Medicine and Health Sciences Commons^™

Mechanical Evaluation Of Aluminum Oxide Roughened Screws In Equine Third Metacarpal Bone, Petrisor Baia

LSU Master's Theses

ABSTRACT Objectives – To compare the osseointegration of roughened and electropolished 5.5 mm cortical screws used to secure a 4.5 mm broad dynamic compression plate (DCP) in equine third metacarpal (MC3) bones. Study Design – In vivo study Animals – 5 Adult thoroughbred horses (2-7 years old). Methods – For each horse one MC3 was randomly assigned to secure a 4.5 mm broad DCP with 4aluminum oxide (Al2O3) roughened screws on the dorsal mid diaphysis. Four regular electropolished screws used to secure a similar plate on the contralateral limb served as control. They were removed at 12 weeks and the …

Biomechanical Evaluation Of Medial And Lateral Approaches For Experimentally Created Medial Condylar Fractures Of The Equine Third Metacarpal Bone, Saybl Beauton Sprinkle

LSU Master's Theses

Objective -To compare the compression produced in reduction of experimentally created medial condylar fractures using lag screw fixation with medial vs. lateral approach, and to determine the maximum torque at screw failure. Materials and Methods- Twelve (12) pairs (left and right) 3rd metacarpal bones (MC3) were collected from adult (2-7 years) Thoroughbreds euthanized for reasons unrelated to orthopedic disease. Complete parasagittal medial condylar osteotomies were created at a measurement of 9, 13, and 21 mm axial to the epicondylar fossa on four pairs each of cadaveric MC3 bones resulting in fracture fragments measuring 8, 12, and 20 mm in thickness. …

Mapping And Modeling Of Neglected Tropical Diseases In Brazil And Bolivia, Paula Mischler

LSU Doctoral Dissertations

Accurately defining disease distributions and calculating disease risk is an important step in the control and prevention of diseases. This study used geographical information systems and remote sensing technologies within the MaxEnt ecological niche modeling program to create predictive risk maps for leprosy and Schistosomiasis in Brazil and Chagas disease in both Brazil and Bolivia. New disease cases were compiled for leprosy, Schistosomiasis, and Chagas disease from the Brazilian ministry of Health for 2001 to 2009 and the data was stratified to a 10,000 population for each municipality. Bolivian Chagas prevalence rates were calculated from 2007 to 2009 survey data. …

The Tick Response To Rickettsial Dissemination During Typical And Atypical Rickettsial Infection, Piyanate Sunyakumthorn

LSU Doctoral Dissertations

Ticks are the only disease vectors for spotted fever group (SFG) Rickettsia which are obligate intracellular bacteria belonging to the genus Rickettsia. In nature, ticks maintain the infection of SFG Rickettsia via vertical and horizontal transmission. However, the prevalence of rickettsial transmission is limited to certain species of ticks, and this limitation is known as a specific tick/Rickettsia relationship. Due to the continuous increase of tick-borne rickettsial disease cases in the United States, which contrasts with very low prevalence of Rickettsia in tick vectors, the study of vector competence of tick to Rickettsia is needed in order to understand the …

Arginine Metabolism In The Edwardsiella Ictaluri- Channel Catfish Macrophage Dynamic, Wes Arend Baumgartner

LSU Doctoral Dissertations

Edwardsiella ictaluri encodes a urease operon and an arginine decarboxylase (AdiA) that are required for virulence in head kidney derived macrophages (HKDM). The urease produces ammonia in amounts sufficient to alter environmental pH from acid to neutral. A hypothetical model was proposed, involving arginine metabolism in E. ictaluri infected HKDM, focusing on bacterial urease, AdiA, a second arginine decarboxylase (SpeA), and agmatinase (SpeB). Using fluorescence based ratiometric pH determination of E. ictaluri in live HKDM, it was shown that E. ictaluri modulates HKDM phagosome pH to above six. Urease and AdiA mutants failed to up-regulate vacuole pH, while vacuole pH …

Molecular And Genomic Approaches To Understanding Host-Virus Interactions In Shaping The Outcome Of Equine Arteritis Virus Infection, Yun Young Go

University of Kentucky Doctoral Dissertations

Equine arteritis virus (EAV) is the causal agent of equine viral arteritis, a disease of equids. During natural outbreaks of the disease, EAV can cause abortion in pregnant mares and persistent infection in stallions. Understanding how host cellular proteins interact with viral RNA and viral proteins, as well as their role in viral infection, will enable better characterization of the pathogenesis of EAV and establishment of persistent infection in stallions. Accordingly, we hypothesized that both viral factors and host genetically related factors could influence the outcome of EAV infection in horses. To test this hypothesis, we first combined contemporary molecular …

The Role Of Inflammatory Molecules In Hypertension, Jeffrey Paul Cardinale

LSU Doctoral Dissertations

Hypertension is a serious condition with high morbidity and mortality rates, as well as a major predisposing factor for multiple cardiovascular and renal diseases. Angiotensin II (Ang II) of the renin-angiotensin system (RAS) plays a pivotal role in propagating the hypertensive response. Moreover, hypertension is considered a chronic low-grade inflammatory condition that intimately involves the actions of proinflammatory cytokines (PICs) such as tumor necrosis factor-alpha (TNF). Recent evidence highlights the role that inflammation, specifically TNF, plays in hypertension and in regulating the RAS, but the understanding as to how inflammation is regulated following Ang II or TNF activation, as well …

Arbovirus Phenotype Alters Transmission Potential, Rebecca C. Christofferson

LSU Doctoral Dissertations

Extrinsic and environmental factors are known to affect the transmission of arthropod-borne viruses (arboviruses), including variations in the arthropod vector populations. Differences among these factors have been associated with differential transmission and are sometimes used to control the spread of an arbovirus through a vertebrate population in an effort to prevent or disrupt an outbreak. However, diversity in intrinsic viral populations, such as genetic and phenotypic variability, is not often accounted for when considering alterations in transmission. Presented in this dissertation are four experimental studies that explore the contribution of viral intrinsic factors, especially phenotypic variability, to the transmission potential …

Characterization Of Spiroplasma Mirum And Its Role In Transmissible Spongiform Encephalopathies, Hilari Maree French

LSU Doctoral Dissertations

There are many contradictory reports in the literature involving the culture of Spiroplasma mirum, its resistance to disinfectants and antibiotics, and its potential role in Transmissible Spongiform Encephalopathies (TSEs). These contradictions led to an interest in a possible link between spiroplasma and TSEs and the development of a research plan to elucidate this connection. It was hypothesized that Spiroplasma was associated with a neurodegenerative disease such as TSE. In this work we further characterized S. mirum laboratory strains and continued to evaluate the possible correlations they have with TSE infections and the prion. To optimize recovery of S. mirum from …

Duration Of Immunity Following The Administration Of Oil-Based Avian Influenza H_5n_1 Vaccine In Layers, Maryam Nisar, Anwar-Ul Haq, Asif Rashid, Muhammad Iqbal

Turkish Journal of Veterinary & Animal Sciences

Avian influenza (AI) occurs worldwide and causes tremendous economic losses. The disease is characterised by respiratory signs, depression, and reduced food and water intake. In the present study, an oil-based vaccine created by using Montanide ISA 70 MVG, was prepared and the duration of immunity checked at different time intervals. For this purpose, the cumulative mean titre (CMT) was calculated after employing haemagglutination inhibition test in 50 pullets at day zero before vaccination and then inoculated 0.3 mL of emulsified vaccine subcutaneously in 40 birds while 10 birds were kept non-vaccinated as a control group throughout the experiment. On day …

Aflatoxin M1 Contamination In Cow’S Milk In Kayseri (Central Turkey), Hi̇kmet Mavuş Buldu, A. Nedret Koç, Güven Uraz

Turkish Journal of Veterinary & Animal Sciences

The purpose of this study was to determine the levels of aflatoxin M1 (AFM1) in the milk of cows in the villages of Kayseri province, Turkey. Ninety milk samples were investigated for AFM1 contamination using the enzyme linked immunoassay (ELISA). The mean value of AFM1 levels was 59.9 ng/L, 95% confidence interval was 54.4-65.5 ng/L, and standard deviation was 26.6 ng/L. For 63 samples (70%) the values were significantly above the limit permitted by European Union criteria (EU) and the Turkish Food Codex (TFC) (P < 0.05). However, the differences in AFM1 levels between villages were not significant (P > 0.05). In conclusion, since the level of AFM1 in the milk of cows was higher …

Eosinophils In Lung Tissue In 2 Chilean Criollo Horses With Exacerbated Recurrent Airway Obstructions “Heaves”, Alexander Ortloff, Hugo Folch, Gabriel Moran

Turkish Journal of Veterinary & Animal Sciences

We report on 2 cases of recurrent airway obstruction (RAO) observed in Chilean Criollo horses aged 13 and 15 years. Both animals were classified as having severe RAO. The analysis of the recovered cells of bronchoalveolar lavage fluid (BALF) showed high percentages of eosinophils (82% and 80% in the differential cell counts of the 2 horses) and poor responses to bronchodilator and corticosteroid drugs. The histopathological lung evaluation showed eosinophilic infiltration in the peribronchial tissue, as well as in the lumen of the bronchi and bronchioli. In both horses, immunohistochemistry confirmed high p65 homodimer activity in bronchial cells. This report …

Bilateral Testicular Hypoplasia Among Mature Sahel Bucks In Nigeria, Ikechukwu Igbokwe, Augustine Ikpo, Hafsat Grema, Fakilahyel Mshelbwala, Nanacha Igbokwe

Turkish Journal of Veterinary & Animal Sciences

Among 1608 Sahel goat bucks presented for slaughter at the Maiduguri Metropolitan abattoir in March-April 2007, 65.7% had plain white or black-white coat colour, and 91.2% were aged >1.5-3.0 years with mean body weights of 15.6-25.7 kg. Twenty-two (1.4%) of the mature bucks, aged 1.9 ± 0.3 years and weighing 20.6 ± 3.5 kg, had bilateral small hypoplastic testes that were symmetric, approximately 7 times smaller in weight, with a 2-fold reduction in longitudinal length and mid-circumference than the full-sized normal testes. The epididymes were also reduced in size as the testes. Histologically, the seminiferous tubules and caudal epididymides showed …

Statistical Evaluation Of Some Environmental Factors Affecting The Gross Efficiency Of Crude Protein In High Producing Dairy, Pouya Zamani, Seyed Reza Miraei Ashtiani, Daryoush Alipour, Hasan Aliarabi, Ali Asghar Saki, Ahmad Ahmadi, Khalil Zaboli

Turkish Journal of Veterinary & Animal Sciences

Some environmental factors affecting the gross efficiency of crude protein (GECP) were studied using 2824 records of 501 lactating Holstein cows. The effects of some independent variables on the GECP were tested using a general linear model analysis. The GECP was significantly affected by parity and pregnancy stage and linearly related to dry matter intake, milk yield, milk fat, protein and lactose percentages, protein and lactose yields, dietary levels of net energy for lactation (NEL), crude protein (CP), ruminally undegradable protein (RUP), and ether extract (EE). Quadratic relation to the GECP with dietary levels of NEL, CP, RUP, and EE …

Analysis Of Buffalo Liver Samples For The Presence Of Chlorpyrifos Residues By Using High Performance Liquid Chromatography, Pradeep Kumar, S.P. Singh, K. Shrikant, D. Madhukar

Turkish Journal of Veterinary & Animal Sciences

Food safety is of great importance to all involved in the food chain. The problem of pesticide residues is one of the concerns for the consumers. In the present study, 254 buffalo liver tissue samples were collected from 4 slaughterhouses and analyzed both qualitatively and quantitatively for the presence of chlorpyrifos residues. The samples were processed by extraction with acetonitrile followed by sonication and liquid-liquid partition. The extracts were cleaned up by performing alumina column chromatography. Chlorpyrifos residues in the samples were detected and quantified by employing high performance liquid chromatography. High performance liquid chromatography (HPLC) was performed by using …

Expression And Detection Of The Fmdv Vp1 Transgene And Expressed Structural Protein In Arabidopsis Thaliana, Li Pan, Yongguang Zhang, Yonglu Wang, Jianliang Lv, Peng Zhou, Zhongwang Zhang, Yuzhen Fang, Shoutian Jiang

Turkish Journal of Veterinary & Animal Sciences

To explore the feasibility of developing a new type of plantderived foot-and-mouth disease virus (FMDV) oral vaccine, the plant seed-specific expression vector p7SBin438/VP1 carrying the VP1 gene of the FMDV strain O/China/99 was constructed and transformed into Agrobacterium tumefaciens strain GV3101. This strain was used for transformation of Arabidopsis thaliana via the floral-dip method. The kanamycin-resistant transgenic plants were selected, and the VP1 gene and protein expressions were confirmed by PCR and sandwich-ELISA, respectively. The ELISA positive plants were further confirmed by Western blot assay, and the VP1 gene in the transgenic progeny was confirmed by PCR. The results showed …

Pathological And Immunohistochemical Evaluation Of The Effects Of Interferon Gamma (Ifn-Γ) And Aminoguanidine In Rats Experimentally Infected With Fasciola Hepatica, Enver Beytut, Ati̇la Akça, Hali̇l İbrahi̇m Gökce

Turkish Journal of Veterinary & Animal Sciences

The present study was aimed at pathologically and immunohistochemically evaluating the effects of interferon gamma (IFN-\gamma) and aminoguanidine (AG) in rats experimentally infected with Fasciola hepatica. A total of 44 Wistar rats were divided into 4 groups. With the exception of the controls (fourth group), the remaining rats were infected orally with 25 metacerceria of F. hepatica. The first group was administered 0.2% AG in drinking water daily, in order to block nitric oxide (NO) production. The second group was administered 250 units of IFN-\gamma daily, in order to stimulate NO synthesis. The third group was administered a placebo only. …

Effect Of Dietary Supplementation Of Mannan Oligosaccharides On Hydrogen Ion Concentration Of The Digestive Tract And Microbial Populations Of The Ceca Of Japanese Quail (Coturnix Japonica), Eleftherios Bonos, Efterpi Christaki, Amin Abrahim, Nikolaos Soultos, Panagiota Florou-Paneri

Turkish Journal of Veterinary & Animal Sciences

The effect of the dietary supplementation of mannan oligosaccharides (MOS) on hydrogen ion concentration of the digestive tract and microbial populations of the ceca of the Japanese quail (Coturnix japonica) was investigated in this experimentation. Two hundred twenty-five 1-day old Japanese quail divided into 3 groups, with 3 subgroups each, were fed a basal diet that served as control, or a basal diet containing 1 g MOS/kg or 2 g MOS/kg. On days 21 and 42, hydrogen ion concentrations of the quail crop, proventriculus, gizzard, duodenum, jejunum, ileum, large intestine, and ceca were measured in situ. Furthermore, on the same …

Infectious Pancreatic Necrosis In A Recirculating Rainbow Trout (Oncorhynchus Mykiss) Culture System, Nasrollah Ahmadi, Mostafa Akhlaghi, Ahmad Oryan, Arsalan Hosseini

Turkish Journal of Veterinary & Animal Sciences

During October 2009, a suspected outbreak of infectious pancreatic necrosis, with typical signs and high mortality, was observed in cultured rainbow trout (Oncorhynchus mykiss) fry (mean weight of 9 g) in a recirculating system in Fars Province, Iran. Tissue samples, including pyloric caeca as well as pancreatic tissues, liver, kidney, and spleen, were aseptically collected from 20 affected moribund fish for histopathological and molecular assays. Histopathologically, the exocrine pancreatic acinar cells exhibited the most notable pathology, including focal to extensive degeneration and coagulative necrosis with mononuclear inflammatory infiltrates. To confirm the diagnosis of clinical infectious pancreatic necrosis (IPN), a reverse …

First Report Of Fasciola Hepatica In Equus Caballus Host Species From Tunisia Based On The Ribosomal Internal Transcribed Spacer Regions, Nabil Amor, Sarra Farjallah, Khaled Said, Badreddine Ben Slimane

Turkish Journal of Veterinary & Animal Sciences

Fasciolosis caused by Fasciola spp. (Platyhelminthes: Trematoda: Digenea) is considered the most important helminth infection of ruminants in tropical countries, causing considerable socioeconomic problems. Samples identified morphologically as Fasciola sp. in Equus caballus host species from the city of Tunis (north of Tunisia) were genetically characterized, for the first time, by sequences of the 1st (ITS-1), the 5.8S and 2nd (ITS-2) Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA (rDNA). Comparison of the ITS of the Tunisian samples with sequences of Fasciola spp. from GenBank showed that the specimens examined had sequences identical to those of F. hepatica sequences selected …

Chronic Continuous Perfusion Of The Hibernation Triggering Opioid Dadle Did Not Cause Any Major Physiological Alterations In Rats, İbrahi̇m Akyazi, Ülker Çöteli̇oğlu

Turkish Journal of Veterinary & Animal Sciences

[D-Ala2, D-Leu5] enkephalin (DADLE), a delta opioid receptor agonist, can induce mammalian hibernation and has hibernation-like effects in non-hibernating species. It has also been demonstrated that DADLE has protective efficacy on various tissues such as nervous, cardiac, and hepatic tissues. Despite substantial research conducted in the last decade about the tissue protective efficacy of DADLE, detailed underlying mechanisms have not been fully elucidated. In the present study we investigated in a rat model whether continuous perfusion of DADLE can induce potentially tissue protective alterations in physiological parameters. In the study 48 young male Wistar rats were used. They were divided …

Can The Vascular Endothelial Growth Factor (Vegf) And Total Estradiol 17Β Be Used As A Marker Of Equine Oocyte Maturation?, Mehmet Can Gündüz, Güven Kaşikçi, Özge Yilmaz, Si̇nem Özlem Engi̇nler, Meli̇h Uçmak, Ati̇la Ateş, Feraye Esen Gürsel, Gamze Evkuran, Meri̇h Duygu Töre

Turkish Journal of Veterinary & Animal Sciences

The aim of this study was to quantitate vascular endothelial growth factor (VEGF) and estradiol-17\beta in follicular fluid (FF) and serum and to correlate the levels of these substances with oocyte maturation. Transvaginal ultrasound-guided follicular aspirations were performed with the purpose of oocyte collection when the follicle was >35 mm in diameter. The mares were divided into 2 groups according to age, and the changes in VEGF and estradiol-17\beta in follicular fluid and serum were examined. Levels of estradiol-17\beta in the follicular fluid and serum of young mares (4-10 years old) did not differ from those in old mares (20-24 …

The Effect Of Organic Acid, Zeolite, Or Their Combination On Performance, Some Serum Indices, And Ileum Ph Values In Broilers Fed With Different Phosphorus Levels, İsmai̇l Abaş, Tanay Bi̇lal, Hüseyi̇n Eseceli̇

Turkish Journal of Veterinary & Animal Sciences

The aim of this study was to investigate the effects of the addition of organic acid (OA), zeolite (ZE), or both to broiler diets with microbial phytase containing low and adequate levels of phosphorus (P) on performance, some serum indices, and ileum pH values. For the study, 480 broiler chicks 1-day old were assigned equally to 8 groups, with 6 replicates (10 chicks per replicate) carried out over 42 days. A basal diet containing 600 FTU of phytase enzyme was formulated separately for the starter and grower periods. Experimental groups were divided into 2 main groups: low P [(0.39% P; …

The Laser In Veterinary Medicine, Mihaela Antonina Calin, Toma Coman

Turkish Journal of Veterinary & Animal Sciences

The development of non-invasive, non-toxic, and non-pollutant methods for the treatment of different illnesses represents a constant concern of scientists from the medical field worldwide. In this category fit the methods based on the use of laser systems, which are successfully applied both in human and veterinary medicine due to the special properties of laser radiation: monocromaticity, coherence, intensity, and directionality. The aim of this paper is to present the laser systems used in several domains of veterinary medicine and some experimental results obtained by different authors.

Hyalomma Rufipes (Koch, 1844) Infesting Cattle In The West Aegean Region Of Turkey, Serkan Bakirci, Hakan Sarali̇, Levent Aydin, Abdalla Latif, Hasan Eren, Tüli̇n Karagenç

Turkish Journal of Veterinary & Animal Sciences

A total of 19,679 adult ticks were collected from 443 cattle in 9 villages in the West Aegean region of Turkey over 2 years (June 2006-May 2008). Thirteen out of the 19,679 adult ticks were identified as Hyalomma rufipes (12 adult males and 1 female). The ticks were identified according to their characteristic dark coloured conscutum and scutum along with the presence of small to medium but uniform and numerous punctations. Dimensions (length and width) of male and female H. rufipes ticks were 3075 and 1880 µm and 3213 and 2181 \mum, respectively. The present study not only confirms previous …

Congenital Secundum Atrial Septal Defect And Membranous Ventricular Septal Defect In A Newborn Holstein-Friesian Calf, Ayşe Haligür, Mehmet Haligür, Özlem Özmen

Turkish Journal of Veterinary & Animal Sciences

Congenital secundum atrial septal defect (ASD) and membranous ventricular septal defect (VSD) were diagnosed in a 1-day-old Holstein-Friesian calf necropsied in the Department of Pathology of Mehmet Akif Ersoy University. The secundum atrial septal defect was 32.9 × 23.1 mm in width and was elliptical. The membranous ventricular septal defect was 25.3 × 18.5 mm in width and was round to oval in shape. Both atrial and ventricular septal defects were stained with hematoxylin-eosin and Van Gieson's stain. Histopathological examination showed that the defects mainly consisted of numerous muscle cells and, in some areas, dense fibrous connective tissue.

The Need To Quantify Ecosystem Services Provided By Birds, Daniel G. Wenny, Travis L. Devault, Matthew D. Johnson, Dave Kelly, Cagan H. Sekercioglu, Diana F. Tomback, Christopher J. Whelan

United States Department of Agriculture Wildlife Services: Staff Publications

What are the birds worth--what is their actual dollar value to human society? To most of us in the ornithological community, birds are invaluable. But in these times we need more specific rationales to convince policy makers and business leaders to include bird conservation in land-use and development decisions. Over the past two decades, awareness of our dependence on a variety of ecosystem services (natural ecological processes that benefit human society) and of their importance and prevalence has progressed toward the goal of making conservation a mainstream value. Building strategies for the protection of ecosystem services into conservation and land-use …

Development, Optimization, And Validation Of A Classical Swine Fever Virus Real-Time Reverse Transcription Polymerase Chain Reaction Assay, August J. Eberling, Jill Bieker-Stefanelli, Monica M. Reising, David Siev, Barbara M. Martin, Michael T. Mcintosh, Tammy R. Beckham

Zoonotics and Wildlife Disease: Publications

Classical swine fever (CSF) is an economically devastating disease of pigs. Instrumental to the control of CSF is a well-characterized assay that can deliver a rapid, accurate diagnosis prior to the onset of clinical signs. A real-time fluorogenicprobe hydrolysis (TaqMan) reverse transcription polymerase chain reaction (RT-PCR) for CSF was developed by the United States Department of Agriculture (USDA) at the Plum Island Animal Disease Center (CSF PIADC assay) and evaluated for analytical and diagnostic sensitivity and specificity. A well-characterized panel including Classical swine fever virus (CSFV), Bovine viral diarrhea virus (BVDV), and Border disease virus (BDV) isolates was utilized in …

Rodents And Other Vertebrate Invaders In The United States, Michael W. Fall, Michael L. Avery, Tyler A. Campbell, Peter J. Egan, Richard M. Engeman, David Pimentel, William C. Pitt, Stephanie A. Shwiff, Gary W. Witmer

United States Department of Agriculture Wildlife Services: Staff Publications

Contents

Introduction

Assessing impacts of rodents and other vertebrate invaders

Accounts of some important vertebrate invaders
Norway rat (Rattus norvegicus)
Roof rat (Rattus rattus)
Polynesian rat (Rattus exulans)
House mouse (Mus Musculus)
Nutria (Myocastor coypus)
Gambian giant pouched rat (Cricetomys gambianus)
Feral swine (Sus scofa)
Small Indian Mongoose (Herpestes javanicus)
Rock pigeon (Columba livia)
House sparrow (Passer domesticus)
European starling (Sturnus vulgaris)
Monk parakeet (Myiopsitta monachus)
Brown tree snake (Boiga irregularis)
Burmese python (Python …

Carbenoxolone Blocks The Light-Evoked Rise In Intracellular Calcium In Isolated Melanopsin Ganglion Cell Photoreceptors, Jayne R. Bramley, Erin M. Wiles, Patricia J. Sollars, Gary E. Pickard

School of Veterinary and Biomedical Sciences: Faculty Publications

Background: Retinal ganglion cells expressing the photopigment melanopsin are intrinsically photosensitive (ipRGCs). These ganglion cell photoreceptors send axons to several central targets involved in a variety of functions. Within the retina ipRGCs provide excitatory drive to dopaminergic amacrine cells via glutamatergic signals and ipRGCs are coupled to widefield GABAergic amacrine cells via gap junctions. However, the extent to which ipRGCs are coupled to other retinal neurons in the ganglion cell layer via gap junctions is unclear. Carbenoxolone, a widely employed gap junction inhibitor, greatly reduces the number of retinal neurons exhibiting non-rod, non-cone mediated light-evoked Ca²⁺ signals suggesting extensive …