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2.
J Appl Microbiol ; 120(6): 1711-22, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27005691

ABSTRACT

AIM: To elucidate the distribution and circulation dynamics of Campylobacter and Salmonella in Japanese chicken broiler flocks. METHODS AND RESULTS: A 2-year investigation of the distribution of Campylobacter and Salmonella was conducted in 25 broiler flocks at nine farms in Japan from 2013 to 2014. Campylobacter and Salmonella tested positive in 11 (44·0%) and 24 (96·0%) broiler flocks respectively. One hundred and ninety-five Campylobacter and 184 Salmonella isolates were characterized into 12 Campylobacter (including two novel genotypes) and three Salmonella MLST genotypes. Only Salmonella isolation between caecal and environmental samples were significantly correlated. Further, one litter sample tested positive for Salmonella before new chicks were introduced. The Campylobacter strains rapidly lost culturability within 2-18 days; in contrast, the Salmonella strains survived from 64-211 days in artificially inoculated water samples. CONCLUSION: No persistent circulation-mediated Campylobacter contamination was observed. In contrast, circulation of Salmonella in broiler houses was seen, apparently due to the litter excreted from broiler flocks, as well as Salmonella-contaminated water and feed. SIGNIFICANCE AND IMPACT OF THE STUDY: This paper provides the distribution, genotypic data and circulation dynamics of Campylobacter and Salmonella as recently observed in Japanese chicken broiler farms.


Subject(s)
Campylobacter Infections/veterinary , Campylobacter/isolation & purification , Poultry Diseases/microbiology , Salmonella Infections, Animal/microbiology , Salmonella/isolation & purification , Animals , Campylobacter/classification , Campylobacter/genetics , Campylobacter Infections/microbiology , Cecum/microbiology , Chickens , Farms , Japan , Multilocus Sequence Typing , Prevalence , Salmonella/classification , Salmonella/genetics
3.
J Clin Pharm Ther ; 41(3): 273-8, 2016 Jun.
Article in English | MEDLINE | ID: mdl-26990125

ABSTRACT

WHAT IS KNOWN AND OBJECTIVE: Polypharmacy is a risk factor for fall-related fractures. However, it is unclear whether polypharmacy itself is a direct risk factor. The aim of this study was to assess the association between the risk of fall-related fractures and polypharmacy of driving-prohibited and driving-cautioned medications in older outpatients. METHODS: We conducted a cross-sectional study of outpatients aged ≥65 years receiving any medication, using two sampling data sets from the October 2011 and October 2012 national insurance claims in Japan. Using logistic regression models, we analysed the association between the numbers of driving-prohibited or driving-cautioned medications administered or dispensed to patients and the occurrence of fall-related fractures. RESULTS AND DISCUSSION: In both analysis populations (n = 303 311 and n = 326 219), the adjusted odds ratio of driving-prohibited medications for the occurrence of fall-related fractures significantly increased as the number of these medications per patient increased (95% confidence interval: 0, 1-2, 3-4, 5-6, 7-8 and ≥9 medications; reference, 0·95-1·24, 1·18-1·79, 1·47-2·96, 1·26-5·21 and 1·50-15·2 in October 2011 and reference, 1·11-1·42, 1·39-2·03, 1·33-2·72, 1·53-5·49 and 1·30-13·0 in October 2012). The association was maintained even for sensitivity analyses restricted to medications administered orally or orally and by injection. However, a similar association was not observed for driving-cautioned medications. WHAT IS NEW AND CONCLUSION: Medication class is a more important risk factor for fall-related fractures rather than polypharmacy alone with no regard to medication class.


Subject(s)
Accidental Falls/statistics & numerical data , Drug-Related Side Effects and Adverse Reactions/epidemiology , Fractures, Bone/epidemiology , Polypharmacy , Aged , Aged, 80 and over , Automobile Driving , Cross-Sectional Studies , Female , Fractures, Bone/etiology , Humans , Japan/epidemiology , Logistic Models , Male , Outpatients , Risk Factors
4.
Vet Rec ; 177(8): 202, 2015 Aug 22.
Article in English | MEDLINE | ID: mdl-26286947

ABSTRACT

A coprological survey with detailed clinical observation of naturally occurring haemorrhagic enteritis (HE) cases was conducted to understand the pathophysiology of HE by clarifying the infection status of Eimeria and enteropathogenic bacteria in cattle. Faecal samples from 55 cases of HE and 26 clinically normal animals were collected, and a quantitative examination of Eimeria and potential enteropathogenic bacteria was performed. The number of Eimeria species oocysts per gram of faeces (OPG) exceeded 10,000 in 69.1 per cent of HE cases with a maximum of 1,452,500 OPG and Eimeria zuernii was found to be overwhelmingly dominant. A significant increase in faecal coliform count was observed in HE cases compared with clinically normal animals. Among the animals shedding >10,000 OPG, 42.9 per cent showed a remarkable increase in Clostridium perfringens abundance (>104 CFU/g) in the faeces. In the cases with C. perfringens detected, its abundance was positively correlated with Eimeria OPG and high C. perfringens abundance was always accompanied by high Eimeria OPG. E. zuernii is likely to play a crucial role in massive multiplication of C. perfringens in HE in cattle.

5.
J Clin Pharm Ther ; 39(1): 45-52, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24106917

ABSTRACT

WHAT IS KNOWN AND OBJECTIVE: Patients' poor adherence to medications is reported to be related to the individual patients' beliefs and cognitions and their trust of the medical staff. However, the causes of the two forms of non-adherence, intentional and unintentional behaviours, have yet to be clarified. This study compared psychological latent factors associated with intentional and unintentional non-adherence to chronic medication regimens, focusing on the potential effects of (i) patients' dissatisfaction with treatment and their relationships with the medical staff and (ii) patients' subliminal rational thinking processes, which weighed the positive values such as their expectations of benefits from treatment against negative values such as their dissatisfaction. METHODS: Two cross-sectional surveys were undertaken of patients given medications for chronic diseases, using a questionnaire developed and validated in this study. One survey was undertaken in three hospitals and the other survey, online throughout Japan. We scored the individual latent factors using the questionnaire and calculated the differential score between two negatively correlated latent factors to quantify patients' subliminal rational thinking process. We compared the adjusted odds ratio (OR) of latent factors between intentional and unintentional non-adherence to medication in both surveys. RESULTS AND DISCUSSION: Of the eligible subjects, 149 hospitalized patients and 524 survey participants completed the questionnaire. Intentional non-adherence was associated with patient dissatisfaction with treatment including interpersonal relationships with medical staff in both hospitalized patients and online survey participants (95% confidence interval of adjusted OR for Dissatisfaction, 1·20-16·26 in the hospital-based survey and 1·33-3·45 in the online survey). In both surveys, intentional non-adherence was significantly associated with the differential score between two negatively correlated latent factors, Willingness and Dissatisfaction (P = 0·02 in the hospital-based survey and P < 0·001 in the online survey). However, these associations were not evident in unintentionally non-adherent patients. WHAT IS NEW AND CONCLUSIONS: Patients' dissatisfaction and their resulting rational judgments are unique, consistent determinants of intentional non-adherence to medications, but not of unintentional non-adherence.


Subject(s)
Judgment , Medication Adherence , Patient Satisfaction , Adult , Aged , Chronic Disease/drug therapy , Cross-Sectional Studies , Female , Humans , Japan , Male , Middle Aged , Professional-Patient Relations , Surveys and Questionnaires
6.
Free Radic Res ; 47(9): 731-9, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23789828

ABSTRACT

Oxidative stress is considered to be related to the onset and/or progression of Alzheimer's disease (AD), but there is insufficient evidence of its role(s). In this study, we evaluated the relationships between the brain redox state and cognitive function using a triple transgenic mouse model of AD (3 × Tg-AD mouse). One group of 3 × Tg-AD mice started to receive an α-tocopherol-supplemented diet at 2 months of age and another group of 3 × Tg-AD mice was fed a normal diet. The levels of α-tocopherol, reduced glutathione, oxidized glutathione, and lipid peroxidation were decreased in the cerebral cortex and hippocampus at 4 months of age in the 3 × Tg-AD mice fed a normal diet. These reductions were abrogated by the supplementation of α-tocopherol in the diet. During Morris water maze testing, the 3 × Tg-AD mice did not exhibit cognitive impairment at 4 months of age, but started to show cognitive dysfunction at 6 months of age, and α-tocopherol supplementation suppressed this dysfunction. Magnetic resonance imaging (MRI) using 3-hydroxymethyl-proxyl as a probe showed decreases in the signal intensity in the brains of 3 × Tg-AD mice at 4 months of age, and this reduction was clearly attenuated by α-tocopherol supplementation. Taken together, these findings suggest that oxidative stress can be associated with the cognitive impairment in 3 × Tg-AD mice. Furthermore, MRI might be a powerful tool to noninvasively evaluate the increases in reactive radicals, especially those occurring during the early stages of AD.


Subject(s)
Alzheimer Disease/pathology , Brain/diagnostic imaging , Cognitive Dysfunction/diagnostic imaging , Magnetic Resonance Imaging , Oxidative Stress , Alzheimer Disease/diagnosis , Alzheimer Disease/diagnostic imaging , Alzheimer Disease/genetics , Animals , Brain/metabolism , Brain/pathology , Cerebral Cortex/diagnostic imaging , Cerebral Cortex/pathology , Cognitive Dysfunction/diagnosis , Cognitive Dysfunction/pathology , Disease Models, Animal , Humans , Lipid Peroxidation , Mice , Mice, Transgenic , Radiography
7.
Clin Exp Rheumatol ; 30(1): 85-92, 2012.
Article in English | MEDLINE | ID: mdl-22325923

ABSTRACT

OBJECTIVES: We simultaneously assessed ultrasonography (US) and magnetic resonance imaging (MRI) in comparison with histopathological changes in the knee joints of long-lasting arthritis patients. METHODS: We studied 15 patients with rheumatoid arthritis and 5 patients with osteoarthritis, who underwent total knee arthroplasty. On the day before surgery, the joints were examined by US and contrast-enhanced MRI. In US, synovitis was graded with 0-3 grey scale (GSUS) and power Doppler (PDUS). In MRI, synovitis was graded according to OMERACT-RAMRIS (grade 0-3). Synovial tissue samples were obtained during arthroplasty and evaluated on the basis of inflammatory cell infiltrates (grade 0-3), synovial lining layer thickness (grade 0-3) and vascularity (grade 0-3). RESULTS: Positive findings of PDUS and contrast-enhanced MRI were 45% and 85% of 20 operated joints, respectively. GSUS, PDUS and MRI synovitis were well correlated with overall histopathological grades of synovitis (Spearman correlation coefficients 0.48, 0.84 and 0.48, p<0.05, p<0.01 and p<0.05, respectively). Moreover, positive PDUS findings were closely associated with all pathological comportments of synovitis including inflammatory cell infiltrates, synovial lining layer thickness and vascularity. CONCLUSIONS: The present study revealed that positive PDUS findings more faithfully illustrated active synovitis than MRI, whereas contrast-enhanced MRI was more sensitive in detecting synovitis in patients with long-lasting arthritis. It is important to understand distinct features of the both modalities for clinical assessment of chronic joint diseases.


Subject(s)
Arthroplasty, Replacement, Knee , Knee Joint/surgery , Magnetic Resonance Imaging/methods , Synovitis/diagnosis , Ultrasonography, Doppler/methods , Adult , Aged , Aged, 80 and over , Arthritis, Rheumatoid/diagnostic imaging , Arthritis, Rheumatoid/pathology , Arthritis, Rheumatoid/surgery , Female , Humans , Knee Joint/diagnostic imaging , Knee Joint/pathology , Male , Middle Aged , Osteoarthritis/diagnostic imaging , Osteoarthritis/pathology , Osteoarthritis/surgery , Synovitis/diagnostic imaging , Synovitis/pathology , Synovitis/surgery
10.
Neuroscience ; 135(4): 1017-23, 2005.
Article in English | MEDLINE | ID: mdl-16165299

ABSTRACT

Classical eyeblink conditioning has been known to depend critically on the cerebellum. Apparently consistent with this, glutamate receptor subunit delta2 null mutant mice, which have serious morphological and functional deficiencies in the cerebellar cortex, are severely impaired in delay paradigm. However, these mutant mice successfully learn in trace paradigm, even in '0-trace paradigm,' in which the unconditioned stimulus starts just after the conditioned stimulus terminates. Our previous studies revealed that the hippocampus and the muscarinic acetylcholine receptors play crucial roles in 0-trace paradigm in glutamate receptor subunit delta2 null mutant mice unlike in wild-type mice, suggesting a large contribution of the forebrain to 0-trace conditioning in this type of mutant mice. In the present study, we investigated the role of N-methyl-D-aspartate receptors in 0-trace eyeblink conditioning in glutamate receptor subunit delta2 null mutant mice. Mice were injected intraperitoneally with the noncompetitive N-methyl-d-aspartate receptor antagonist (+)MK-801 (0.1mg/kg) or saline, and conditioned with 350-ms tone conditioned stimulus followed by 100-ms periorbital shock unconditioned stimulus. Glutamate receptor subunit delta2 null mutant mice that received (+)MK-801 injection exhibited a severe impairment in acquisition of the conditioned response, compared with the saline-injected glutamate receptor subunit delta2 null mutant mice. In contrast, wild-type mice were not impaired in acquisition of 0-trace conditioned response by (+)MK-801 injection. After the injection solution was changed from (+)MK-801 to saline, glutamate receptor subunit delta2 null mutant mice showed a rapid and partial recovery of performance of the conditioned response. On the other hand, when the injection solution was changed from saline to (+)MK-801, glutamate receptor subunit delta2 null mutant mice showed a marked impairment in expression of the pre-acquired conditioned response, whereas impairment of the expression was small in wild-type mice. Injection of (+)MK-801 had no significant effects on spontaneous eyeblink frequency or startle eyeblink frequency to the tone conditioned stimulus in either glutamate receptor subunit delta2 null mutant mice or wild-type mice. These results suggest that N-methyl-D-aspartate receptors play critical roles both in acquisition and expression of the conditioned response in 0-trace eyeblink conditioning in glutamate receptor subunit delta2 null mutant mice.


Subject(s)
Blinking/physiology , Brain/physiology , Conditioning, Eyelid/physiology , Receptors, Glutamate/deficiency , Receptors, N-Methyl-D-Aspartate/metabolism , Animals , Brain/drug effects , Conditioning, Eyelid/drug effects , Dizocilpine Maleate/pharmacology , Excitatory Amino Acid Antagonists/pharmacology , Mice , Mice, Mutant Strains , Receptors, Glutamate/genetics , Receptors, N-Methyl-D-Aspartate/drug effects
11.
Clin Exp Immunol ; 138(2): 237-44, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15498032

ABSTRACT

There is accumulating evidence that haem oxygenase (HO)-1 plays a protective role in various disorders. The beneficial efficacy of HO-1 induction therapy has been shown in renal diseases such as glomerulonephritis, interstitial nephritis and drug induced nephrotoxicity. However, involvement of HO-1 in the development of autoimmune renal diseases remains uncertain. To assess the clinical efficacy of HO-1 induction therapy for lupus glomerulonephritis, MRL/lpr mice were intraperitoneally injected with 100 micromol/kg hemin, a potent HO-1 inducer, or PBS as controls, once a week from 6 weeks of age to 21-24 weeks-old. We found that treatment with hemin led to a significant reduction of proteinuria and remarkable amelioration of glomerular lesions accompanied by decreased immune depositions. In addition, the circulating IgG anti-double-stranded DNA antibody level was significantly decreased in hemin treated mice when compared with controls. A single intraperitoneal injection with hemin resulted in reduction of inducible nitric oxide synthase expression in the kidney and spleen, and serum interferon-gamma level. Our results suggest that HO-1 induction therapy ameliorates lupus nephritis by suppressing nitric oxide (NO) dependent inflammatory responses and attenuating production of pathogenic autoantibodies.


Subject(s)
Antibodies, Antinuclear/biosynthesis , DNA/immunology , Heme Oxygenase (Decyclizing)/immunology , Lupus Nephritis/immunology , Nitric Oxide Synthase/analysis , Animals , Cells, Cultured , Cytokines/analysis , Female , Heme Oxygenase-1 , Hemin/administration & dosage , Hemin/immunology , Immunoglobulin G/immunology , Injections, Intraperitoneal , Kidney/immunology , Kidney Glomerulus/immunology , Membrane Proteins , Mice , Mice, Inbred MRL lpr , Nitric Oxide Synthase Type II , Spleen/immunology
12.
J Med Genet ; 41(5): 342-9, 2004 May.
Article in English | MEDLINE | ID: mdl-15121771

ABSTRACT

INTRODUCTION: We present a family comprising a clinically normal mother and two daughters, each with severe encephalopathy with onset in late childhood. A third daughter had died previously of an earlier onset but neuropathologically similar disease. METHODS: Sequence analysis of the entire mtDNA was carried out in muscle, fibroblasts, and lymphocytes of the affected daughters and unaffected mother. Biochemical analysis of individual respiratory chain enzymes was performed on the same tissues, and on several transmitochondrial cybrid clones containing the nucleus of a 143B.206 osteosarcoma cell line and the mutant mtDNA. RESULTS: Genetic analyses revealed in both daughters and mother the presence of a novel mutation in the tRNA(Ile) gene of mtDNA, which was homoplasmic in fibroblasts, lymphocytes, and skeletal muscle of the two patients. It was also homoplasmic in fibroblast and skeletal muscle samples of the mother, and approximately 97% heteroplasmic in her lymphocytes. Combined defects of complexes I and IV of the mitochondrial respiratory chain were found not only in fibroblasts of the two probands, but surprisingly also in those of their clinically unaffected mother. The respiratory chain defect segregated in transmitochondrial cybrids containing the nucleus of a 143B.206 osteosarcoma cell line and the mutant mtDNA, indicating that the latter was responsible for the biochemical phenotype. DISCUSSION: Our results support the concept that homoplasmic mutations in tRNA genes can be responsible for mitochondrial disorders characterised by extremely variable penetrance. Albeit still unexplained, this phenomenon has important consequences in the nosological characterisation, clinical management, and genetic counselling of mitochondrial disorders.


Subject(s)
Brain Diseases, Metabolic, Inborn/genetics , DNA, Mitochondrial/genetics , Mitochondrial Diseases/genetics , Point Mutation , RNA, Transfer, Ile/genetics , Adolescent , Base Sequence , Brain Diseases, Metabolic, Inborn/diagnosis , Brain Diseases, Metabolic, Inborn/enzymology , Cell Line , Child , DNA Mutational Analysis , Electron Transport Complex IV/metabolism , Female , Fibroblasts/enzymology , Genome, Human , Humans , Infant , Middle Aged , Mitochondrial Diseases/diagnosis , Molecular Sequence Data , Muscle, Skeletal/enzymology , Pedigree , Penetrance , Protein Biosynthesis
13.
Methods Find Exp Clin Pharmacol ; 25(7): 517-20, 2003 Sep.
Article in English | MEDLINE | ID: mdl-14571280

ABSTRACT

When guinea pig eosinophils were incubated with fenoterol, a beta2-agonist, for 120 min, not only desensitization of beta2-adrenoceptors but also hyperresponsiveness to phosphodiesterase (PDE) inhibitors, such as theophylline and rolipram, was observed. The fenoterol-induced beta2-adrenoceptor desensitization was not affected by pretreatment with either genistein, a broad-spectrum tyrosine kinase inhibitor, or PP2, a specific Src family tyrosine kinase inhibitor. On the other hand, both genistein and PP2 abolished the hyperresponsiveness to PDE inhibitors in beta2-adrenoceptor-desensitized eosinophils. These findings suggested that Src family tyrosine kinases play important roles in the hypersensitization of PDE to PDE inhibitors in beta2-adrenoceptor-desensitized eosinophils.


Subject(s)
Adrenergic beta-Agonists/pharmacology , Eosinophils/drug effects , Fenoterol/pharmacology , Phosphodiesterase Inhibitors/pharmacology , Receptors, Adrenergic, beta-2/drug effects , src-Family Kinases/physiology , Animals , Calcimycin/pharmacology , Cell Degranulation/drug effects , Eosinophil Peroxidase , Eosinophils/enzymology , Eosinophils/physiology , Genistein/pharmacology , Guinea Pigs , In Vitro Techniques , Ionophores/pharmacology , Male , Peroxidases/metabolism , Pyrimidines/pharmacology , Receptors, Adrenergic, beta-2/physiology , Time Factors
14.
J Biol Phys ; 28(3): 539-47, 2002 Sep.
Article in English | MEDLINE | ID: mdl-23345796

ABSTRACT

Cerebellar long-term depression (LTD) at the parallel fiber-Purkinje cell synapses has been proposed to be a neural substrate for classical eyeblink conditioning. Mutant mice lacking the glutamate receptor subunit δ2 (GluRδ2), in which the cerebellar LTD is disrupted, exhibited a severe impairment in the delay eyeblink conditioning with a temporal overlap of CS and US. However, they learned normally trace and delay conditioning without CS-US overlap, suggesting a learning mechanism which does not require the cerebellar LTD.In the present study, we tested possible involvement of the hippocampus in this cerebellar LTD-independent learning. We examined effects of scopolamine and hippocampal lesion on the delay conditioning without CS-US overlap. TheGluRδ2 mutant mice that received scopolamine or aspiration of the dorsalhippocampus together with its overlying cortex exhibited a severe impairment in learning, while the control mutant mice that received saline or aspiration of the overlying cortex learned normally. In contrast, wild-type mice that received either treatment learned as normally as the control wild-type mice. These results suggest that the hippocampus is essential in the cerebellar LTD-independent learning in the GluRδ2 mutant mice, indicating a newrole of hippocampus in the paradigm with a short trace interval.

15.
FEBS Lett ; 508(3): 423-6, 2001 Nov 23.
Article in English | MEDLINE | ID: mdl-11728465

ABSTRACT

Blepharismins are polycyclic quinones found in the pigment granules of the ciliated protozoan, Blepharisma. Exposure to purified blepharismins results in lethal damage to several other ciliates. We here report that, at cytotoxic concentrations, blepharismins formed cation-selective channels in planar phospholipid bilayer membranes. The channels formed in a diphytanoylphosphatidylcholine bilayer had a K(+)/Cl(-) permeability ratio of 6.6:1. Single channel recordings revealed the conductance to be quite heterogeneous, ranging from 0.2 to 2.8 nS in solutions containing 0.1 M KCl, possibly reflecting different states of aggregation of blepharismin. Our observations suggest that channel formation is a cytotoxic mechanism of blepharismin's action against predatory protozoa.


Subject(s)
Ciliophora/metabolism , Ion Channels/metabolism , Perylene/analogs & derivatives , Perylene/metabolism , Animals , Chlorides/metabolism , Electric Conductivity , Electrophysiology , Lipid Bilayers , Permeability , Perylene/pharmacology , Phosphatidylcholines , Potassium/metabolism
16.
Eur J Neurosci ; 14(9): 1515-21, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11722613

ABSTRACT

Mice lacking the glutamate receptor subunit delta2 (GluRdelta2) are deficient in cerebellar long-term depression (LTD) at the parallel fibre-Purkinje cell synapses. We conducted delay and trace eyeblink conditioning with these mice, using various temporal intervals between the conditioned stimulus (CS) and unconditioned stimulus (US). During trace conditioning in which a stimulus-free trace interval (TI) of 250, 100 or 50 ms intervened between the 352-ms tone CS and 100-ms US, GluRdelta2-mutant mice learned as successfully as wild-type mice. Even in the paradigm with TI = 0 ms, in which the end of CS and onset of US are simultaneous, there was no difference between the GluRdelta2-mutant and wild-type mice in their acquisition of a conditioned response. However, in the delay paradigm in which the 452-ms CS overlapped temporally with the coterminating 100-ms US, GluRdelta2-mutant mice exhibited severe learning impairment. The present study together with our previous work [Kishimoto, Y., Kawahara, S., Suzuki, M., Mori, H., Mishina, M. & Kirino, Y. (2001) Eur. J. Neurosci., 13, 1249-1254], indicates that cerebellar LTD-independent learning is possible in paradigms without temporal overlap between the CS and US. On the other hand, GluRdelta2 and cerebellar LTD are essential for learning when there is CS-US temporal overlap, suggesting that the cerebellar neural substrates underlying eyeblink conditioning may change, depending on the temporal overlap of the CS and US.


Subject(s)
Cerebellum/metabolism , Conditioning, Eyelid/physiology , Neural Inhibition/genetics , Receptors, Glutamate/deficiency , Synapses/genetics , Synaptic Transmission/genetics , Animals , Cerebellum/cytology , Electromyography , Genotype , Glutamic Acid/metabolism , Learning/physiology , Mice , Mice, Knockout , Muscle Contraction/physiology , Neural Pathways/cytology , Neural Pathways/metabolism , Neurons/cytology , Neurons/metabolism , Reaction Time/genetics , Receptors, Glutamate/genetics , Synapses/metabolism , Time Factors
17.
Neuroreport ; 12(15): 3349-52, 2001 Oct 29.
Article in English | MEDLINE | ID: mdl-11711884

ABSTRACT

The age effect on classical eyeblink conditioning in unrestrained mice (C57BL/6J strain) was evaluated. Mice were trained at one of three age periods (8, 45-50 or 85-90 weeks). In the delay paradigm, significant learning deficits were evident in the 85-90 week-old group, but no deficits were observed in the behavior of the 45-50 week-old group. On the other hand, in the trace paradigm with a stimulus-free trace interval of 500 ms, significant deficits became apparent at the age of 45-50 weeks. These results indicate that trace eyeblink conditioning is more susceptible to age-related deterioration of memory in mice than delay eyeblink conditioning.


Subject(s)
Aging/physiology , Cerebellum/physiology , Conditioning, Eyelid/physiology , Hippocampus/physiology , Memory Disorders/physiopathology , Reaction Time/physiology , Animals , Electric Stimulation , Male , Mice , Mice, Inbred C57BL , Motor Activity/physiology , Reflex, Startle/physiology
18.
Brain Res ; 921(1-2): 98-105, 2001 Dec 07.
Article in English | MEDLINE | ID: mdl-11720715

ABSTRACT

Synchronous oscillations in olfactory systems have been thought to play critical roles in encoding olfactory information. However, their role in determining behavior is unknown. As a first step toward understanding the decoding process of coherent oscillation, we looked for a neuron in the terrestrial slug Limax marginatus that receives output signals from the procerebrum (PC), which is the olfactory center of Limax. We identified a neuron in the metacerebrum that extends its neurites into both the PC and the metacerebrum, and named it the metacerebro-procerebral neuron (MPN). The MPN exhibited a membrane potential oscillation that was synchronous with the local field potential oscillation in the PC. When we cut the PC off, the membrane potential oscillation of the MPN disappeared. Numerous varicosities were found on the neurites in the metacerebrum, while no varicosities were found on the neurites inside the PC. From these morphological and physiological results, we conclude that the MPN is an output neuron from the PC. The MPN also receives monosynaptic inputs from the superior and inferior tentacle nerves. The MPN thus may receive olfactory information from two pathways, one directly from the sensory organ and the other by way of the PC, possibly functioning to integrate them.


Subject(s)
Biological Clocks/physiology , Central Nervous System/cytology , Ganglia, Invertebrate/cytology , Lysine/analogs & derivatives , Mollusca/cytology , Neurons/cytology , Olfactory Pathways/cytology , Animals , Carbocyanines , Central Nervous System/drug effects , Central Nervous System/physiology , Electric Stimulation , Excitatory Postsynaptic Potentials/drug effects , Excitatory Postsynaptic Potentials/physiology , Fluorescent Dyes , Ganglia, Invertebrate/drug effects , Ganglia, Invertebrate/physiology , Glutamic Acid/pharmacology , Membrane Potentials/drug effects , Membrane Potentials/physiology , Mollusca/physiology , Neurites/physiology , Neurites/ultrastructure , Neurons/drug effects , Neurons/physiology , Olfactory Pathways/drug effects , Olfactory Pathways/physiology , Presynaptic Terminals/physiology , Presynaptic Terminals/ultrastructure , Reaction Time/drug effects , Reaction Time/physiology , Smell/drug effects , Smell/physiology , Synaptic Transmission/drug effects , Synaptic Transmission/physiology
19.
Neuropharmacology ; 41(5): 618-28, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11587717

ABSTRACT

N-methyl-D-aspartate (NMDA) receptors are involved in synaptic plasticity and play a critical role in learning and memory. We investigated the effects of the noncompetitive NMDA receptor antagonist (+)MK-801 on classical eyeblink conditioning of mice, using various interstimulus intervals between the conditioned stimulus (CS) and unconditioned stimulus (US). A tone was used for the CS and a periorbital shock was used for the US. In the delay paradigm, in which the US coterminated with the CS or started immediately after CS offset, the effect of (+)MK-801 (0.1mg/kg, i.p.) was a slight impairment in the acquisition of the conditioned response (CR). During subsequent CS-alone trials, the responses of (+)MK-801-injected mice were extinguished as easily as those of saline-injected mice. In the trace paradigm, (+)MK-801 impaired acquisition of the CR with a trace interval of 250 ms more than it did with a trace interval of 100 ms, and more than in the delay paradigm. (+)MK-801 injected after acquisition of 250-ms trace conditioning did not impair expression or extinction of the CR. These results suggest that NMDA receptors are involved in acquisition of the CR during longer trace interval conditioning more than during shorter trace interval conditioning or delay conditioning, and that their contribution to extinction is much smaller than their contribution to acquisition in mouse eyeblink conditioning.


Subject(s)
Blinking/drug effects , Conditioning, Eyelid/drug effects , Dizocilpine Maleate/pharmacology , Excitatory Amino Acid Antagonists/pharmacology , Receptors, N-Methyl-D-Aspartate/antagonists & inhibitors , Animals , Blinking/physiology , Conditioning, Eyelid/physiology , Extinction, Psychological/drug effects , Extinction, Psychological/physiology , Male , Mice , Mice, Inbred C57BL , Receptors, N-Methyl-D-Aspartate/physiology , Reflex, Startle/drug effects , Reflex, Startle/physiology
20.
Neuroreport ; 12(13): 2919-22, 2001 Sep 17.
Article in English | MEDLINE | ID: mdl-11588603

ABSTRACT

To elucidate the functional role of phospholipase Cbeta4 (PLCbeta4), which is highly expressed in the Purkinje cells of the rostral cerebellum, cerebellar long-term depression (LTD) and delay and trace eyeblink conditioning were investigated in PLCbeta4-deficient mice. Rostral cerebellar LTD and delay eyeblink conditioning were severely impaired, whereas trace eyeblink conditioning was not. These results indicate that PLCbeta4 is essential for LTD in the rostral cerebellum and delay conditioning, but not trace conditioning. Rostral cerebellar LTD may be required as a neural substrate for delay conditioning, but is not required for trace conditioning.


Subject(s)
Afferent Pathways/metabolism , Conditioning, Eyelid/physiology , Isoenzymes/deficiency , Long-Term Potentiation/physiology , Neural Inhibition/physiology , Purkinje Cells/metabolism , Reaction Time/physiology , Type C Phospholipases/deficiency , Afferent Pathways/cytology , Animals , Electromyography , Excitatory Postsynaptic Potentials/genetics , Genotype , Isoenzymes/genetics , Mice , Mice, Knockout , Muscle Contraction/genetics , Organ Culture Techniques , Patch-Clamp Techniques , Phospholipase C beta , Purkinje Cells/cytology , Synapses/genetics , Synaptic Transmission/genetics , Type C Phospholipases/genetics
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