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1.
Phys Rev Lett ; 131(8): 082502, 2023 Aug 25.
Article in English | MEDLINE | ID: mdl-37683153

ABSTRACT

We present an apparatus for detection of cyclotron radiation yielding a frequency-based ß^{±} kinetic energy determination in the 5 keV to 2.1 MeV range, characteristic of nuclear ß decays. The cyclotron frequency of the radiating ß particles in a magnetic field is used to determine the ß energy precisely. Our work establishes the foundation to apply the cyclotron radiation emission spectroscopy (CRES) technique, developed by the Project 8 Collaboration, far beyond the 18-keV tritium endpoint region. We report initial measurements of ß^{-}'s from ^{6}He and ß^{+}'s from ^{19}Ne decays to demonstrate the broadband response of our detection system and assess potential systematic uncertainties for ß spectroscopy over the full (MeV) energy range. To our knowledge, this is the first direct observation of cyclotron radiation from individual highly relativistic ß's in a waveguide. This work establishes the application of CRES to a variety of nuclei, opening its reach to searches for new physics beyond the TeV scale via precision ß-decay measurements.

2.
Phys Rev Lett ; 129(18): 182502, 2022 Oct 28.
Article in English | MEDLINE | ID: mdl-36374704

ABSTRACT

We report the first precise measurement of a ß-recoil correlation from a radioactive noble gas (^{6}He) confined via a magneto-optical trap. The measurement is motivated by the search for exotic tensor-type contributions to the charged weak current. Interpreted as tensor currents with right-handed neutrinos, the measurements yield |C_{T}/C_{A}|^{2}≤0.022 (90% confidence limit, C.L.). On the other hand, for left-handed neutrinos the limits are 0.007

3.
Hum Reprod ; 36(1): 40-47, 2021 01 01.
Article in English | MEDLINE | ID: mdl-33145598

ABSTRACT

STUDY QUESTION: Does maternal infection with severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) in first trimester pregnancy have an impact on the fetal development as measured by nuchal translucency thickness and pregnancy loss? SUMMARY ANSWER: Nuchal translucency thickness at the first trimester scan was not significantly different in pregnant women with versus without SARS-CoV-2 infection in early pregnancy and there was no significantly increased risk of pregnancy loss in women with SARS-CoV-2 infection in the first trimester. WHAT IS KNOWN ALREADY: Pregnant women are more vulnerable to viral infections. Previous coronavirus epidemics have been associated with increased maternal morbidity, mortality and adverse obstetric outcomes. Currently, no evidence exists regarding possible effects of SARS-CoV-2 in first trimester pregnancies. STUDY DESIGN, SIZE, DURATION: Cohort study of 1019 women with a double test taken between 17 February and 23 April 2020, as a part of the combined first trimester risk assessment, and 36 women with a first trimester pregnancy loss between 14 April and 21 May 2020, prior to the double test. The study period was during the first SARS-CoV-2 epidemic wave in Denmark. PARTICIPANTS/MATERIALS, SETTING, METHODS: Cohort 1 included pregnant women with a double test taken within the study period. The excess serum from each double test was analyzed for SARS-CoV-2 antibodies. Results were correlated to the nuchal translucency thickness and the number of pregnancy losses before or at the time of the first trimester scan. Cohort 2 included women with a pregnancy loss before the gestational age for double test sample. Serum from a blood test taken the day the pregnancy loss was identified was analyzed for SARS-CoV-2 antibodies. The study was conducted at a public university hospital serving ∼12% of pregnant women and births in Denmark. All participants in the study provided written informed consent. MAIN RESULTS AND THE ROLE OF CHANCE: Eighteen (1.8%) women had SARS-CoV-2 antibodies in the serum from the double test suggestive of SARS-CoV-2 infection in early pregnancy. There was no significant difference in nuchal translucency thickness for women testing positive for previous SARS-CoV-2 infection (n = 16) versus negative (n = 966) (P = 0.62). There was no significantly increased risk of pregnancy loss for women with antibodies (n = 1) (OR 3.4, 0.08-24.3 95% CI, P = 0.27). None of the women had been hospitalized due to SARS-CoV-2 infection. None of the women with pregnancy loss prior to the double test (Cohort 2) had SARS-CoV-2 antibodies. LIMITATIONS, REASONS FOR CAUTION: These results may only apply to similar populations and to patients who do not require hospitalization due to SARS-CoV-2 infection. A limitation of the study is that only 1.8% of the study population had SARS-CoV-2 antibodies suggestive of previous infection. WIDER IMPLICATION OF THE FINDINGS: Maternal SARS-CoV-2 infection had no effect on the nuchal translucency thickness and there was no significantly increased risk of pregnancy loss for women with SARS-CoV-2 infection in first trimester pregnancy. Evidence concerning COVID-19 in pregnancy is still limited. These data indicate that infection with SARS-CoV-2 in not hospitalized women does not pose a significant threat in first trimester pregnancies. Follow-up studies are needed to establish any risk to a fetus exposed to maternal SARS-CoV-2 infection. STUDY FUNDING/COMPETING INTEREST(S): Prof. H.S.N. and colleagues received a grant from the Danish Ministry of Research and Education for research of COVID-19 among pregnant women. The Danish government was not involved in the study design, data collection, analysis, interpretation of data, writing of the report or decision to submit the paper for publication. A.I., J.O.-L., J.B.-R., D.M.S., J.E.-F. and E.R.H. received funding from a Novo Nordisk Foundation (NNF) Young Investigator Grant (NNF15OC0016662) and a Danish National Science Foundation Center Grant (6110-00344B). A.I. received a Novo Scholarship. J.O.-L. is funded by an NNF Pregraduate Fellowship (NNF19OC0058982). D.W. is funded by the NNF (NNF18SA0034956, NNF14CC0001, NNF17OC0027594). A.M.K. is funded by a grant from the Rigshospitalet's research fund. H.S.N. has received speaker's fees from Ferring Pharmaceuticals, Merck Denmark A/S and Ibsa Nordic (outside the submitted work). N.l.C.F. has received a grant from Gedeon Richter (outside the submitted work). A.M.K. has received speaker's fee from Merck (outside the submitted work). The other authors did not report any potential conflicts of interest. TRIAL REGISTRATION NUMBER: N/A.


Subject(s)
Abortion, Spontaneous/epidemiology , COVID-19/complications , Fetal Development , Nuchal Translucency Measurement/statistics & numerical data , Pregnancy Complications, Infectious/virology , Abortion, Spontaneous/virology , Adult , Antibodies, Viral/blood , COVID-19/blood , COVID-19/diagnosis , COVID-19/virology , COVID-19 Serological Testing/statistics & numerical data , Cohort Studies , Denmark/epidemiology , Female , Humans , Pregnancy , Pregnancy Complications, Infectious/blood , Pregnancy Complications, Infectious/diagnosis , Pregnancy Trimester, First , SARS-CoV-2/immunology , SARS-CoV-2/isolation & purification
4.
Infection ; 42(2): 433-6, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24272915

ABSTRACT

Acute focal bacterial nephritis (AFBN) is a rare, acute focal infection of the renal parenchyma without liquefaction. The pathogenesis is thought to be due to hematogenous infection or ascending infection from the lower urinary tract. Escherichia coli has been the major pathogen isolated in prior cases, but other Gram-negative enteric pathogens and Staphylococcus aureus have been reported as well. It is well described in children and adults with diabetes and organ transplantation, but has not been previously reported in healthy adults. We report a case of an immunocompetent adult female who presented with a methicillin-resistant Staphylococcus aureus bacteremia after a skin and soft tissue infection that resulted in AFBN.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Daptomycin/therapeutic use , Nephritis/drug therapy , Staphylococcal Infections/drug therapy , Acute Disease , Adult , Anti-Bacterial Agents/pharmacology , Daptomycin/pharmacology , Female , Humans , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Nephritis/microbiology , Nephritis/pathology , Skin Diseases, Bacterial/complications , Skin Diseases, Bacterial/drug therapy , Skin Diseases, Bacterial/pathology , Soft Tissue Infections/complications , Soft Tissue Infections/drug therapy , Soft Tissue Infections/pathology , Staphylococcal Infections/microbiology , Staphylococcal Infections/pathology , Treatment Outcome
5.
Sci Rep ; 14(1): 3804, 2024 02 15.
Article in English | MEDLINE | ID: mdl-38360908

ABSTRACT

Chronic wasting disease (CWD) is a highly contagious, fatal neurodegenerative disease caused by infectious prions (PrPCWD) affecting wild and captive cervids. Although experimental feeding studies have demonstrated prions in feces of crows (Corvus brachyrhynchos), coyotes (Canis latrans), and cougars (Puma concolor), the role of scavengers and predators in CWD epidemiology remains poorly understood. Here we applied the real-time quaking-induced conversion (RT-QuIC) assay to detect PrPCWD in feces from cervid consumers, to advance surveillance approaches, which could be used to improve disease research and adaptive management of CWD. We assessed recovery and detection of PrPCWD by experimental spiking of PrPCWD into carnivore feces from 9 species sourced from CWD-free populations or captive facilities. We then applied this technique to detect PrPCWD from feces of predators and scavengers in free-ranging populations. Our results demonstrate that spiked PrPCWD is detectable from feces of free-ranging mammalian and avian carnivores using RT-QuIC. Results show that PrPCWD acquired in natural settings is detectable in feces from free-ranging carnivores, and that PrPCWD rates of detection in carnivore feces reflect relative prevalence estimates observed in the corresponding cervid populations. This study adapts an important diagnostic tool for CWD, allowing investigation of the epidemiology of CWD at the community-level.


Subject(s)
Coyotes , Deer , Neurodegenerative Diseases , Prions , Wasting Disease, Chronic , Animals , Feces , Wasting Disease, Chronic/diagnosis , Wasting Disease, Chronic/epidemiology
7.
Nat Genet ; 19(3): 289-91, 1998 Jul.
Article in English | MEDLINE | ID: mdl-9662407

ABSTRACT

The somatosensory (SI) cortex of mice displays a patterned, nonuniform distribution of neurons in layer IV called the 'barrelfield' (ref. 1). Thalamocortical afferents (TCAs) that terminate in layer IV are segregated such that each barrel, a readily visible cylindrical array of neurons surrounding a cell-sparse center, represents a distinct receptive field. TCA arbors are confined to the barrel hollow and synapse on barrel-wall neurons whose dendrites are oriented toward the center of the barrel. Mice homozygous for the barrelless (brl) mutation, which occurred spontaneously in ICR stock at Université de Lausanne (Switzerland), fail to develop this patterned distribution of neurons, but still display normal topological organization of the SI cortex. Despite the absence of barrels and the overlapping zones of TCA arborization, the size of individual whisker representations, as judged by 2-deoxyglucose uptake, is similar to that of wild-type mice. We identified adenylyl cyclase type I (Adcy1) as the gene disrupted in brl mutant mice by fine mapping of proximal chromosome 11, enzyme assay, mutation analysis and examination of mice homozygous for a targeted disruption of Adcy1. These results provide the first evidence for involvement of cAMP signalling pathways in pattern formation of the brain.


Subject(s)
Adenylyl Cyclases/physiology , Membrane Proteins/physiology , Somatosensory Cortex/physiopathology , Adenylyl Cyclases/genetics , Animals , Base Sequence , Body Patterning/genetics , Brain/enzymology , Brain/physiopathology , DNA, Complementary , Female , Male , Membrane Proteins/genetics , Mice , Mice, Inbred C57BL , Mice, Knockout , Molecular Sequence Data , Neurons
8.
Sci Rep ; 13(1): 7838, 2023 05 15.
Article in English | MEDLINE | ID: mdl-37188858

ABSTRACT

Chronic wasting disease (CWD) is a fatal neurodegenerative disease caused by infectious prions (PrPCWD) affecting cervids. Circulating PrPCWD in blood may pose a risk for indirect transmission by way of hematophagous ectoparasites acting as mechanical vectors. Cervids can carry high tick infestations and exhibit allogrooming, a common tick defense strategy between conspecifics. Ingestion of ticks during allogrooming may expose naïve animals to CWD, if ticks harbor PrPCWD. This study investigates whether ticks can harbor transmission-relevant quantities of PrPCWD by combining experimental tick feeding trials and evaluation of ticks from free-ranging white-tailed deer (Odocoileus virginianus). Using the real-time quaking-induced conversion (RT-QuIC) assay, we show that black-legged ticks (Ixodes scapularis) fed PrPCWD-spiked blood using artificial membranes ingest and excrete PrPCWD. Combining results of RT-QuIC and protein misfolding cyclic amplification, we detected seeding activity from 6 of 15 (40%) pooled tick samples collected from wild CWD-infected white-tailed deer. Seeding activities in ticks were analogous to 10-1000 ng of CWD-positive retropharyngeal lymph node collected from deer upon which they were feeding. Estimates revealed a median infectious dose range of 0.3-42.4 per tick, suggesting that ticks can take up transmission-relevant amounts of PrPCWD and may pose a CWD risk to cervids.


Subject(s)
Deer , Ixodes , Neurodegenerative Diseases , Prions , Wasting Disease, Chronic , Animals , Prions/metabolism , Deer/metabolism , Wasting Disease, Chronic/metabolism , Ixodes/metabolism
9.
Curr Opin Cell Biol ; 5(2): 269-73, 1993 Apr.
Article in English | MEDLINE | ID: mdl-8507499

ABSTRACT

Clones for six mammalian adenylyl cyclases have recently been isolated. One of these enzymes, the type I calmodulin-sensitive adenylyl cyclase, is neurospecific and is implicated in neuroplasticity. We propose that the type I adenylyl cyclase may be important for learning and memory because it allows Ca(2+)-amplified cAMP signals, synergism between Ca2+ and cAMP-activated kinases, and positive feedback regulation of Ca2+ channels by cAMP-dependent protein kinase.


Subject(s)
Adenylyl Cyclases/physiology , Neuronal Plasticity/physiology , Adenylyl Cyclases/chemistry , Animals , Calcium , Calmodulin , Genetic Variation , Isoenzymes , Models, Biological
10.
Phys Rev Lett ; 105(15): 152501, 2010 Oct 08.
Article in English | MEDLINE | ID: mdl-21230896

ABSTRACT

The radionuclide 22Na is a potential astronomical observable that is expected to be produced in classical novae in quantities that depend on the thermonuclear rate of the 22Na(p,γ)23Mg reaction. We have measured the strengths of low-energy 22Na(p,γ)23Mg resonances directly and absolutely using a radioactive 22Na target. We find the strengths of resonances at Ep=213, 288, 454, and 610 keV to be higher than previous measurements by factors of 2.4-3.2, and we exclude important contributions to the rate from proposed resonances at Ep=198, 209, and 232 keV. The 22Na abundances expected in the ejecta of classical novae are reduced by a factor of ≈2.

11.
J Cell Biol ; 130(3): 701-10, 1995 Aug.
Article in English | MEDLINE | ID: mdl-7622569

ABSTRACT

MAP kinase activity is necessary for growth factor induction of neurite outgrowth in PC12 cells. Although NGF and EGF both stimulate MAP kinase activity, EGF does not stimulate neurite extension. We report that EGF, in combination with KCl, stimulates neurite outgrowth in PC12 cells. This phenomenon was independent of intracellular Ca2+ increases and not due to enhancement of MAP kinase activity over that seen with EGF alone. However, EGF plus KCl increased intracellular cAMP, and other cAMP elevating agents acted synergistically with EGF to promote neurite outgrowth. Stimulation of neurite outgrowth by cAMP and EGF was blocked by inhibitors of transcription suggesting that synergistic regulation of transcription by the cAMP and MAP kinase pathways may stimulate neurite growth.


Subject(s)
Epidermal Growth Factor/pharmacology , Neurites/physiology , Potassium Chloride/pharmacology , Signal Transduction , Animals , Calcium/metabolism , Calcium-Calmodulin-Dependent Protein Kinases/metabolism , Cell Differentiation , Cyclic AMP/metabolism , Drug Synergism , Mitogen-Activated Protein Kinase Kinases , Nerve Growth Factors/pharmacology , PC12 Cells/drug effects , Protein Biosynthesis , Protein Kinases/genetics , Protein Kinases/metabolism , Rats , Transcription, Genetic
12.
J Cell Biol ; 111(4): 1559-69, 1990 Oct.
Article in English | MEDLINE | ID: mdl-2170423

ABSTRACT

Neuromodulin (also called GAP43, G50, F1, pp46), a neural-specific calmodulin binding protein, is a major protein kinase C substrate found in developing and regenerating neurons. Here, we report the immunocytochemical characterization of neuromodulin in cultured 0-2A bipotential glial precursor cells obtained from newborn rat brain. Neuromodulin is also present in oligodendrocytes and type 2 astrocytes (stellate-shaped astrocytes), which are both derived from the bipotential glial 0-2A progenitor cells, but is absent of type 1 astrocytes (flat protoplasmic astrocytes). These results support the hypothesis of a common cell lineage for neurons and bipotential 0-2A progenitor cells and suggest that neuromodulin plays a more general role in plasticity during development of the central nervous system. The expression of neuromodulin in secondary cultures of newborn rat oligodendrocytes and its absence in type 1 astrocytes was confirmed by Northern blot analysis of isolated total RNA from these different types of cells using a cDNA probe for the neuromodulin mRNA and by Western blot analysis of the cell extracts using polyclonal antibodies against neuromodulin. The properties of the neuromodulin protein in cultured oligodendrocytes and neuronal cells have been compared. Although neuromodulin in oligodendrocytes is soluble in 2.5% perchloric acid like the neuronal counterpart it migrates essentially as a single protein spot on two-dimensional gel electrophoresis whereas the neuronal antigen can be resolved into at least three distinct protein spots. To obtain precise alignments of the different neuromodulin spots from these two cell types, oligodendrocyte and neuronal cell extracts were mixed together and run on the same two-dimensional gel electrophoresis system. Oligodendroglial neuromodulin migrates with a pI identical to the basic forms of the neuronal protein in isoelectric focusing gel. However, the glial neuromodulin shows a slightly lower mobility in the second dimensional lithium dodecyl sulfate-PAGE than its neuronal counterpart. As measured by 32Pi incorporation, neuromodulin phosphorylation in oligodendrocytes is dramatically increased after short-term phorbol ester treatments, which activate protein kinase C, and is totally inhibited by long-term phorbol ester treatments, which downregulates protein kinase C, thus confirming its probable specific in vivo phosphorylation by protein kinase C. In primary cultures of neuronal cells, two of the three neuromodulin spots were observed to be phosphorylated with an apparent preferential phosphorylation of the more acid forms.


Subject(s)
Calmodulin-Binding Proteins/physiology , Membrane Glycoproteins/physiology , Nerve Tissue Proteins/physiology , Oligodendroglia/physiology , Animals , Animals, Newborn , Astrocytes/physiology , Brain/cytology , Calmodulin-Binding Proteins/analysis , Electrophoresis, Gel, Two-Dimensional , GAP-43 Protein , Immunohistochemistry , In Vitro Techniques , Membrane Glycoproteins/analysis , Nerve Tissue Proteins/analysis , Neurons/chemistry , Oligodendroglia/chemistry , Optic Nerve/cytology , Perchlorates , Phenotype , Protein Kinase C/metabolism , RNA, Messenger/metabolism , Rats , Substrate Specificity
13.
J Pediatr Urol ; 15(5): 528.e1-528.e8, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31445857

ABSTRACT

INTRODUCTION: Pediatric bladder and bowel dysfunction (BBD) is a common problem in children. However, the current ability to diagnosis and quantify pediatric BBD is limited as only a few validated instruments exist. In addition, the current questionnaires are limited by their lack of psychometric processing and methods of validation. To address these issues, the authors developed a new questionnaire to objectively diagnose pediatric BBD symptoms. This study aimed to evaluate the performance of this newly devised objective instrument in diagnosing and quantifying the symptomatology of BBD in children. MATERIALS AND METHODS: An 18-item, 5-point questionnaire was developed using both a literature review and expert opinions. The total questionnaire score could range from 0 to 72. Questions were subgrouped into six symptom categories: (1) nocturnal enuresis, (2) lower urinary tract symptoms, (3) urinary holding, (4) infrequent urination, (5) bowel symptoms, and (6) daytime urinary incontinence. The questionnaire also assessed the degree of bother associated with the symptoms. Patients were divided into cases and controls, and these two groups were compared. DISCUSSION/RESULTS: A total of 1265 new patients (758 cases and 507 controls) completed the new BBD questionnaire. The mean age of the whole study cohort was 9.5 years (range, 3-19 years). The total mean questionnaire score was significantly higher at 23 (3-58) in the cases, compared with 8 (0-35) in the controls (p < 0.001) (Summary Figure). Reliability analysis of the 18-item instrument showed a Cronbach's alpha reliability coefficient of 0.80 for the scale. CONCLUSIONS: This new instrument provides a valid and reliable method for diagnosis of pediatric BBD and classification of patients into subcategories of BBD based on their specific symptoms.


Subject(s)
Constipation/diagnosis , Enuresis/diagnosis , Mass Screening/methods , Psychometrics/methods , Surveys and Questionnaires , Urinary Incontinence/diagnosis , Adolescent , Child , Child, Preschool , Constipation/epidemiology , Enuresis/epidemiology , Female , Follow-Up Studies , Humans , Male , Morbidity/trends , Reproducibility of Results , Retrospective Studies , United States/epidemiology , Urinary Incontinence/epidemiology , Young Adult
14.
Neuron ; 6(3): 411-20, 1991 Mar.
Article in English | MEDLINE | ID: mdl-1825782

ABSTRACT

Neuromodulin (GAP-43) is a membrane protein that is transported to neuronal growth cones. Zuber and co-workers have proposed that the N-terminal 10 amino acid sequence of neuromodulin is sufficient to target proteins to growth cones. We demonstrate that a neuromodulin-beta-galactosidase fusion protein is transported to growth cones of cultured rat neurons, whereas a fusion protein containing the N-terminal 10 amino acids of neuromodulin and beta-galactosidase is not. A mutant neuromodulin lacking cysteines 3 and 4, the palmitylation sites required for membrane attachment, does not target beta-galactosidase to growth cones. We conclude that membrane attachment is required for growth cone accumulation and that structural elements, in addition to the first 10 amino acids of neuromodulin, may be required for growth cone targeting.


Subject(s)
Embryo, Mammalian/innervation , Membrane Glycoproteins/metabolism , Nerve Tissue Proteins/metabolism , Neurons/metabolism , Animals , Base Sequence , Blotting, Western , Cell Membrane/metabolism , Cells, Cultured , Fluorescent Antibody Technique , GAP-43 Protein , Membrane Glycoproteins/genetics , Mesencephalon/cytology , Mesencephalon/metabolism , Molecular Sequence Data , Nerve Tissue Proteins/genetics , Neurons/cytology , Oligonucleotides/genetics , Rats , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Transfection , beta-Galactosidase/genetics , beta-Galactosidase/metabolism
15.
Neuron ; 22(1): 63-72, 1999 Jan.
Article in English | MEDLINE | ID: mdl-10027290

ABSTRACT

Neuronal activity-dependent processes are believed to mediate the formation of synaptic connections during neocortical development, but the underlying intracellular mechanisms are not known. In the visual system, altering the pattern of visually driven neuronal activity by monocular deprivation induces cortical synaptic rearrangement during a postnatal developmental window, the critical period. Here, using transgenic mice carrying a CRE-lacZ reporter, we demonstrate that a calcium- and cAMP-regulated signaling pathway is activated following monocular deprivation. We find that monocular deprivation leads to an induction of CRE-mediated lacZ expression in the visual cortex preceding the onset of physiologic plasticity, and this induction is dramatically downregulated following the end of the critical period. These results suggest that CRE-dependent coordinate regulation of a network of genes may control physiologic plasticity during postnatal neocortical development.


Subject(s)
Aging/physiology , Calcium/metabolism , Cyclic AMP Response Element-Binding Protein/genetics , Cyclic AMP/metabolism , Neuronal Plasticity/physiology , Transcription, Genetic , Visual Cortex/physiology , Animals , Geniculate Bodies/physiology , Mice , Mice, Transgenic , Sensory Deprivation/physiology , Transcription, Genetic/physiology , Vision, Monocular/physiology
16.
Neuron ; 20(6): 1199-210, 1998 Jun.
Article in English | MEDLINE | ID: mdl-9655507

ABSTRACT

Activation of adenylyl cyclase and the consequent production of cAMP is a process that has been shown to be central to invertebrate model systems of information storage. In the vertebrate brain, it has been suggested that a presynaptic cascade involving Ca influx, cAMP production, and subsequent activation of cAMP-dependent protein kinase is necessary for induction of long-term potentiation (LTP) at the cerebellar parallel fiber-Purkinje cell synapse. We have used mutant mice in which the major Ca-sensitive adenylyl cyclase isoform of cerebellar cortex (type I) is deleted to show that this results in an approximately 65% reduction in cerebellar Ca-sensitive cyclase activity and a nearly complete blockade of cerebellar LTP assessed using granule cell-Purkinje cell pairs in culture. This blockade is not accompanied by alterations in a number of basal electrophysiological parameters and may be bypassed by application of an exogenous cAMP analog, suggesting that it results specifically from deletion of the type I adenylyl cyclase.


Subject(s)
Adenylyl Cyclases/genetics , Long-Term Potentiation/physiology , Purkinje Cells/enzymology , Adenylyl Cyclases/metabolism , Animals , Cell Membrane/enzymology , Cells, Cultured , Cyclic AMP/analogs & derivatives , Cyclic AMP/metabolism , Cyclic AMP/pharmacology , Electrophysiology , Enzyme Inhibitors/pharmacology , Excitatory Postsynaptic Potentials/drug effects , Excitatory Postsynaptic Potentials/physiology , Gait/physiology , Glutamic Acid/pharmacology , Mice , Mice, Inbred C57BL , Mice, Knockout , Mutation/physiology , Nerve Fibers/enzymology , Psychomotor Performance/physiology , Purkinje Cells/cytology , Purkinje Cells/ultrastructure , Thionucleotides/pharmacology
17.
Neuron ; 16(5): 973-82, 1996 May.
Article in English | MEDLINE | ID: mdl-8630255

ABSTRACT

Gene expression regulated by the cAMP response element (CRE) has been implicated in synaptic plasticity and long-term memory. It has been proposed that CRE-mediated gene expression is stimulated by signals that induce long-term potentiation (LTP). To test this hypothesis, we made mice transgenic for a CRE-regulated reporter construct. We focused on long-lasting long-term potentiation (L-LTP), because it depends on cAMP-dependent protein kinase activity (PKA) and de novo gene expression. CRE-mediated gene expression was markedly increased after L-LTP, but not after decremental UP (D-LTP). Furthermore, inhibitors of PKA blocked L-LTP and associated increases in CRE-mediated gene expression. These data demonstrate that the signaling required for the generation of L-LTP but not D-LTP is sufficient to stimulate CRE-mediated transcription in the hippocampus.


Subject(s)
Hippocampus/physiology , Long-Term Potentiation , Animals , Calcium Channels/physiology , Cyclic AMP/physiology , Cyclic AMP Response Element-Binding Protein/physiology , Gene Expression Regulation , Mice , Mice, Inbred C57BL , Phosphorylation , Promoter Regions, Genetic , Protein Kinases/physiology , Receptors, Cyclic AMP/metabolism , Receptors, N-Methyl-D-Aspartate/physiology , Signal Transduction
18.
Neuron ; 19(2): 381-9, 1997 Aug.
Article in English | MEDLINE | ID: mdl-9292727

ABSTRACT

The role of cGMP in olfactory signaling is not fully understood, but it is believed to play a modulatory role in intracellular signaling in vertebrate olfactory receptor neurons (ORNs). Here, we present evidence that cGMP in ORNs may play an important role in recognition of biologically relevant odors and olfactory learning. Specifically, we investigated the cellular mechanisms underlying olfactory imprinting in salmon. Salmon learn odors associated with their natal site as juveniles and later use these odors to guide their homing migration. This imprinting is believed to involve sensitization of the peripheral olfactory system to specific homestream odorants. We imprinted juvenile salmon to the odorant beta-phenylethyl alcohol (PEA) and examined the sensitivity of olfactory adenylyl and guanylyl cyclases to PEA during development. Stimulation of guanylyl cyclase activity by PEA was significantly greater in olfactory cilia isolated from PEA-imprinted salmon compared with PEA-naive fish only at the time of the homing migration, 2 years after PEA exposure. These results suggest that sensitization of olfactory guanylyl cyclase may play an important role in olfactory imprinting by salmon.


Subject(s)
Guanylate Cyclase/physiology , Imprinting, Psychological/physiology , Odorants , Olfactory Pathways/enzymology , Animals , Oncorhynchus kisutch , Sensitivity and Specificity
19.
Neuron ; 6(3): 431-43, 1991 Mar.
Article in English | MEDLINE | ID: mdl-2001286

ABSTRACT

The Drosophila learning mutant, rutabaga, is deficient in the calmodulin-sensitive adenylate cyclase, and studies of associative learning in Aplysia have implicated this enzyme in neuroplasticity. Therefore, the distribution of mRNA encoding the calmodulin-sensitive adenylate cyclase in rat brain was examined by in situ hybridization. mRNA for this enzyme is expressed in specific areas of brain that have been implicated in learning and memory, including the neocortex, the hippocampus, and the olfactory system. The presence of mRNA for this enzyme in the pyramidal and granule cells of the hippocampal formation provides evidence that it is found in neurons. These data are consistent with the proposal that the calmodulin-sensitive adenylate cyclase plays an important role in learning and memory.


Subject(s)
Adenylyl Cyclases/genetics , Brain/enzymology , Calmodulin/pharmacology , Learning/physiology , Memory/physiology , RNA, Messenger/metabolism , Adenylyl Cyclases/metabolism , Adenylyl Cyclases/physiology , Animals , Base Sequence , Brain/cytology , Brain/physiology , Cerebral Cortex/cytology , Cerebral Cortex/metabolism , Cerebral Cortex/physiology , DNA/genetics , DNA Probes , Hippocampus/cytology , Hippocampus/metabolism , Hippocampus/physiology , Male , Molecular Sequence Data , Nucleic Acid Hybridization , Olfactory Pathways/cytology , Olfactory Pathways/metabolism , Olfactory Pathways/physiology , Oligonucleotides , RNA, Messenger/genetics , Rats , Rats, Inbred Strains
20.
Neuron ; 21(3): 495-504, 1998 Sep.
Article in English | MEDLINE | ID: mdl-9768837

ABSTRACT

Acute desensitization of olfactory signaling is a critical property of the olfactory system that allows animals to detect and respond to odorants. Correspondingly, an important feature of odorant-stimulated cAMP increases is their transient nature, a phenomenon that may be attributable to the unique regulatory properties of the olfactory adenylyl cyclase (AC3). AC3 is stimulated by receptor activation and inhibited by Ca2+ through Ca2+/calmodulin kinase II (CaMKII) phosphorylation at Ser-1076. Since odorant-stimulated cAMP increases are accompanied by elevated intracellular Ca2+, CaMKII inhibition of AC3 may contribute to termination of olfactory signaling. To test this hypothesis, we generated a polyclonal antibody specific for AC3 phosphorylated at Ser-1076. A brief exposure of mouse olfactory cilia or primary olfactory neurons to odorants stimulated phosphorylation of AC3 at Ser-1076. This phosphorylation was blocked by inhibitors of CaMKII, which also ablated cAMP decreases associated with odorant-stimulated cAMP transients. These data define a novel mechanism for termination of olfactory signaling that may be important in olfactory responses.


Subject(s)
Adenylyl Cyclases/metabolism , Calcium-Calmodulin-Dependent Protein Kinases/metabolism , Neurons/physiology , Odorants , Olfactory Mucosa/physiology , Signal Transduction , Adenylyl Cyclase Inhibitors , Adenylyl Cyclases/chemistry , Animals , Animals, Newborn , Calcium-Calmodulin-Dependent Protein Kinase Type 2 , Cells, Cultured , Cilia/drug effects , Cilia/physiology , Cyclic AMP/metabolism , Enzyme Inhibitors/pharmacology , Male , Mice , Mice, Inbred C57BL , Models, Biological , Neurons/drug effects , Neurons/enzymology , Olfactory Mucosa/drug effects , Peptide Fragments/chemistry , Peptide Fragments/metabolism , Phosphorylation , Serine
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