DOCSLIB.ORG

Poster Session II Cntnap2a and 2B Knockouts

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Poster Session II Cntnap2a and 2B Knockouts Neuropsychopharmacology (2011) 36, S198–S323 & 2011 American College of Neuropsychopharmacology. All rights reserved 0893-133X/11 S198 www.neuropsychopharmacology.org Poster Session II CNTNAP2a and 2b knockouts. These mutations are predicted to be Tuesday, December 6, 2011 5:30 PM – 7:30 PM damaging as they occur early in the coding regions of each gene and produce a frameshift, resulting in a premature stop codon and truncation of the protein in or immediately after the 1. A Zebrafish Model for the Functional Analysis of Genes in N-terminal discoidin domain. In total, we have successfully Autism generated zebrafish founders with deleterious germline mutations Ellen J. Hoffman*, Antonio Giraldez, Matthew State in both CNTNAP2 paralogs. We are currently conducting a battery of morphological and behavioral assays to identify quantifiable Yale University, New Haven, USA phenotypes in CNS structure and larval neural circuits in mutant fish. Discussion: Our experiments lay the foundation for the use of Background: A critical challenge in the genetics of neuropsychia- zebrafish as a model system for elucidating the function of tric disorders is distinguishing deleterious rare mutations from susceptibility genes in ASD. We have identified the zebrafish neutral variants, as rare sequence and structural variants have orthologs of the ASD susceptibility gene, CNTNAP2, demonstrated been identified throughout the genomes of both affected and its expression in the zebrafish CNS, and successfully generated unaffected individuals, including at candidate gene loci. The ability the first ZFN-induced deletions in each CNTNAP2 paralog. This to distinguish rare functional from rare neutral variation is critical model has tremendous promise for illuminating common path- for confirming the association of risk genes carrying rare alleles. ways involving ASD susceptibility genes and rapidly assessing the For this reason, we propose to develop an in vivo model that will functional consequences of rare sequence variation in a risk gene. allow us rapidly to differentiate mutations that alter the function Future applications of this research include large-scale pharma- of susceptibility genes from neutral rare variants. This novel cological screens to identify novel therapeutic targets aimed at the approach capitalizes on critical advantages of zebrafish, including mechanisms underlying the core deficits of ASD. visualization of the developing nervous system in transparent Disclosure: E. Hoffman: none. A. Giraldez: none. M. State: none. embryos, ease of genetic manipulation, and large progenies that facilitate the conduct of large-scale pharmacologic screens. Therefore, we generated zebrafish knockouts of the ASD risk gene, CNTNAP2, using the emerging technology of zinc finger nucleases (ZFN). We anticipate that CNTNAP2 will be particularly 2. Histidine Decarboxylase Deficiency produces Tourette informative in this regard, as homozygous disruption of CNTNAP2 Syndrome Phenomenology and Dopamine Dysregulation in by a single base pair deletion in the Old Order Amish population Humans and Mice Lissandra C. Baldan Ramsey, Kyle Williams, Jean-Dominique causes a monogenic syndrome that is highly associated with ASD. Gallezot, Michael Crowley, George Anderson, Bennett L. Leventhal, In addition, the State laboratory identified a de novo chromosome Hiroshi Ohtsu, John H. Krystal, Linda Mayes, Ivan de Araujo, 7q inversion disrupting CNTNAP2 in a child with cognitive and Yu-Shin Ding, Matthew W. State, Christopher Pittenger* social delay. Our goals in developing this model are: 1) to leverage any distinctive reproducible and quantifiable phenotype for Yale University, New Haven, USA forward genetic studies that will help to elaborate conserved molecular mechanisms and pathways involving these susceptibility Background: Tourette syndrome (TS) is a neurodevelopmental genes; and 2) to test the relative ability of the wild type human gene disorder characterized by tics and sensory gating abnormalities. compared to constructs containing rare mutations identified in Available treatments are limited, and its neurobiological under- affected and unaffected individuals to rescue the identified pinnings are not well understood. Pathophysiological analysis of phenotype. such conditions in animal models can provide key insight; Methods: We identified the zebrafish orthologs of the human however, modeling complex neuropsychiatric conditions presents CNTNAP2 gene by conducting a search of the zebrafish genome daunting challenges. TS has a heritability of 30-60%, but causative (Zv7) in the National Center for Biotechnology Information mutations and risk alleles have proven elusive, attesting to a (NCBI) database. We analyzed the expression patterns of these complex, heterogeneous genetic architecture. In this setting, the paralogs in zebrafish embryos at 30 and 48 hours post fertilization investigation of rare, highly penetrant mutations is of particular by in situ hybridization. We utilized ZFN directed against exons 2 value. A recent study of a dense 2-generation TS pedigree and 3 of CNTNAP2a and CNTNAP2b, respectively, to generate identified a rare segregating nonsense mutation, Hdc W317X, in targeted germline deletions in each gene. Founders were generated the l-histidine decarboxylase (Hdc) gene (Ercan –Sencicek et al., by injecting mRNA encoding ZFN (Sigma-Aldrich) targeting either NEJM 2010). The causal connection between a reduction in HDC CNTNAP2a or 2b into embryos at the one-cell stage. Founders were activity and the symptoms of TS remains unclear. Here we analyze identified by screening the progeny of incrosses of ZFN-injected mice lacking one or both copies of the Hdc gene and TS patients adult fish by PCR followed by high-resolution fragment analysis. carrying the Hdc W317X mutation to establish that reduction in Founders were outcrossed to wild-type fish, and the heterozygous histamine (HA) biosynthesis produces key phenomenological and CNTNAP2a and 2b knockouts were incrossed to generate viable neurochemical features of TS. homozygous knockouts. Methods: 9 TS patients carrying the Hdc W317X mutation were Results: We identified two zebrafish orthologs of CNTNAP2, characterized clinically and in prepulse inhibition (PPI). Adult CNTNAP2a and 2b. In situ analysis of these transcripts between male HDC knockout mice, backcrossed multiple generations onto 30 and 48 hours after fertilization revealed expression of both the C57Bl/6 genetic background, were tested in parallel behavioral paralogs in the CNS, predominantly in the midbrain and assays (stereotypy; PPI). Striatal dopamine in knockout mice was hindbrain. These paralogs demonstrate distinct yet partially assessed by in vivo microdialysis. Dopamine D2/D3 receptors were overlapping expression patterns. Utilizing ZFN targeting each quantified in vivo in patients carrying the Hdc W317X mutation by gene, we generated multiple zebrafish founders with deleterious positron emission tomography (PET) with the D3-preferring germline mutations in both CNTNAP2a and 2b and outcrossed ligand PHNO, and in vitro in mice using the D2/D3 ligand these founders to wild-type fish, producing viable heterozygous raclopride. ACNP 50th Annual Meeting Abstracts S199 Results: All patients carrying the Hdc W317X mutation had current we hypothesized that they may also have poor attentional control. and/or past tics; patients also had a deficit in auditory PPI, as has Indeed, impulsivity may be conceptualized as a consequence of such been shown in TS more generally. Heterozygous and homozygous poor top-down control of attention. We therefore characterized the knockout mice had reduced brain histamine and exhibited parallel attentional capacities of STs and GTs using our translational behavioral symptomatology, with enhanced stereotypy after Sustained Attention Task (SAT; e.g., Demeter et al., 2008, 2011). amphetamine administration and a deficit in PPI. Mice showed Methods: Sprague-Dawley rats were screened using a Pavlovian increased dopamine in the dorsal striatum during the active (dark) Conditioned Approach (PCA) procedure and designated STs or phase of the circadian cycle, when histamine was high in wild-type GTs, as described previously (e.g., Lovic et al., 2011). Animals were controls. Both patients and mice showed an elevation in D2/D3 then trained on the SAT (see Demeter et al., 2008). This task receptor binding in the substantia nigra; this is consistent with the consists of random sequences of unpredictably occurring visual upregulation of D3 receptors in this structure seen in other signals of variable duration as well as trials during which no signal is contexts after chronic dopamine elevation. presented (blanks). Following a signal or non-signal event two levers Discussion: Parallel behavioral abnormalities in patients and mice are extended into the chambers for 4 sec, and subjects report the establish a casual link between disruption of the Hdc gene and presence or absence of a signal by pressing the appropriate lever. TS-like behavioral abnormalities, validating the unexpected connec- Hits and correct rejections are rewarded while misses and false tion first revealed by genetic linkage in a single family. Dysregulation alarms trigger a variable intertrial interval. Daily sessions lasted of striatal dopamine represents a plausible pathophysiological link 64 min and consisted of approximately 318 trials total. Animals were between histamine deficiency and functional abnormalities in the extensively trained until their performance
Load more

Recommended publications
  • Infiltrating Myeloid Cells Drive Osteosarcoma Progression Via GRM4 Regulation of IL23
    Published OnlineFirst September 16, 2019; DOI: 10.1158/2159-8290.CD-19-0154 RESEARCH BRIEF Infi ltrating Myeloid Cells Drive Osteosarcoma Progression via GRM4 Regulation of IL23 Maya Kansara 1 , 2 , Kristian Thomson 1 , Puiyi Pang 1 , Aurelie Dutour 3 , Lisa Mirabello 4 , Francine Acher5 , Jean-Philippe Pin 6 , Elizabeth G. Demicco 7 , Juming Yan 8 , Michele W.L. Teng 8 , Mark J. Smyth 9 , and David M. Thomas 1 , 2 ABSTRACT The glutamate metabotropic receptor 4 (GRM4 ) locus is linked to susceptibility to human osteosarcoma, through unknown mechanisms. We show that Grm4 − / − gene– targeted mice demonstrate accelerated radiation-induced tumor development to an extent comparable with Rb1 +/ − mice. GRM4 is expressed in myeloid cells, selectively regulating expression of IL23 and the related cytokine IL12. Osteosarcoma-conditioned media induce myeloid cell Il23 expression in a GRM4-dependent fashion, while suppressing the related cytokine Il12 . Both human and mouse osteosarcomas express an increased IL23:IL12 ratio, whereas higher IL23 expression is associated with worse survival in humans. Con- sistent with an oncogenic role, Il23−/− mice are strikingly resistant to osteosarcoma development. Agonists of GRM4 or a neutralizing antibody to IL23 suppressed osteosarcoma growth in mice. These fi ndings identify a novel, druggable myeloid suppressor pathway linking GRM4 to the proinfl ammatory IL23/IL12 axis. SIGNIFICANCE: Few novel systemic therapies targeting osteosarcoma have emerged in the last four decades. Using insights gained from a genome-wide association study and mouse modeling, we show that GRM4 plays a role in driving osteosarcoma via a non–cell-autonomous mechanism regulating IL23, opening new avenues for therapeutic intervention.
    [Show full text]
  • Metabotropic Glutamate Receptors
    mGluR Metabotropic glutamate receptors mGluR (metabotropic glutamate receptor) is a type of glutamate receptor that are active through an indirect metabotropic process. They are members of thegroup C family of G-protein-coupled receptors, or GPCRs. Like all glutamate receptors, mGluRs bind with glutamate, an amino acid that functions as an excitatoryneurotransmitter. The mGluRs perform a variety of functions in the central and peripheral nervous systems: mGluRs are involved in learning, memory, anxiety, and the perception of pain. mGluRs are found in pre- and postsynaptic neurons in synapses of the hippocampus, cerebellum, and the cerebral cortex, as well as other parts of the brain and in peripheral tissues. Eight different types of mGluRs, labeled mGluR1 to mGluR8, are divided into groups I, II, and III. Receptor types are grouped based on receptor structure and physiological activity. www.MedChemExpress.com 1 mGluR Agonists, Antagonists, Inhibitors, Modulators & Activators (-)-Camphoric acid (1R,2S)-VU0155041 Cat. No.: HY-122808 Cat. No.: HY-14417A (-)-Camphoric acid is the less active enantiomer (1R,2S)-VU0155041, Cis regioisomer of VU0155041, is of Camphoric acid. Camphoric acid stimulates a partial mGluR4 agonist with an EC50 of 2.35 osteoblast differentiation and induces μM. glutamate receptor expression. Camphoric acid also significantly induced the activation of NF-κB and AP-1. Purity: ≥98.0% Purity: ≥98.0% Clinical Data: No Development Reported Clinical Data: No Development Reported Size: 10 mM × 1 mL, 100 mg Size: 10 mM × 1 mL, 5 mg, 10 mg, 25 mg (2R,4R)-APDC (R)-ADX-47273 Cat. No.: HY-102091 Cat. No.: HY-13058B (2R,4R)-APDC is a selective group II metabotropic (R)-ADX-47273 is a potent mGluR5 positive glutamate receptors (mGluRs) agonist.
    [Show full text]
  • Performance Enhancement at the Cost of Potential Brain Plasticity: Neural Ramifications of Nootropic Drugs in the Healthy Developing Brain
    REVIEW ARTICLE published: 13 May 2014 SYSTEMS NEUROSCIENCE doi: 10.3389/fnsys.2014.00038 Performance enhancement at the cost of potential brain plasticity: neural ramifications of nootropic drugs in the healthy developing brain Kimberly R. Urban 1 and Wen-Jun Gao 2* 1 Department of Psychology, University of Delaware, Newark, DE, USA 2 Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA Edited by: Cognitive enhancement is perhaps one of the most intriguing and controversial Mikhail Lebedev, Duke University, topics in neuroscience today. Currently, the main classes of drugs used as potential USA cognitive enhancers include psychostimulants (methylphenidate (MPH), amphetamine), Reviewed by: Kimberly Simpson, University of but wakefulness-promoting agents (modafinil) and glutamate activators (ampakine) are Mississippi Medical Center, USA also frequently used. Pharmacologically, substances that enhance the components Christopher R. Madan, University of of the memory/learning circuits—dopamine, glutamate (neuronal excitation), and/or Alberta, Canada norepinephrine—stand to improve brain function in healthy individuals beyond their *Correspondence: baseline functioning. In particular, non-medical use of prescription stimulants such as Wen-Jun Gao, Department of Neurobiology and Anatomy, Drexel MPH and illicit use of psychostimulants for cognitive enhancement have seen a recent University College of Medicine, rise among teens and young adults in schools and college campuses. However, this 2900 Queen Lane, Philadelphia, PA enhancement likely comes with a neuronal, as well as ethical, cost. Altering glutamate 19129, USA function via the use of psychostimulants may impair behavioral flexibility, leading to e-mail: [email protected] the development and/or potentiation of addictive behaviors. Furthermore, dopamine and norepinephrine do not display linear effects; instead, their modulation of cognitive and neuronal function maps on an inverted-U curve.
    [Show full text]
  • General Anesthesia and Altered States of Arousal: a Systems Neuroscience Analysis
    General Anesthesia and Altered States of Arousal: A Systems Neuroscience Analysis The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. Citation Brown, Emery N., Patrick L. Purdon, and Christa J. Van Dort. “General Anesthesia and Altered States of Arousal: A Systems Neuroscience Analysis.” Annual Review of Neuroscience 34, no. 1 (July 21, 2011): 601–628. As Published http://dx.doi.org/10.1146/annurev-neuro-060909-153200 Publisher Annual Reviews Version Author's final manuscript Citable link http://hdl.handle.net/1721.1/86331 Terms of Use Creative Commons Attribution-Noncommercial-Share Alike Detailed Terms http://creativecommons.org/licenses/by-nc-sa/4.0/ NIH Public Access Author Manuscript Annu Rev Neurosci. Author manuscript; available in PMC 2012 July 06. NIH-PA Author ManuscriptPublished NIH-PA Author Manuscript in final edited NIH-PA Author Manuscript form as: Annu Rev Neurosci. 2011 ; 34: 601–628. doi:10.1146/annurev-neuro-060909-153200. General Anesthesia and Altered States of Arousal: A Systems Neuroscience Analysis Emery N. Brown1,2,3, Patrick L. Purdon1,2, and Christa J. Van Dort1,2 Emery N. Brown: [email protected]; Patrick L. Purdon: [email protected]; Christa J. Van Dort: [email protected] 1Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114 2Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 3Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 Abstract Placing a patient in a state of general anesthesia is crucial for safely and humanely performing most surgical and many nonsurgical procedures.
    [Show full text]
  • Effect of Dextromethorphan-Quinidine on Agitation in Patients with Alzheimer Disease Dementia a Randomized Clinical Trial
    Research Original Investigation Effect of Dextromethorphan-Quinidine on Agitation in Patients With Alzheimer Disease Dementia A Randomized Clinical Trial Jeffrey L. Cummings, MD, ScD; Constantine G. Lyketsos, MD, MHS; Elaine R. Peskind, MD; Anton P. Porsteinsson, MD; Jacobo E. Mintzer, MD, MBA; Douglas W. Scharre, MD; Jose E. De La Gandara, MD; Marc Agronin, MD; Charles S. Davis, PhD; Uyen Nguyen, BS; Paul Shin, MS; Pierre N. Tariot, MD; João Siffert, MD Editorial page 1233 IMPORTANCE Agitation is common among patients with Alzheimer disease; safe, effective Author Video Interview and treatments are lacking. JAMA Report Video at jama.com OBJECTIVE To assess the efficacy, safety, and tolerability of dextromethorphan Supplemental content at hydrobromide–quinidine sulfate for Alzheimer disease–related agitation. jama.com DESIGN, SETTING, AND PARTICIPANTS Phase 2 randomized, multicenter, double-blind, CME Quiz at jamanetworkcme.com and placebo-controlled trial using a sequential parallel comparison design with 2 consecutive CME Questions page 1286 5-week treatment stages conducted August 2012–August 2014. Patients with probable Alzheimer disease, clinically significant agitation (Clinical Global Impressions–Severity agitation score Ն4), and a Mini-Mental State Examination score of 8 to 28 participated at 42 US study sites. Stable dosages of antidepressants, antipsychotics, hypnotics, and antidementia medications were allowed. INTERVENTIONS In stage 1, 220 patients were randomized in a 3:4 ratio to receive dextromethorphan-quinidine (n = 93) or placebo (n = 127). In stage 2, patients receiving dextromethorphan-quinidine continued; those receiving placebo were stratified by response and rerandomized in a 1:1 ratio to dextromethorphan-quinidine (n = 59) or placebo (n = 60).
    [Show full text]
  • WO 2016/001643 Al 7 January 2016 (07.01.2016) P O P C T
    (12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (19) World Intellectual Property Organization International Bureau (10) International Publication Number (43) International Publication Date WO 2016/001643 Al 7 January 2016 (07.01.2016) P O P C T (51) International Patent Classification: (74) Agents: GILL JENNINGS & EVERY LLP et al; The A61P 25/28 (2006.01) A61K 31/194 (2006.01) Broadgate Tower, 20 Primrose Street, London EC2A 2ES A61P 25/16 (2006.01) A61K 31/205 (2006.01) (GB). A23L 1/30 (2006.01) (81) Designated States (unless otherwise indicated, for every (21) International Application Number: kind of national protection available): AE, AG, AL, AM, PCT/GB20 15/05 1898 AO, AT, AU, AZ, BA, BB, BG, BH, BN, BR, BW, BY, BZ, CA, CH, CL, CN, CO, CR, CU, CZ, DE, DK, DM, (22) International Filing Date: DO, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT, 29 June 2015 (29.06.2015) HN, HR, HU, ID, IL, IN, IR, IS, JP, KE, KG, KN, KP, KR, (25) Filing Language: English KZ, LA, LC, LK, LR, LS, LU, LY, MA, MD, ME, MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI, NO, NZ, OM, (26) Publication Language: English PA, PE, PG, PH, PL, PT, QA, RO, RS, RU, RW, SA, SC, (30) Priority Data: SD, SE, SG, SK, SL, SM, ST, SV, SY, TH, TJ, TM, TN, 141 1570.3 30 June 2014 (30.06.2014) GB TR, TT, TZ, UA, UG, US, UZ, VC, VN, ZA, ZM, ZW. 1412414.3 11 July 2014 ( 11.07.2014) GB (84) Designated States (unless otherwise indicated, for every (71) Applicant: MITOCHONDRIAL SUBSTRATE INVEN¬ kind of regional protection available): ARIPO (BW, GH, TION LIMITED [GB/GB]; 39 Glasslyn Road, London GM, KE, LR, LS, MW, MZ, NA, RW, SD, SL, ST, SZ, N8 8RJ (GB).
    [Show full text]
  • Ampakines Potentiate the Corticostriatal Pathway to Reduce Acute and Chronic Pain Fei Zeng1,2, Qiaosheng Zhang2, Yaling Liu2, Guanghao Sun2, Anna Li2, Robert S
    Zeng et al. Mol Brain (2021) 14:45 https://doi.org/10.1186/s13041-021-00757-y RESEARCH Open Access AMPAkines potentiate the corticostriatal pathway to reduce acute and chronic pain Fei Zeng1,2, Qiaosheng Zhang2, Yaling Liu2, Guanghao Sun2, Anna Li2, Robert S. Talay2 and Jing Wang2,3* Abstract The corticostriatal circuit plays an important role in the regulation of reward- and aversion-types of behaviors. Specif- cally, the projection from the prelimbic cortex (PL) to the nucleus accumbens (NAc) has been shown to regulate sensory and afective aspects of pain in a number of rodent models. Previous studies have shown that enhancement of glutamate signaling through the NAc by AMPAkines, a class of agents that specifcally potentiate the function of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, reduces acute and persistent pain. How- ever, it is not known whether postsynaptic potentiation of the NAc with these agents can achieve the full anti-noci- ceptive efects of PL activation. Here we compared the impact of AMPAkine treatment in the NAc with optogenetic activation of the PL on pain behaviors in rats. We found that not only does AMPAkine treatment partially reconstitute the PL inhibition of sensory withdrawals, it fully occludes the efect of the PL on reducing the aversive component of pain. These results indicate that the NAc is likely one of the key targets for the PL, especially in the regulation of pain aversion. Furthermore, our results lend support for neuromodulation or pharmacological activation of the corticostri- atal circuit as an important analgesic approach.
    [Show full text]
  • Development of Allosteric Modulators of Gpcrs for Treatment of CNS Disorders Hilary Highfield Nickols A, P
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Neurobiology of Disease 61 (2014) 55–71 Contents lists available at ScienceDirect Neurobiology of Disease journal homepage: www.elsevier.com/locate/ynbdi Review Development of allosteric modulators of GPCRs for treatment of CNS disorders Hilary Highfield Nickols a, P. Jeffrey Conn b,⁎ a Division of Neuropathology, Department of Pathology, Microbiology and Immunology, Vanderbilt University, USA b Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA article info abstract Article history: The discovery of allosteric modulators of G protein-coupled receptors (GPCRs) provides a promising new strategy Received 25 July 2013 with potential for developing novel treatments for a variety of central nervous system (CNS) disorders. Tradition- Revised 13 September 2013 al drug discovery efforts targeting GPCRs have focused on developing ligands for orthosteric sites which bind en- Accepted 17 September 2013 dogenous ligands. Allosteric modulators target a site separate from the orthosteric site to modulate receptor Available online 27 September 2013 function. These allosteric agents can either potentiate (positive allosteric modulator, PAM) or inhibit (negative allosteric modulator, NAM) the receptor response and often provide much greater subtype selectivity than Keywords: Allosteric modulator orthosteric ligands for the same receptors. Experimental evidence has revealed more nuanced pharmacological CNS modes of action of allosteric modulators, with some PAMs showing allosteric agonism in combination with pos- Drug discovery itive allosteric modulation in response to endogenous ligand (ago-potentiators) as well as “bitopic” ligands that GPCR interact with both the allosteric and orthosteric sites. Drugs targeting the allosteric site allow for increased drug Metabotropic glutamate receptor selectivity and potentially decreased adverse side effects.
    [Show full text]
  • Optogenetic Stimulation of Prefrontal Glutamatergic Neurons Enhances Recognition Memory
    4930 • The Journal of Neuroscience, May 4, 2016 • 36(18):4930–4939 Behavioral/Cognitive Optogenetic Stimulation of Prefrontal Glutamatergic Neurons Enhances Recognition Memory Abigail Benn, Gareth R. I. Barker, Sarah A. Stuart, XEva v. L. Roloff, XAnja G. Teschemacher, E. Clea Warburton, and Emma S. J. Robinson School of Physiology, Pharmacology, and Neuroscience, Faculty of Biomedical Sciences, University of Bristol, Bristol BS8 1TD, United Kingdom Finding effective cognitive enhancers is a major health challenge; however, modulating glutamatergic neurotransmission has the poten- tial to enhance performance in recognition memory tasks. Previous studies using glutamate receptor antagonists have revealed that the medial prefrontal cortex (mPFC) plays a central role in associative recognition memory. The present study investigates short-term recognition memory using optogenetics to target glutamatergic neurons within the rodent mPFC specifically. Selective stimulation of glutamatergic neurons during the online maintenance of information enhanced associative recognition memory in normal animals. This cognitive enhancing effect was replicated by local infusions of the AMPAkine CX516, but not CX546, which differ in their effects on EPSPs. This suggests that enhancing the amplitude, but not the duration, of excitatory synaptic currents improves memory performance. Increasing glutamate release through infusions of the mGluR7 presynaptic receptor antagonist MMPIP had no effect on performance. Key words: AMPAkine; optogenetics; prefrontal cortex; rat; recognition memory Significance Statement These results provide new mechanistic information that could guide the targeting of future cognitive enhancers. Our work suggests that improved associative-recognition memory can be achieved by enhancing endogenous glutamatergic neuronal ac- tivity selectively using an optogenetic approach. We build on these observations to recapitulate this effect using drug treatments thatenhancetheamplitudeofEPSPs;however,drugsthatalterthedurationoftheEPSPorincreaseglutamatereleaselackefficacy.
    [Show full text]
  • GPCR/G Protein
    Inhibitors, Agonists, Screening Libraries www.MedChemExpress.com GPCR/G Protein G Protein Coupled Receptors (GPCRs) perceive many extracellular signals and transduce them to heterotrimeric G proteins, which further transduce these signals intracellular to appropriate downstream effectors and thereby play an important role in various signaling pathways. G proteins are specialized proteins with the ability to bind the nucleotides guanosine triphosphate (GTP) and guanosine diphosphate (GDP). In unstimulated cells, the state of G alpha is defined by its interaction with GDP, G beta-gamma, and a GPCR. Upon receptor stimulation by a ligand, G alpha dissociates from the receptor and G beta-gamma, and GTP is exchanged for the bound GDP, which leads to G alpha activation. G alpha then goes on to activate other molecules in the cell. These effects include activating the MAPK and PI3K pathways, as well as inhibition of the Na+/H+ exchanger in the plasma membrane, and the lowering of intracellular Ca2+ levels. Most human GPCRs can be grouped into five main families named; Glutamate, Rhodopsin, Adhesion, Frizzled/Taste2, and Secretin, forming the GRAFS classification system. A series of studies showed that aberrant GPCR Signaling including those for GPCR-PCa, PSGR2, CaSR, GPR30, and GPR39 are associated with tumorigenesis or metastasis, thus interfering with these receptors and their downstream targets might provide an opportunity for the development of new strategies for cancer diagnosis, prevention and treatment. At present, modulators of GPCRs form a key area for the pharmaceutical industry, representing approximately 27% of all FDA-approved drugs. References: [1] Moreira IS. Biochim Biophys Acta. 2014 Jan;1840(1):16-33.
    [Show full text]
  • Diamandis Thesis
    !"!#$ CHEMICAL GENETIC INTERROGATION OF NEURAL STEM CELLS: PHENOTYPE AND FUNCTION OF NEUROTRANSMITTER PATHWAYS IN NORMAL AND BRAIN TUMOUR INITIATING NEURAL PRECUSOR CELLS by Phedias Diamandis A thesis submitted in conformity with the requirements for the degree of Doctor of Philosophy. Department of Molecular Genetics University of Toronto © Copyright by Phedias Diamandis 2010 Phenotype and Function of Neurotransmitter Pathways in Normal and Brain Tumor Initiating Neural Precursor Cells Phedias Diamandis Doctor of Philosophy Department of Molecular Genetics University of Toronto 2010 &'(!)&*!% The identification of self-renewing and multipotent neural stem cells (NSCs) in the mammalian brain brings promise for the treatment of neurological diseases and has yielded new insight into brain cancer. The complete repertoire of signaling pathways that governs these cells however remains largely uncharacterized. This thesis describes how chemical genetic approaches can be used to probe and better define the operational circuitry of the NSC. I describe the development of a small molecule chemical genetic screen of NSCs that uncovered an unappreciated precursor role of a number of neurotransmitter pathways commonly thought to operate primarily in the mature central nervous system (CNS). Given the similarities between stem cells and cancer, I then translated this knowledge to demonstrate that these neurotransmitter regulatory effects are also conserved within cultures of cancer stem cells. I then provide experimental and epidemiologically support for this hypothesis and suggest that neurotransmitter signals may also regulate the expansion of precursor cells that drive tumor growth in the brain. Specifically, I first evaluate the effects of neurochemicals in mouse models of brain tumors. I then outline a retrospective meta-analysis of brain tumor incidence rates in psychiatric patients presumed to be chronically taking neuromodulators similar to those identified in the initial screen.
    [Show full text]
  • ()-PHCCC, a Positive Allosteric Modulator of Mglur4
    Neuropharmacology 45 (2003) 895–906 www.elsevier.com/locate/neuropharm (Ϫ)-PHCCC, a positive allosteric modulator of mGluR4: characterization, mechanism of action, and neuroprotection M. Maj a,1, V. Bruno b,1, Z. Dragic a, R. Yamamoto a, G. Battaglia b, W. Inderbitzin a, N. Stoehr a, T. Stein a, F. Gasparini a, I. Vranesic a, R. Kuhn a, F. Nicoletti b,c, P.J. Flor a,∗ a Novartis Institutes for BioMedical Research, Neuroscience Disease Area, WKL-125.6.08, Basel CH-4002, Switzerland b Istituto Neurologico Mediterraneo, Neuromed, Pozzilli, Italy c Department of Human Physiology and Pharmacology, University of Rome, Rome, Italy Received 25 February 2003; received in revised form 27 May 2003; accepted 23 June 2003 Abstract Group-III metabotropic glutamate receptors (mGluR4, -6, -7, and -8) modulate neurotoxicity of excitatory amino acids and beta- amyloid-peptide (bAP), as well as epileptic convulsions, most likely via presynaptic inhibition of glutamatergic neurotransmission. Due to the lack of subtype-selective ligands for group-III receptors, we previously utilized knock-out mice to identify mGluR4 as + the primary receptor mediating neuroprotection of unselective group-III agonists such as L-AP4 or ( )-PPG, whereas mGluR7 is critical for anticonvulsive effects. In a recent effort to find group-III subtype-selective drugs we identified (+/Ϫ)-PHCCC as a positive allosteric modulator for mGluR4. This compound increases agonist potency and markedly enhances maximum efficacy and, at higher concentrations, directly activates mGluR4 with low efficacy. All the activity of (+/Ϫ)-PHCCC resides in the (Ϫ)-enantiomer, which is inactive at mGluR2, -3, -5a, -6, -7b and -8a, but shows partial antagonist activity at mGluR1b (30% maximum antagonist efficacy).
    [Show full text]