Tumors

  Veterinary Sciences · 2024-04-28 · 6 citations

  articleOpen accessSenior authorCorresponding

  Nerve sheath tumors (NSTs) are well-recognized primary nervous system tumors, but there is relatively limited information in dogs including comparison of NSTs in different anatomical locations. This retrospective study describes the clinical features and outcomes in a group of dogs with NSTs affecting the cranial nerves or spinal nerves. Thirty dogs were included, 25 with a presumptive diagnosis and five confirmed by histopathologic analysis. Seven dogs also had cytology of tumor samples, which were supportive of the NST diagnosis in four. Eight dogs had cranial nerve-associated NSTs, with six involving the trigeminal nerve. Twenty-two dogs had spinal nerve-associated NSTs including 13 invading the spinal canal and nine peripheral to the spinal canal, with the majority affecting nerves or nerve roots of the brachial plexus. The prognosis was poor, with dogs being euthanized eventually because of disease progression. Among dogs alive 1 week after diagnosis, the median survival time was 4 months but ranged from 2 weeks to >2 years. While there was a broad overlap between NST locations, survival was generally longer for dogs without spinal canal or intracranial involvement. The results expand available information on NSTs in dogs but should be interpreted with caution given the small number of dogs with a definitive diagnosis. Further investigation is warranted to determine how tumor location, invasiveness, and treatments pursued impact outcome.

  PublisherOA PDFDOI

• Outcome in paraplegic dogs with or without pain perception due to thoracolumbar fibrocartilaginous embolic myelopathy or acute non-compressive nucleus pulposus extrusion

  Frontiers in Veterinary Science · 2024-05-09 · 6 citations

  articleOpen accessCorresponding

  Background: Fibrocartilaginous embolic myelopathy (FCEM) and acute non-compressive nucleus pulposus extrusion (ANNPE) are common causes of acute spinal cord injury in dogs. Outcome among paraplegic deep pain positive (DPP) and deep pain negative (DPN) dogs with either condition and factors influencing recovery have not been clearly established. Methods: Dogs with thoracolumbar FCEM or ANNPE resulting in paraplegia presenting to university hospitals between 2012 and 2022 were retrospectively included. Diagnosis of FCEM or ANNPE was based on clinical and magnetic resonance imaging findings. Outcome was defined as successful (recovery of independent ambulation) or unsuccessful (non-ambulatory ≥3 months following diagnosis or at the time of death/euthanasia). Logistic regression analysis was performed to investigate associations between clinical or imaging variables and outcome. Results: Thirty-one dogs were included. In total, 14 dogs were initially paraplegic DPP (8 FCEM, 6 ANNPE) and 17 dogs were paraplegic DPN (11 FCEM, 6 ANNPE). Outcome was available for 26 dogs (14 DPP, 12 DPN) with a median follow-up time of 182 days (range 0-2,311) including 2 dogs euthanized at the time of diagnosis; 1 of 12 DPN dogs (8.3%) regained independent ambulation, whereas 9 of 14 DPP dogs (64.3%) regained independent ambulation. DPN dogs had a significantly higher risk of not regaining independent ambulation compared with DPP dogs (OR: 47.40, 95% CI: 2.09-1073.99). No other variables were associated with outcome. Conclusion: While recovery of ambulation was possible, these results confirm that the absence of pain perception is a useful negative prognostic indicator in dogs with severe thoracolumbar FCEM or ANNPE.

  PublisherOA PDFDOI

• Quantification of metallic artifact on CT associated with titanium pedicle screws

  Frontiers in Veterinary Science · 2024-07-31 · 1 citations

  articleOpen access1st authorCorresponding

  Background In dogs undergoing vertebral column stabilization, post-operative computed tomography (CT) evaluates implant placement. The impact on the interpretation of metallic artifact associated with titanium implants in dogs remains to be established. Our objective was to quantify metallic artifact on CT associated with titanium pedicle screws. Methods The study design included an in vitro model and a retrospective review of 11 dogs with vertebral column stabilization. Twenty four titanium pedicle screws (6 each: 2.0 mm, 2.7 mm, 3.5 mm, and 4.5 mm) were inserted into a 20% ballistic gel, and CT scan of the construct was performed. Three blinded raters used a bone window to measure the maximum width (effective size) of each screw, one rater measured effective size using an ultrawide window and 45 titanium pedicle screws (3×2.0 mm, 5×2.7 mm, 30×3.5 mm, and 7×4.5 mm) in 11 clinical cases. Effective size measurements were compared to actual screw sizes. Results The effective size was 26.9–43.8%, 9.2–18.5%, and 21.1–30.5% larger than the actual size for the in vitro system (bone window), in vitro system (ultrawide window), and clinical cases, respectively. The mean gross difference for the in vitro measurements varied by implant size ( p < 0.001) and was positively correlated with implant size ( r = 0.846), but the mean percentage difference was negatively correlated with implant size ( p < 0.001). Overestimation was larger for the in vitro model bone window compared to the ultrawide window ( p < 0.001) and clinical cases ( p = 0.001). Conclusion Metallic artifact associated with titanium pedicle screws on CT resulted in an overestimation of screw size. This information might aid in the interpretation of implant placement on post-operative imaging.

  PublisherOA PDFDOI

• Survival in dogs with meningoencephalomyelitis of unknown etiology with and without lesions detected by magnetic resonance imaging

  Journal of Veterinary Internal Medicine · 2024-05-28 · 8 citations

  articleOpen access

  BACKGROUND: The prognosis of individual dogs with meningoencephalomyelitis of unknown etiology (MUE) remains difficult to predict. MUE cases with no lesions detected by magnetic resonance imaging (MRI) occur, but it is unknown whether this finding is associated with prognosis. HYPOTHESIS: MUE cases without detectable lesions on MRI have a better outcome than cases with detectable lesions. ANIMALS: Study included 73 client-owned dogs with MUE presenting to Purdue University Veterinary Hospital from 2010 to 2020. METHODS: Retrospective study. Dogs with a clinical diagnosis of MUE were identified by medical record search. MRI reports were reviewed for presence or absence of lesions consistent with MUE. Clinical findings at presentation, treatment, disease-specific survival, and outcomes including rates of remission and relapse were compared between cases with normal MRI or abnormal MRI. RESULTS: Overall, 54 dogs (74%) were classified as abnormal MRI, and 19 dogs (26%) were classified as normal MRI cases. Death caused by MUE occurred in 1/19 (5%) normal MRI dogs and 18/54 (33%) abnormal MRI dogs (P = .016). Median survival was >107 months in both groups, but survival was significantly longer in the normal MRI group (P = .019). On multivariate analysis, abnormal MRI was significantly related to death (hazard ratio, 7.71; 95% confidence interval 1.03-58.00, P = .0470), whereas significant relationships with death were not identified for either the use of secondary immunosuppressive medications or cerebrospinal fluid nucleated cell count. CONCLUSIONS: MUE dogs with no detectable lesions on MRI have reduced disease-related death compared with dogs with abnormal MRI. The presence or absence of MRI lesions in MUE dogs is prognostically relevant.

  PublisherOA PDFDOI

• Electrodiagnostic testing in dogs with disorders of the spinal cord or cauda equina

  The Veterinary Journal · 2024-02-13 · 1 citations

  articleOpen access1st authorCorresponding

  Electrodiagnostic (EDX) testing is uncommonly utilized in dogs other than for investigation of disorders of the neuromuscular system. In dogs with diseases affecting the spinal cord or cauda equina, EDX testing can provide functional data complementary to imaging information that together can guide therapeutic and management approaches. Additionally, in some clinical scenarios, EDX testing prior to advanced imaging is integral to identifying if there is spinal cord or cauda equina involvement and can aid in determining the appropriate diagnostic path. This review will outline EDX testing methods that have been reported in dogs relating to the diagnosis, monitoring or prognosis of various conditions affecting the spinal cord and cauda equina. The various tests will be briefly outlined regarding how they are performed and what information is provided. The main focus will be on clinical applications including highlighting situations where EDX testing is useful for differentiating between neurologic and non-neurologic presentations. Additional ways these EDX techniques could be incorporated in the management of diseases of the spinal cord and cauda equina in dogs will be presented.

  PublisherDOI

• Use of levetiracetam for the successful treatment of suspected myoclonic seizures: five dogs (2016‐2022)

  Journal of Small Animal Practice · 2024-04-02 · 4 citations

  articleOpen access

  OBJECTIVES: Myoclonic seizures are considered a type of generalised seizure characterised by brief, jerking movements of the body. The aim of this study is to describe cases of suspected canine myoclonic seizure of idiopathic aetiology and to discuss the successful use of the anticonvulsant levetiracetam as treatment in each of these cases. MATERIALS AND METHODS: Dogs with epileptic myoclonus suspected to be idiopathic in aetiology were considered for inclusion. Medical records were reviewed for physical and neurologic examination findings, clinicopathologic results, and diagnostic imaging results. All included dogs were treated with levetiracetam, and their response was reported. RESULTS: Five dogs were included, all of which had suspected myoclonic seizures either observed in-person or on video recording by a board-certified veterinary neurologist. The duration of myoclonic seizures preceding treatment ranged from one day to one year. One dog also experienced a generalised tonic-clonic seizure. All dogs were treated with levetiracetam. Two dogs experienced long-term myoclonic seizure freedom (duration seizure-free of at least 1 year), and two dogs experienced marked decreased myoclonic seizure frequency. One dog experienced immediate abatement of myoclonic seizures, although levetiracetam was only utilised for 1 month following onset of myoclonic seizures in this patient. CLINICAL SIGNIFICANCE: Myoclonic seizures can be idiopathic in aetiology. Levetiracetam can be used effectively to rapidly stop myoclonic seizures and to decrease the frequency of myoclonic seizures.

  PublisherOA PDFDOI

• Pharmacology of Classical Psychedelic in Mouse Models of Chronic Pain

  Journal of Pain · 2024-04-01 · 2 citations

  articleOpen access
  PublisherOA PDFDOI

Frequent coauthors

• Natasha J. Olby

  North Central State College

  12 shared

• Stephanie A. Thomovsky

  Purdue University West Lafayette

  11 shared

• Peter J. Early

  North Carolina State University

  6 shared

• Jessica Bowditch

  5 shared

• Charles H. Vite

  University of Pennsylvania

  5 shared

• Mallory Lind

  Purdue University West Lafayette

  4 shared

• D. Colette Williams

  University of California, Davis

  4 shared

• George E. Moore

  Purdue University West Lafayette

  4 shared

Labs

• Neurotrauma and Spinal Cord Injury Research LabPI

Education

• Ph.D., Veterinary Science

  North Carolina State University

  2008

• M.S., Veterinary Science

  North Carolina State University

  2003

• B.S., Animal Science

  North Carolina State University

  2001