Transcriptome analysis of ciliary-dependent MCH signaling in differentiating 3T3-L1 pre-adipocytes.

An understanding of adipocyte responsiveness to G-protein-coupled receptor-(GPCR) derived signals must take into consideration the role of membrane microenvironments; that individual sub-populations of proteins may vary significantly across different regions of the cell, and that cell differentiation alters those microenvironments. 3T3-L1 pre-adipocytes undergo a dramatic phenotypic transformation during differentiation into adipocytes, requiring the development of a transient primary cilium. We demonstrate that melanin-concentrating hormone (MCH) receptor 1, a GPCR that stimulates appetite, translocates to the transient primary cilium during early 3T3-L1 cell adipogenesis. Furthermore, we used RNA-Seq to investigate whether MCH signaling is influenced by its receptor localization and whether MCH can influence the transcriptome of early adipocyte development. We found that MCH signaling is sensitive to receptor localization to cilia, and this alters the adipogenic transcriptional program. Also, novel MCH signaling pathways in 3T3-L1 cells are identified, including those for circadian rhythm, the inflammatory response, and ciliary biogenesis. The presence of active MCH-signaling pathways in pre-adipocytes and the discovery that these pathways intersect with the early adipogenic program, among other newly-identified signaling pathways, suggests that the use of MCH receptor 1 antagonists for clinical interventions may have unintended consequences on adipose tissue development.

Short-term efficacy of epidural pain management in dogs undergoing cystoscopy.

BACKGROUND: The effects of epidural anesthesia in dogs undergoing cystoscopy are unknown. OBJECTIVE: To investigate the effect of epidural analgesia on postcystoscopy pain in dogs. ANIMALS: Twenty-six dogs undergoing routine cystoscopy for lower urinary tract disease. METHODS: Prospective, randomized, blinded observational study. Dogs were assigned either to a treatment group that received epidural anesthesia (preservative free morphine sulfate, 0.09 mg/kg; 1% ropivacaine, 0.2 mg/kg; total volume delivered, 1 mL/4.5 kg of body weight to a maximum of 10 mL; n = 9) or to a nonepidural control group (n = 13). Vital signs were monitored for 24 hours, and sedation and pain scores, behavioral assessments, and presence or absence of complications was evaluated for 5 days postprocedure. RESULTS: All dogs tolerated the epidural without complications. Four dogs were removed from the study because of status unblinding, lack of patient cooperation, or incomplete follow-up. No significant differences were noted in postprocedural pain scores in dogs that received epidural analgesia. Significant differences in postprocedural pain scores were noted in the nonepidural control group. No significant differences were noted in vital signs, behavioral assessments, or the proportion of dogs with a 50% increase in pain scores between the epidural and nonepidural groups. CONCLUSIONS AND CLINICAL IMPORTANCE: Epidural anesthesia was well-tolerated. Dogs not receiving the epidural had poor postprocedural pain control. A consistent benefit for the epidural vs nonepidural group could not be identified. Additional studies are required to better assess the impact and efficacy of epidural anesthesia for cystoscopic procedures.

Long-term clinical and magnetic resonance imaging follow-up of dogs with osseous-associated cervical spondylomyelopathy.

BACKGROUND: Osseous-associated cervical spondylomyelopathy (OA-CSM) is a complex disorder with limited long-term survival. The longitudinal progression is currently unknown. OBJECTIVE: To describe changes on magnetic resonance imaging (MRI) over a 2-year minimum period. We hypothesized that spinal lesions would progress in the majority of dogs. ANIMALS: Eleven dogs previously diagnosed with OA-CSM were prospectively studied. Nine dogs were treated medically, whereas 2 were treated surgically. METHODS: Clinical and MRI follow-up were performed with a median time between MRI studies of 30 months (range, 24-54). Morphologic assessment evaluated vertebral canal stenosis, spinal cord compression, foraminal stenosis, and articular processes, among other variables. Morphometric assessment included vertebral canal area, spinal cord area, area of the articular processes, and foraminal height. RESULTS: On follow-up MRI, the most affected site at the initial examination in medically treated dogs had progressed in 4 of 9 dogs, improved in 4, and was unchanged in 3. Clinically, all dogs except 2 medically treated dogs were unchanged to improve at follow-up. Initially, 50 of 60 (83.3%) intervertebral spaces had vertebral canal stenosis, whereas in the follow-up MRI 82.3% did. Of the sites with stenosis, 45.7% were unchanged, 18.6% improved, and 38.9% worsened. Morphometry identified significant decreases in vertebral canal and spinal cord areas at C4-C5 through C6-C7, and significant progression of articular process irregularities at C3-C4 and C6-C7. CONCLUSIONS AND CLINICAL IMPORTANCE: This long-term follow-up study of dogs with OA-CSM did not identify clinical or MRI progression of lesions in the majority of dogs.

Progressive Myelomalacia in a Pomeranian Following Spinal Fracture and Surgical Stabilization-A Case Report.

A 4-year-old female spayed Pomeranian presented for being unable to use its pelvic limbs after a fall. The dog was paraplegic with absent pelvic limb nociception and a Schiff-Sherrington posture. Radiographs and Computed tomography showed a T11-T12 luxation. Spinal stabilization was performed for pain control. Twenty-four hours following surgery the patient lost pelvic limb reflexes. Twelve hours later she lost cutaneous trunci and forelimb proprioception and had increased respiratory effort. A diagnosis of progressive myelomalacia was made and the patient was euthanized. Most cases of progressive myelomalacia in dogs are due to intervertebral disc herniation. To the authors' knowledge, myelomalacia secondary to spinal fracture has not been reported.

Mechanical quantitative sensory testing in cavalier King Charles spaniels with and without syringomyelia.

BACKGROUND: Syringomyelia (SM) is a debilitating condition in the cavalier King Charles spaniel (CKCS) that results in neuropathic pain and diminished quality of life. Von Frey aesthesiometry (VFA) is a method of mechanical quantitative sensory testing that provides an objective sensory threshold (ST) value and can be used to quantify neuropathic pain (NP) and monitor response to therapy. The utility of VFA has been previously established in client-owned dogs with acute spinal cord injury but the technique has not been evaluated in dogs with SM. The goal of this study was to evaluate ST, as determined by VFA, in dogs with and without SM, to assess the utility of VFA in quantifying NP in SM-affected dogs. We hypothesized the SM-affected CKCS would have lower ST values, consistent with hyperesthesia, when compared to control CKCS. Additionally, we hypothesized that ST values in SM-affected dogs would be inversely correlated with syrinx size on MRI and with owner-derived clinical sign scores. RESULTS: ST values for the thoracic and pelvic limbs differed significantly between the SM-affected and control CKCS (p = 0.027; p = 0.0396 respectively). Median ST value (range) for the thoracic limbs was 184.1 g (120.9-552) for control dogs, and 139.9 g (52.6-250.9) for SM-affected dogs. The median ST value (range) for the pelvic limbs was 164.9 g (100.8-260.3) in control dogs and 129.8 g (57.95-168.4) in SM-affected dogs. The ST values in SM-affected dogs did not correlate with syrinx height on MRI (r = 0.314; p = 0.137). Owner-reported clinical sign scores showed an inverse correlation with pelvic limb ST values, where dogs with lower ST values (hyperesthesia) were reported by their owners to display more frequent and severe clinical signs (r = - 0.657; p = 0.022). CONCLUSION: ST values were lower in SM-affected CKCS compared to control dogs, suggesting the presence of neuropathic pain. Dogs with lower ST pelvic limb values were perceived by their owners to have more severe clinical signs classically associated with SM. Our results suggest that VFA might offer quantitative assessment of neuropathic pain in SM-affected dogs and could be useful for monitoring response to therapy in future clinical studies.

Distemper Encephalomyelitis Presenting with Lower Motor Neuron Signs in a Young Dog.

A 4 mo old spayed female mixed-breed dog was presented for focal lower motor neuron signs of the right forelimb and marked hyperesthesia on axillary palpation. Her signs progressed rapidly over the following days to diffuse lower motor neuron signs in all limbs and a seizure. MRI demonstrated a focal, slightly right-sided, 2.5 cm region of noncontrast-enhancing T2 hyperintensity and T1 isointensity at C4-C5 spinal cord segments. Imaging of the brain was unremarkable. The dog was euthanized as a result of poor prognosis. Polymerase chain reaction on cerebrospinal fluid and immunohistochemistry of brain tissue were both positive for canine distemper virus. This report documents an atypical presentation of canine distemper encephalomyelitis causing lower motor neuron signs and hyperesthesia.

Urological Sequelae to Acute Spinal Cord Injury in Pet Dogs: A Natural Disease Model of Neuropathic Bladder Dysfunction.

The authors review urologic dysfunction, including urine retention, incontinence, and recurrent and resistant urinary tract infection, in dogs as a sequela to acute spinal cord injury. Urologic sequelae to acute spinal cord injury (SCI) pose significant complications in human and canine patients impacting quality of life and long-term cost of treatment. Dogs with intervertebral disc extrusion may serve as a natural disease model of acute SCI for investigating translational interventions, both prophylactic and therapeutic, for urologic dysfunction in human SCI patients.

Hemorrhagic Myelomalacia in a Bichon Frise Following Lumbar Spinal Tap-A Case Report.

A 10-year-old spayed female Bichon Frise presented to the neurology service for back pain and pelvic limb weakness for approximately 2 months duration. Neurologic examination revealed T3-L3 and L4-S3 myelopathies with multifocal spinal pain. Magnetic resonance imaging of the vertebral column revealed multiple mild disc protrusions but no obvious cause for the neurologic deficits. Attempts to collect cerebrospinal fluid from the lumbar spine and cerebellomedullary cistern were unsuccessful. Following anesthesia, the dog was noted to be paraplegic with flaccid pelvic limb muscle tone and absent nociception. Repeat magnetic resonance imaging the following day revealed suspect hemorrhage ventral to the spinal cord cranial to the site of the lumbar spinal tap. Exploratory hemilaminectomy revealed purplish discoloration of the dura. Durotomy was performed and severe myelomalacia of the spinal cord was noted. To the author's knowledge, this is the first reported case of myelomalacia suspected secondary to lumbar spinal tap in a dog.

Clinical features and short-term outcome of presumptive intracranial complications associated with otitis media/interna: a multi-center retrospective study of 19 cats (2009-2017).

OBJECTIVES: The aim of this study was to compile an overview of the clinical features of intracranial complication of otitis media/interna (OMI) in cats managed across five veterinary referral hospitals. Of additional interest were culture results that could inform empirical antibiotic selection, as well as outcome with both medical and surgical management. METHODS: A retrospective medical record review was conducted at five veterinary referral practices to identify cats with a diagnosis of intracranial complication secondary to OMI between 2009 and 2017. Clinical features, diagnostic findings, treatment and outcome were recorded. RESULTS: At total of 19 cats were identified. Sixty-three percent had no previous history of ear infection. Otoscopic examination was normal in 47% of cases. The most common bacterial isolate was Pasteurella multocida, which was identified in 24% of cases. Outcome was successful for 83% of cats managed with ventral bulla osteotomy (VBO) and in 66% of cats managed without surgical intervention. CONCLUSIONS AND RELEVANCE: Clinical suspicion of intracranial complications of OMI should remain high in cats with central vestibular disease even if otoscopic examination is normal. Antibiotic selection should be based on a culture and sensitivity; however, initial antibiotic therapy should include broad-spectrum coverage with special consideration for P multocida. Cats with intracranial complications of OMI can have a good outcome with either surgical or medical management and prospective studies are needed to assess the role of VBO in enhancing recovery.

Characterization of mule deerpox virus in Florida white-tailed deer fawns expands the known host and geographic range of this emerging pathogen.

Infections caused by mule deerpox virus (MDPV) have been sporadically reported in North American cervids. White-tailed deer (Odocoileus virginianus) fawns from a farm located in South Central Florida presented with ulcerative and crusting lesions on the coronary band as well as the mucocutaneous tissues of the head. Evaluation of the crusted skin lesions was undertaken using microscopic pathology and molecular techniques. A crusted skin sample was processed for virus isolation in four mammalian cell lines. The resulting isolate was characterized by negative staining electron microscopy and deep sequencing. Histopathologic evaluation of the skin lesions from the fawns revealed a hyperplastic and proliferative epidermis with ballooning degeneration of epidermal and follicular keratinocytes with intracytoplasmic eosinophilic inclusions. Electron microscopy of cell culture supernatant demonstrated numerous large brick-shaped particles typical of most poxviruses. Polymerase chain reaction assays followed by Sanger sequencing revealed a poxvirus gene sequence nearly identical to that of previous strains of MDPV. The full genome was recovered by deep sequencing and genetic analyses supported the Florida white-tailed deer isolate (MDPV-F) as a strain of MDPV. Herein, we report the first genome sequence of MDPV from a farmed white-tailed deer fawn in the South Central Florida, expanding the number of locations and geographic range in which MDPV has been identified.

MRI Findings of Suprasellar Germ Cell Tumors in Two Dogs.

A 4 yr old border collie presenting for mydriasis and decreased mentation and a 7 yr old Boston terrier presenting for obtundation, head tilt, and paraparesis were both evaluated using MRI. Findings in both included mass lesions of the thalamus and brainstem that were hypo- to isointense on T1-weighted images and hyperintense on T2-weighted images with regions of hypointensity, and robust contrast enhancement and displacement of adjacent structures. Postmortem histopathology findings, tumor location, and a mixed pattern of epithelial cell differentiation were consistent with germ cell tumor in both cases. Germ cell tumor of the suprasellar region is an infrequently reported neoplasm of dogs and imaging findings in this species have not been well described in the prior literature.

Evaluation of osseous-associated cervical spondylomyelopathy in dogs using kinematic magnetic resonance imaging.

Osseous-associated cervical spondylomyelopathy in dogs is characterized by both static and dynamic spinal cord compression; however, standard MRI methods only assess static compression. In humans with cervical spondylotic myelopathy, kinematic MRI is commonly used to diagnose dynamic spinal cord compressions. The purpose of this prospective, analytical study was to evaluate kinematic MRI as a method for characterizing the dynamic component of osseous-associated cervical spondylomyelopathy in dogs. We hypothesized that kinematic MRI would allow visualization of spinal cord compressions that were not identified with standard imaging. Twelve client-owned dogs with osseous-associated cervical spondylomyelopathy were enrolled. After standard MRI confirmed a diagnosis of osseous-associated cervical spondylomyelopathy, a positioning device was used to perform additional MRI sequences with the cervical vertebral column flexed and extended. Morphologic and morphometric (spinal cord height, intervertebral disc width, spinal cord width, vertebral canal height, and spinal cord area) assessments were recorded for images acquired with neutral, flexion, and extension imaging. A total of 25 compressions were seen with neutral positioning, while extension identified 32 compressions. There was a significant association between extension positioning and presence of a compressive lesion at C4-C5 (p = 0.02). Extension was also associated with a change in the most severe site of compression in four out of 12 (33%) dogs. None of the patients deteriorated neurologically after kinematic imaging. We concluded that kinematic MRI is a feasible method for evaluating dogs with osseous-associated cervical spondylomyelopathy, and can reveal new compressions not seen with neutral positioning.

Comparison of harmonic blade versus traditional approach in canine patients undergoing spinal decompressive surgery for naturally occurring thoracolumbar disk extrusion.

OBJECTIVES: To assess feasibility of the harmonic Osteovue blade (HOB) for use in the soft tissue approach for dogs undergoing hemilaminectomy and to compare outcomes between dogs undergoing HOB or traditional approach (TRAD). METHODS: A prospective randomized clinical trial was performed using 20 client-owned dogs with thoracolumbar intervertebral disk extrusion requiring hemilaminectomy. Dogs were randomly assigned to HOB or TRAD. Neurologic function and pain scores were assessed pre-operatively. Intraoperative blood loss and surgical approach time as well as postoperative pain and wound healing scores were recorded. Additionally, neurologic recovery and owner perceived quality of life were recorded at day 10 and 30 postoperative. RESULTS: There was no significant difference in sex distribution, weight, age, preoperative neurological grade and pain score, and perioperative outcome measures between groups. Intraoperative total blood loss was minimal for HOB and TRAD (median: 0 ml (range 0-9) and 2.2 ml (range 0-6.8), respectively; p = 0.165) and approach times were similar (median: 7 min (range 5-12) and 8 min (range 5-13), respectively; p = 0.315). While changes in wound healing scores were similar, changes in postoperative pain scores and neurological function were significantly improved in the HOB compared to the TRAD group. Postoperative complications in the HOB group consisted of automutilation of part of the incision and development of a small soft, non-painful subcutaneous swelling in 1 dog each. CONCLUSIONS: The HOB is a safe and effective tool for the soft tissue approach for routine spinal surgery in dogs and is associated with decreased pain and increased neurological function post-surgery.

Cystic Abnormalities of the Spinal Cord and Vertebral Column.

Cystic lesions of the vertebral column and spinal cord are important differential diagnoses in dogs with signs of spinal cord disease. Synovial cysts are commonly associated with degenerative joint disease and usually affect the cervical and lumbosacral regions. Arachnoid diverticulum (previously known as cyst) is seen in the cervical region of large breed dogs and thoracolumbar region of small breed dogs. This article reviews the causes, diagnosis, and treatment of these and other, less common, cystic lesions.

Inferring landscape-scale land-use impacts on rivers using data from mesocosm experiments and artificial neural networks.

Identifying land-use drivers of changes in river condition is complicated by spatial scale, geomorphological context, land management, and correlations among responding variables such as nutrients and sediments. Furthermore, variations in standard metrics, such as substratum composition, do not necessarily relate causally to ecological impacts. Consequently, the absence of a significant relationship between a hypothesised driver and a dependent variable does not necessarily indicate the absence of a causal relationship. We conducted a gradient survey to identify impacts of catchment-scale grazing by domestic livestock on river macroinvertebrate communities. A standard correlative approach showed that community structure was strongly related to the upstream catchment area under grazing. We then used data from a stream mesocosm experiment that independently quantified the impacts of nutrients and fine sediments on macroinvertebrate communities to train artificial neural networks (ANNs) to assess the relative influence of nutrients and fine sediments on the survey sites from their community composition. The ANNs developed to predict nutrient impacts did not find a relationship between nutrients and catchment area under grazing, suggesting that nutrients were not an important factor mediating grazing impacts on community composition, or that these ANNs had no generality or insufficient power at the landscape-scale. In contrast, ANNs trained to predict the impacts of fine sediments indicated a significant relationship between fine sediments and catchment area under grazing. Macroinvertebrate communities at sites with a high proportion of land under grazing were thus more similar to those resulting from high fine sediments in a mesocosm experiment than to those resulting from high nutrients. Our study confirms that 1) fine sediment is an important mediator of land-use impacts on river macroinvertebrate communities, 2) ANNs can successfully identify subtle effects and separate the effects of correlated variables, and 3) data from small-scale experiments can generate relationships that help explain landscape-scale patterns.

Analyzing the role of receptor internalization in the regulation of melanin-concentrating hormone signaling.

The regulation of appetite is complex, though our understanding of the process is improving. The potential role for the melanin-concentrating hormone (MCH) signaling pathway in the treatment of obesity is being explored by many. It was hypothesized that internalization of MCH receptors would act to potently desensitize cells to MCH. Despite potent desensitization of ERK signaling by MCH in BHK-570 cells, we were unable to observe MCH-mediated internalization of MCH receptor 1 (MCHR1) by fluorescence microscopy. A more quantitative approach using a cell-based ELISA indicated only 15% of receptors internalized, which is much lower than that reported in the literature. When ß-arrestins were overexpressed in our system, removal of receptors from the cell surface was facilitated and signaling to a leptin promoter was diminished, suggesting that internalization of MCHR1 is sensitive to cellular ß-arrestin levels. A dominant-negative GRK construct completely inhibited loss of receptors from the cell surface in response to MCH, suggesting that the internalization observed is phosphorylation-dependent. Since desensitization of MCH-mediated ERK signaling did not correlate with significant loss of MCHR1 from the cell surface, we hypothesize that in this model system regulation of MCH signaling may be the result of segregation of receptors from signaling components at the plasma membrane.

Oral shedding of Bartonella in cats: correlation with bacteremia and seropositivity.

Cats are the main reservoirs of zoonotic Bartonella henselae, B. clarridgeiae and B. koehlerae, transmitted among cats by cat fleas. No study has investigated the presence of Bartonella in the saliva of bacteremic and non-bacteremic cats to correlate it to the level of bacteremia and the presence or absence of oral lesions. Shelter cats from northern California (n=130) and Michigan (n=50) were tested for Bartonella bacteremia by blood culture, presence of Bartonella antibodies and Bartonella DNA in oral swabs. Bacteremia was detected in 45 (25%) cats, mainly from northern California (n=40), which were highly flea infested and were 4 times more likely to be bacteremic than the non-flea-infested cats from Michigan. Overall, 69 (38.3%) cats had Bartonella PCR positive oral swabs. Bacteremic cats were almost 3 times (P=0.003) more likely to have PCR positive oral swabs (59%, 26/44) than non-bacteremic cats (32.5%, 44/135). However, there was no correlation between cats being bacteremic and having oral lesions. Antibody prevalences for B. henselae and B. clarridgeiae were 30% and 42.8%. B. henselae and B. clarridgeiae seropositive cats were almost 4 times (P=0.0001) and 3 times (P=0.003) more likely to have oral lesions than seronegative cats. Despite a higher prevalence (odds ratio=1.73; 95% confidence interval=0.88-3.38) of oral lesions in cats with oral swabs testing PCR positive, no statistical association could be demonstrated in this cat population.

Melanin-concentrating hormone facilitates migration of preadipocytes.

Adipose tissue develops from differentiating preadipocytes that expand and migrate. 3T3-L1 preadipocytes respond to melanin-concentrating hormone (MCH) by increasing leptin production. Here, we investigate whether MCH elicits remodeling of the actin cytoskeleton and whether this translates into altered migratory capacity of these cells. Incubation with MCH resulted in a loss of actin stress fibers accompanied by a change in morphology from a stretched-out fibroblast to a rounded cell. PMC-3881-PI, a MCH receptor 1 antagonist blocked the effect, confirming this receptor is solely responsible for MCH-mediated actin rearrangements. Both a pharmacological activator and inhibitor of phospholipase C were used to demonstrate this molecule's importance to the signaling pathway. Finally, MCH was shown to facilitate preadipocyte migration into a scratch wound, revealing a previously unknown role for MCH in the regulation of cellular migration. We conclude that MCH could influence the expansion of adipose tissue through its ability to enhance preadipocyte migration.

Role of helix 8 of the thyrotropin-releasing hormone receptor in phosphorylation by G protein-coupled receptor kinase.

The thyrotropin-releasing hormone (TRH) receptor undergoes rapid and extensive agonist-dependent phosphorylation attributable to G protein-coupled receptor (GPCR) kinases (GRKs), particularly GRK2. Like many GPCRs, the TRH receptor is predicted to form an amphipathic helix, helix 8, between the NPXXY motif at the cytoplasmic end of the seventh transmembrane domain and palmitoylation sites at Cys335 and Cys337. Mutation of all six lysine and arginine residues between the NPXXY and residue 340 to glutamine (6Q receptor) did not prevent the receptor from stimulating inositol phosphate turnover but almost completely prevented receptor phosphorylation in response to TRH. Phosphorylation at all sites in the cytoplasmic tail was inhibited. The phosphorylation defect was not reversed by long incubation times or high TRH concentrations. As expected for a phosphorylation-defective receptor, the 6Q-TRH receptor did not recruit arrestin, undergo the typical arrestin-dependent increase in agonist affinity, or internalize well. Lys326, directly before phenylalanine in the common GPCR motif NPXXY(X)(5-6)F(R/K), was critical for phosphorylation. The 6Q-TRH receptor was not phosphorylated effectively in cells overexpressing GRK2 or in in vitro kinase assays containing purified GRK2. Phosphorylation of the 6Q receptor was partially restored by coexpression of a receptor with an intact helix 8 but without phosphorylation sites. Phosphorylation was inhibited but not completely prevented by alanine substitution for cysteine palmitoylation sites. Positively charged amino acids in the proximal tail of the beta2-adrenergic receptor were also important for GRK-dependent phosphorylation. The results indicate that positive residues in helix 8 of GPCRs are important for GRK-dependent phosphorylation.

Caveolae as potential mediators of MCH-signaling pathways.

The melanin-concentrating hormone receptor (MCHR) 1 is a G protein-coupled receptor involved in the regulation of appetite and energy expenditure in mammals. Here, we show that MCHR1 partitions to lipid rafts in stably expressing Chinese hamster ovary cells. In addition to co-fractionating with lipid rafts containing caveolin-1 on sucrose gradients, caveolin-1 was present in MCHR1 immunoprecipitates, suggesting that MCHR1 complexes with caveolae. The cholesterol-depleting drug methyl-beta-cyclodextrin impaired MCH-mediated ERK signaling. These data suggest that a functional interaction between MCHR1 and caveolin-1 in lipid rafts exists and provide a basis for further biochemical studies to understand the significance on MCH-mediated signal transduction events.