Digital Commons Network^™

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 …

Haematology Of Downer Dairy Cows With Fatty Liver, Emmanouil Kalaitzakis, Nikolaos Panousis, Nikolaos Roubies, Eleni Kaldrymidoy, Harilaos Karatzias

Turkish Journal of Veterinary & Animal Sciences

This study examined downer dairy cows with concurrent fatty liver of different degrees and evaluated the haematological values, the relationship and joint occurrence of fatty liver severity and haematology and compared the haematological values in the downer animals that finally died or cured. Blood and liver biopsy samples were obtained from 36 Holstein downer cows shortly after they became recumbent and before they were treated. Blood analysis included determination of haematocrit, haemoglobin, white blood, granular cell and lymphocytes count, and platelet number. Liver tissue was examined histologically and was classified according to severity of fatty liver. The majority of downer …

A Comparison Of Different Kinds Of Malassezia Species In Healthy Dogs And Dogs With Otitis Externa And Skin Lesions, Samaneh Eidi, Ali Reza Khosravi, Shahram Jamshidi

Turkish Journal of Veterinary & Animal Sciences

Malassezia yeasts are commensal organisms on the skin of warm-blooded vertebrates. The lipid-dependent Malassezia species have recently been cultured from veterinary specimens. The present study investigated and compared different Malassezia species in the skin and external ear canal of healthy and diseased dogs. The sampling in the study was carried out on 152 animals, comprising 90 samples from the diseased group and 62 samples from the healthy group. All of the samples were determined by cytological examination and fungal culture. The isolated yeasts were identified by their morphological features as well as their physiological characteristics. The culture results were positive …

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 …

Y-Like Retinal Ganglion Cells Innervate The Dorsal Raphe Nucleus In The Mongolian Gerbil (Meriones Unguiculatus), Liju Luan, Chaoran Ren, Benson Wui-Man Lau, Jian Yang, Gary E. Pickard, Kwok-Fai So, Mingliang Pu

School of Veterinary and Biomedical Sciences: Faculty Publications

Background: The dorsal raphe nucleus (DRN) of the mesencephalon is a complex multi-functional and multi-transmitter nucleus involved in a wide range of behavioral and physiological processes. The DRN receives a direct input from the retina. However little is known regarding the type of retinal ganglion cell (RGC) that innervates the DRN. We examined morphological characteristics and physiological properties of these DRN projecting ganglion cells.

Methodology/Principal Findings: The Mongolian gerbils are highly visual rodents with a diurnal/crepuscular activity rhythm. It has been widely used as experimental animals of various studies including seasonal affective disorders and depression. Young adult gerbils were used …

Regulation Of The Latency–Reactivation Cycle By Products Encoded By The Bovine Herpesvirus 1 (Bhv-1) Latency-Related Gene, Clinton Jones, Leticia Frizzo Da Silva, Devis Sinani

School of Veterinary and Biomedical Sciences: Faculty Publications

Like other α-herpesvirinae subfamily members, the primary site for bovine herpesvirus 1 (BHV-1) latency is ganglionic sensory neurons. Periodically BHV-1 reactivates from latency, virus is shed, and consequently virus transmission occurs. Transcription from the latency-related (LR) gene is readily detected in neurons of trigeminal ganglia (TG) of calves or rabbits latently infected with BHV-1. Two micro-RNAs and a transcript encompassing a small open reading frame (ORF-E) located within the LR promoter can also be detected in TG of latently infected calves. A BHV-1 mutant that contains stop codons near the beginning of the first open reading frame (ORF2) within the …

Challenges And Opportunities For Toxicology In Mexico, Rodrigo Franco, Balam Muñoz

School of Veterinary and Biomedical Sciences: Faculty Publications

We have developed this Special Issue titled “Challenges and Opportunities for Toxicology in Mexico” with the aim to highlight not only the challenges toxicology research faces in Mexico, but also the efforts and drive towards cutting edge research to address them. Altogether, this special issue should be a valuable source of information for all readers with an interest in toxicology and human health.

Mexico is an important economy worldwide and is a major exporter of several supplies and commodities. Because of this, its industry is a source of occupational exposure to several chemical derivatives (Nieusma 2011). The situation of occupational …

Intrinsically Photosensitive Retinal Ganglion Cells, Gary E. Pickard, Patricia J. Sollars

School of Veterinary and Biomedical Sciences: Faculty Publications

Intrinsically photosensitive retinal ganglion cells (ipRGCs) respond to light in the absence of all rod and cone photoreceptor input. The existence of these ganglion cell photoreceptors, although predicted from observations scattered over many decades, was not established until it was shown that a novel photopigment, melanopsin, was expressed in retinal ganglion cells of rodents and primates. Phototransduction in mammalian ipRGCs more closely resembles that of invertebrate than vertebrate photoreceptors and appears to be mediated by transient receptor potential channels. In the retina, ipRGCs provide excitatory drive to dopaminergic amacrine cells and ipRGCs are coupled to GABAergic amacrine cells via gap …

Long-Term Clinicopathological Characteristics Of Alpacas Naturally Infected With Bovine Viral Diarrhea Virus Type Ib, D. Bedenice, Edward J. Dubovi, Clayton Kelling, Jamie N Henningson, Christina L. Topliff, N. Parry

School of Veterinary and Biomedical Sciences: Faculty Publications

Background: Substantial bovine viral diarrhea virus (BVDV)-related production losses in North American alpaca herds have been associated with BVDV type Ib infection.

Objectives: To classify and differentiate the long-term clinicopathological characteristics of BVDV type Ib infection of al- paca crias, after natural virus exposure. We hypothesized that persistently infected (PI) alpacas specifically demonstrate growth retardation, clinicopathological evidence of opportunistic infections, and early mortality.

Animals: Thirty-five crias naturally exposed to BVDV (18 acute, 3 chronic, 14 PIs), and 19 healthy cohort controls of 5 northeastern alpaca farms were prospectively evaluated over 2 years (September 2005–September 2008).

Methods: Observational cohort-control study.

Results: …

Gender Differences In Cns Autoimmunity Induced By Mimicry Epitope For Plp 139–151 In Sjl Mice, Chandirasegara Massilamany, Sivasubramani Thulasingam, David Steffen, Jay Reddy

Jay Reddy Publications

Development of multiple sclerosis (MS) is more prevalent in females than in males, but the underlying mechanisms are not clear. Microbial infections have been suspected as triggers of MS and it is not known whether gender differences in reactivity to environmental antigens contribute to the disease pathogenesis. We demonstrated that ACA 83–95, a mimicry epitope from Acanthamoeba castellanii for proteolipid protein (PLP) 139–151, induces clinical signs of encephalomyelitis in both male and female SJL mice. Conversely ACA 83–95-induced effector cells from males fail to induce disease in female mice. Although we found no gender differences in the frequencies of antigen-specific …

Rnai Screening Reveals Requirement For Host Cell Secretory Pathway In Infection By Diverse Families Of Negative-Strand Rna Viruses, Debasis Panda, Anshuman Das, Phat X. Dinh, Sakthivel Subramaniam, Debasis Nayak, Nicholas J. Barrows, James L. Pearson, Jesse Thompson, David L. Kelly, Istvan Ladunga, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

Negative-strand (NS) RNA viruses comprise many pathogens that cause serious diseases in humans and animals. Despite their clinical importance, little is known about the host factors required for their infection. Using vesicular stomatitis virus (VSV), a prototypic NS RNA virus in the family Rhabdoviridae, we conducted a human genomewide siRNA screen and identified 72 host genes required for viral infection. Many of these identified genes were also required for infection by two other NS RNA viruses, the lymphocytic choriomeningitis virus of the Arenaviridae family and human parainfluenza virus type 3 of the Paramyxoviridae family. Genes affecting different stages of …

Consensus-Based Reporting Standards For Diagnostic Test Accuracy Studies For Paratuberculosis In Ruminants, Ian A. Gardner, Søren S. Nielsen, Richard J. Wittington, Michael T. Collins, Douwe Bakker, Beth Harris, Srinand Sreevatsan, Jason E. Lombard, Raymond Sweeney, David R. Smith, Jerrie Gavalchin, Shigetoshi Eda

School of Veterinary and Biomedical Sciences: Faculty Publications

The Standards for Reporting of Diagnostic Accuracy (STARD) statement was developed to encourage complete and transparent reporting of key elements of test accuracy studies in human medicine. The statement was motivated by widespread evidence of bias in test accuracy studies and the finding that incomplete or absent reporting of items in the STARD checklist was associated with overly optimistic estimates of test performance characteristics. Although STARD principles apply broadly, specific guidelines do not exist to account for unique considerations in livestock studies such as herd tests, potential use of experimental challenge studies, a more diverse group of testing purposes and …

Regulated Commercial Harvest To Manage Overabundant White-Tailed Deer: An Idea To Consider?, Kurt C. Vercauteren, Charles W. Anderson, Timothy R. Van Deelen, David Drake, W. David Walter, Stephen Vantassel, Scott E. Hygnstrom

United States Department of Agriculture Wildlife Services: Staff Publications

Declines in hunter recruitment coupled with dramatic growth in numbers of white-tailed deer (Odocoileus virginianus) have challenged our ability to manage deer populations through regulated hunting. We review the efficacy of current regulated hunting methods and explain how they are unable to reduce deer numbers sufficiently in some environments. Regulated commercial harvest would provide an additional tool to help state wildlife agencies manage overabundant populations of white-tailed deer. We outline potential means to govern regulated commercial deer harvest and explain how it is compatible with the North American Model of Wildlife Conservation. We identified several benefits, including reduced …

Preliminary Bacterial Study On Subclinical Mastitis And Teat Condition In Dairy Herds Around Shiraz, Masoud Haghkhah, Mohammad Rahim Ahmadi, Hamid Reza Gheisari, Ali Kadivar

Turkish Journal of Veterinary & Animal Sciences

Mastitis is a widely occurring and costly disease in the dairy industry. The aim of this study was to isolate bacterial causes of subclinical mastitis and investigate the relationship between subclinical mastitis and teat condition in dairy herds located around Shiraz, Fars province, Iran. From 7 commercial dairy herds around Shiraz 354 lactating cows were selected randomly. Subclinical mastitis was evaluated by the California Mastitis Test (CMT), electrical conductivity (EC), and somatic cell count (SCC). Teat condition was evaluated by measuring teat width and length. In the 68 samples of bacterial cultures identified, 14 different bacterial species were found. Staphylococcus …

Serological Study Of Leptospirosis Among Dairy Cattle In Bosnia And Herzegovina, Maid Rifatbegovic, Zinka Maksimovic

Turkish Journal of Veterinary & Animal Sciences

A total of 75,206 blood serum samples from dairy cattle and quarantined heifers was collected between 2001 and 2007 and analyzed for bovine leptospirosis by the microscopic agglutination test (MAT). Serovar Hardjo was used for testing of all sera, with the addition of 2 or 3 randomly chosen other serovars (Grippotyphosa, Icterohaemorrhagiae, Pomona, Bataviae, Canicola, and/or Saxcoebing). From the total number of sera tested, 1197 (1.59%) were serologically positive, with a decreasing tendency over the years of research. The most prevalent serovar was Pomona (1.32%), followed by Hardjo (0.52%) and Grippotyphosa (0.37%). The differences among the studied regions in terms …

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 …

Characterization Of The Sero-Reactivity Of Proteins Map1152 And Map1156 From Mycobacterium Avium Subspecies Paratuberculosis, Avery L. Paulson

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Mycobacterium avium subsp. paratuberculosis (MAP) causes Johne’s disease (JD) in ruminants. Development of genetic tools and completion of the MAP genome sequencing project expanded opportunities for antigen discovery. In this thesis, I review the current trends in diagnosis and disease control of JD and present the results of the studies on the seroreactivity of two proteins encoded for by the MAP1152-MAP1156 gene cluster. MAP1152 encodes for a PPE protein and MAP1156 encodes a diacylglycerol acyltransferase involved in triglyceride metabolism and classified in the uncharacterized protein family UPF0089. Maltose-binding protein (MBP) tagged recombinant MAP proteins were purified from Escherichia coli. …

Staphylococcus Aureus Virulence Factors Synthesis Is Controlled By Central Metabolism, Yefei Zhu

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Staphylococcus aureus is a versatile pathogen that can survive in diverse host environments. This versatility depends on its ability to sense nutrients and respond by modulating gene expression, including the synthesis of virulence determinants. In addition to its ability to synthesize virulence factors, the capacity of S. aureus to form biofilms is an important mediator of virulence in certain infections. Biofilms are a complex aggregation of bacteria commonly encapsulated by an adhesive exopolysaccharide matrix (polysaccharide intercellular adhesin; PIA). To study S. aureus biofilm formation, we assessed the metabolic requirements of S. aureus growing in a biofilm and …

Animal Health Matters, David H. Zeman, Russ Daly

Animal Health MATTERS Newsletter

[Page] 1- Olson Agricultural Analytical Services Laboratory Adapts to South Dakota Needs [Page] 2- Director's Message—Service and Grants [Page] 2- Veterinarian Named 2010 SDSU Distinguished Young Alumnus [Page] 3- Diagnostic Implications Following Use of a New IBR-PI3-BRSV Intranasal Vaccine [Page] 3- Extension Vet receives SDVMA Veterinarian of the Year Award [Page] 6- Survey of the Educational Needs of Animal Health Professionals in South Dakota, Summer 2010 [Page] 7- Certificate Program in Veterinary Preventive Medicine Offered Pieces and Parts [Page] 8- Internet Course Offerings from SDSU for Spring 2011 [Page] 8- VBS Department Faculty Members Update Chinese Delegation on Swine Diseases …

Importance Of Wildlife Disease Surveillance, Jerrold L. Belant, Amanda R. Deese

Human–Wildlife Interactions

A commentary on the importance of wildlife disease surveillance.

Animal Health Matters, Jarett Bies, David H. Zeman, Russ Daly

Animal Health MATTERS Newsletter

[Page] 1- New Department Name Introduced in Campus Ceremony [Page] 1- Director's Message: What’s in a Name? [Page] 2- VBS Department Faculty Make Connections in China [Page] 3- ADRDL Personnel Gain Additional Proficiency Training for Foreign Animal Disease Testing, Embark on Test Validation Studies [Page] 3- Veterinary & Biomedical Sciences Department Launches New Website: www.sdstate.edu/vs [Page] 4- Histopathology and the Histology Laboratory at SDSU’s ADRDL Pieces and Parts [Page] 6- Dunn Begins Work as Dean of SDSU College of Agriculture & Biological Sciences [Page] 6- Hennings to Address International Pig Veterinary Society [Page] 6- SDSU Faculty to Co-Author “Diseases of …

Influence Of Type 2 Bovine Viral Diarrhea Virus NPro On Enhancement Of Bovine Respiratory Syncytial Virus Replication Mediated By Antagonism Of Host Cell Interferon Type I Responses, Abdulrahman Abdulaziz A. Alkheraif

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Bovine viral diarrhea virus (BVDV) is a member of the genus Pestivirus, Family Flaviviridae. The virus can infect many species of animals of the order Artiodactyla. The BVDV genome encodes an auto protease, N^pro, that degrades interferon regulatory factor-3 (IRF-3) reducing type I interferon (IFN-I) production from host cells. Bovine respiratory syncytial virus (BRSV) is a member of the genus Pneumovirus, Family Paramyxoviridae. Concurrent infection with BVDV and BRSV causes more severe respiratory and enteric disease than infection with either virus alone. Our hypothesis was that N^pro modulates the innate immune responses to BVDV infection …

The Lack Of An Inherent Membrane Targeting Signal Is Responsible For The Failure Of The Matrix (M1) Protein Of Influenza A Virus To Bud Into Virus-Like Particles, Dan Wang, Aaron Harmon, Jing Jin, David H. Francis, Jane Christopher-Hennings, Eric A. Nelson, Ronald C. Montelaro, Feng Li

Veterinary and Biomedical Sciences Faculty Publications

The matrix protein (M1) of influenza A virus is generally viewed as a key orchestrator in the release of influenza virions from the plasma membrane during infection. In contrast to this model, recent studies have indicated that influenza virus requires expression of the envelope proteins for budding of intracellular M1 into virus particles. Here we explored the mechanisms that control M1 budding. Similarly to previous studies, we found that M1 by itself fails to form virus-like-particles (VLPs). We further demonstrated that M1, in the absence of other viral proteins, was preferentially targeted to the nucleus/perinuclear region rather than to the …

Tactics For Identifying And Eliminating Tritrichomonas Foetus From Infected Beef Herds, Jeff D. Ondrak

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

The protozoan, Tritrichomonas foetus (TF), has been recognized as a cause of bovine infertility for more than 100 years (Skirrow and BonDurant, 1988). As an obligate parasite of the bovine reproductive tract its control and eradication seems achievable (Harding, 1950). However, this disease continues to trouble United States cattle producers and a recent epidemic in the Western US has lead to increased interest in research and regulatory efforts (Cima, 2009). Outbreak investigations were carried out on three Nebraska ranches to assess the efficiency of currently available diagnostic tests, culture, gel polymerase chain reaction (PCR), and real time PCR (rtPCR), in …

Questions And Answers: Bovine Tuberculosis Federal Order

Michigan Bovine Tuberculosis Bibliography and Database

Questions:

What does the Federal Order do?
To whom does the Federal Order apply?
What does the Federal Order mean for me as a producer in an accredited free State/zone?
What does the Federal Order mean for me as a producer in a modified accredited advanced State/ zone?
What does the Federal Order mean for me as a producer in a modified accredited, accreditation preparatory, or nonaccredited State/zone?
What does the Federal Order mean for me as a producer in a modified accredited, accreditation preparatory, or nonaccredited State/zone?
When does the Federal Order take effect?
How long does the Federal …

Animal Health Matters, Russ Daly, David H. Zeman

Animal Health MATTERS Newsletter

[Page] 1- Iraqi Veterinarian Brings Veterinary-and Life-Experiences to ADRDL [Page] 2- Director's Message — Tomorrow’s Veterinarians and the NAVMEC [Page] 2- Veterinarians with Current USDA Accreditation: Note Program Changes [Page] 4- The Virology Section at SDSU’s ADRDL [Page] 5- Fish Health and Diagnostics Update Pieces and Parts [Page] 6- VSD Faculty Members Honored at SDSU Faculty Recognition Event [Page] 6- ADRDL Assists AIB in Bovine Tuberculosis Diagnostics [Page] 6- 2010 Bailey Herd Health Conference a Success [Page] 6- Faculty Members Attend “Animal Welfare in Veterinary Education and Research” Symposium [Page] 7- Calf Scours Submission Reminders [Page] 7- Calendar of Events

Role Of All Of The Prrsv Glycoproteins In Protective Immune Response, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

Porcine reproductive and respiratory syndrome virus (PRRSV) contains the major glycoprotein, GP5, as well as three other minor glycoproteins, namely, GP2a, GP3, and GP4, on the virion envelope, all of which are required for generation of infectious virions. To study their interactions amongst each other and with the cellular receptor for PRRSV, we have cloned each of the viral glycoproteins and CD163 receptor in expression vectors and examined their expression and interaction with each other in transfected cells by co-immunoprecipitation (co-IP) assay using monospecific antibodies. Our results show that strong interaction exists between GP4 and GP5 proteins, although weak interactions …

Cell-Type Specific Distribution Of Chloride Transporters In The Rat Suprachiasmatic Nucleus, Michael A. Belenky, Patricia J. Sollars, David B. Mount, Seth L. Alper, Yosef Yarom, Gary E. Pickard

School of Veterinary and Biomedical Sciences: Faculty Publications

The suprachiasmatic nucleus (SCN) is a circadian oscillator and biological clock. Cell-to-cell communication is important for synchronization among SCN neuronal oscillators and the great majority of SCN neurons use γ-aminobutyric acid (GABA) as a neurotransmitter, the principal inhibitory neurotransmitter in the adult central nervous system. Acting via the ionotropic GABAA receptor, a chloride ion channel, GABA typically evokes inhibitory responses in neurons via Cl− influx. Within the SCN GABA evokes both inhibitory and excitatory responses although the mechanism underlying GABA-evoked excitation in the SCN is unknown. GABA-evoked depolarization in immature neurons in several regions of the brain is a function …