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1.
Front Behav Neurosci ; 16: 867958, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36172466

RESUMO

Parkinson's disease (PD) is a progressive, degenerative disease that affects nearly 10 million people worldwide. Hallmark limb motor signs and dopamine depletion have been well studied; however, few studies evaluating early stage, prodromal biology exist. Pink1-/- rats, a rodent model of PD mitochondrial dysfunction, exhibit early stage behavioral deficits, including vocal communication and anxiety, that progress during mid-to-late adulthood (6-12 months of age). Yet, the biological pathways and mechanisms that lead to prodromal dysfunction are not well understood. This study investigated the Pink1-/- rat in young adulthood (2 months of age). Mixed sex groups of Pink1-/- rats and wildtype (WT) controls were assayed for limb motor, anxiety, and vocal motor behaviors. A customized NanoString CodeSet, based on genetic work in later adulthood, was used to probe for the up regulation of genes involved in disease pathways and inflammation within the brainstem and vocal fold muscle. In summary, the data show sex- and genotype-differences in limb motor, anxiety, and vocal motor behaviors. Specifically, female Pink1-/- rats demonstrate less anxiety-like behavior compared to male Pink1-/- rats and female rats show increased locomotor activity compared to male rats. Pink1-/- rats also demonstrate prodromal ultrasonic vocalization dysfunction across all acoustic parameters and sex differences were present for intensity (loudness) and peak frequency. These data demonstrate a difference in phenotype in the Pink1-/- model. Tuba1c transcript level was identified as a key marker negatively correlated to ultrasonic vocalization at 2 months of age. Identifying genes, such as Tuba1c, may help determine early predictors of PD pathology in the Pink1-/- rat and serve as targets for future drug therapy studies.

2.
Analyst ; 136(11): 2270-6, 2011 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-21509366

RESUMO

For sectioned biologic tissues, atomic force microscopy (AFM) topographic images alone hardly provide adequate information leading to revealing biological structures. We demonstrate that phase imaging in amplitude-modulation AFM is a powerful tool in mapping structures present on the surface of unfixed rat brains sections. The contrast in phase images is originated from the difference in mechanical properties between biological structures. Visualization of the native state of biological structures by way of their mechanical properties provides a complementary technique to more traditional imaging techniques such as optical and electron microscopy.


Assuntos
Encéfalo/ultraestrutura , Microscopia de Força Atômica/métodos , Animais , Encéfalo/anatomia & histologia , Lipídeos/análise , Masculino , Microscopia de Força Atômica/instrumentação , Ratos , Ratos Long-Evans , Espectrometria de Massa de Íon Secundário
3.
J Vet Cardiol ; 23: 88-95, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31174733

RESUMO

An 8-month-old intact female pug was presented for evaluation and possible balloon valvuloplasty (BV) for severe aortic stenosis. A bicuspid, severely stenotic aortic valve of type 3 morphology with a supravalvar stenosis component was diagnosed, consistent with the diagnosis of atypical Shone's complex. There was severe concentric hypertrophy of the left ventricle, with increased echogenicity of the myocardium nearest to the endocardial border. Mild left atrial enlargement was observed. Selective angiography and transesophageal echocardiography revealed an enlarged and relatively tortuous ascending aorta. The changes to the ascending aorta and the anatomy of the lesion made retrograde access to the left ventricle challenging. Ultimately, BV was successful using a pediatric valvuloplasty balloon catheter and rapid right ventricular pacing, and the pressure gradient across the aortic valve was decreased by more than 50% compared with preoperative measurements. Although valvar aortic stenosis is rare in veterinary medicine, this report highlights the potential challenges and feasibility of BV for this disease.


Assuntos
Estenose Aórtica Supravalvular/veterinária , Valva Aórtica/anormalidades , Valvuloplastia com Balão/veterinária , Doenças do Cão/terapia , Doenças das Valvas Cardíacas/veterinária , Animais , Estenose Aórtica Supravalvular/diagnóstico por imagem , Estenose Aórtica Supravalvular/terapia , Valva Aórtica/diagnóstico por imagem , Doença da Válvula Aórtica Bicúspide , Doenças do Cão/diagnóstico por imagem , Cães , Ecocardiografia/veterinária , Ecocardiografia Transesofagiana/veterinária , Feminino , Doenças das Valvas Cardíacas/diagnóstico por imagem , Doenças das Valvas Cardíacas/terapia
4.
J Small Anim Pract ; 59(9): 547-552, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30022475

RESUMO

OBJECTIVES: To investigate the outcome of dogs with central nervous system lymphoma. MATERIALS AND METHODS: A multi-center, retrospective, observational study was conducted by reviewing medical records of 18 cases of central nervous system lymphoma from seven institutions. RESULTS: Diagnosis of lymphoma was made through cerebrospinal fluid analysis, histopathology, flow cytometry of the cerebrospinal fluid, and cytology of cerebrospinal fluid, lymph node or spleen with correlated imaging. A total of 15 of 18 dogs received specific treatment other than prednisone. Three dogs underwent chemotherapy and radiation therapy after surgical decompression, five dogs underwent chemotherapy, two dogs underwent radiation therapy after surgical decompression, three dogs underwent chemotherapy after surgical decompression and two dogs underwent radiation therapy and chemotherapy. Only one dog received prednisone, and two dogs did not receive any treatment. Overall, the median survival time was 171 days (range 1 to 1942 days). CLINICAL SIGNIFICANCE: Dogs receiving any type of treatment for central nervous system lymphoma lived longer than cases described in previous historical reports. Further studies are needed to elucidate the importance of specific treatment modalities.


Assuntos
Neoplasias do Sistema Nervoso Central/veterinária , Doenças do Cão/terapia , Linfoma/veterinária , Animais , Anti-Inflamatórios/administração & dosagem , Neoplasias do Sistema Nervoso Central/diagnóstico , Neoplasias do Sistema Nervoso Central/terapia , Descompressão Cirúrgica/veterinária , Doenças do Cão/diagnóstico , Cães , Feminino , Linfoma/diagnóstico , Linfoma/terapia , Masculino , Prednisona/administração & dosagem , Estudos Retrospectivos , Análise de Sobrevida
5.
Plant Cell ; 8(11): 2015-2031, 1996 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12239374

RESUMO

Subprotoplasts prepared from different regions of rhizoid and thallus cells of Fucus zygotes displayed mechanosensitive plasma membrane channels in cell-attached patch-clamp experiments by using laser microsurgery. In excised patches, this channel was found to be voltage gated, carrying K+ outward and Ca2+ inward, with a relative permeability of Ca2+/K+ of 0.35 to 0.5, and an increased open probability at membrane potentials more positive than -80 mV. No significant difference was found in the density of this channel type from different regions of rhizoid or thallus cells. Hypoosmotic treatment of intact zygotes induced dramatic transient elevations of cytoplasmic Ca2+, initiating at the rhizoid apex and propagating in a wavelike manner to subapical regions. Localized initiation of the Ca2+ transient correlated with greater osmotic swelling at the rhizoid apex compared with other regions of the zygote. Ca2+ transients exhibited a refractory period between successive hypoosmotic shocks, during which additional transients could not be elicited and the ability to osmoregulate was impaired. Buffering the Ca2+ transients with microinjected Br2BAPTA similarly reduced the ability of rhizoid cells to osmoregulate. Ca2+ influx was associated with the initiation of the Ca2+ transient in apical regions, whereas intracellular sources contributed to its propagation. Thus, localized signal transduction is patterned by interactions of the cell wall, plasma membrane, and intracellular Ca2+ stores.

7.
J Environ Radioact ; 140: 30-41, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25461513

RESUMO

The Tertiary Limestone Aquifer (TLA) is one of the major regional hydrogeological systems of southern Australia. Submarine groundwater discharge (SGD) of freshwater from the TLA occurs through spring creeks, beach springs and diffusively through beach sands, but the magnitude of the total flux is not known. Here, a range of potential environmental tracers (including temperature, salinity, (222)Rn, (223)Ra, (224)Ra, (226)Ra, (228)Ra, and (4)He) were measured in potential sources of SGD and in seawater along a 45 km transect off the coastline to evaluate SGD from the TLA. Whilst most tracers had a distinct signature in the sources of water to the coastline, salinity and the radium quartet had the most distinct SGD signal in seawater. A one-dimensional advection-dispersion model was used to estimate the terrestrial freshwater component of SGD (Qfw) using salinity and the recirculated seawater component (Qrsw) using radium activity in seawater. Qfw was estimated at 1.2-4.6 m(3) s(-1), similar in magnitude to previously measured spring creek discharge (∼3 m(3) s(-1)) for the area. This suggests that other terrestrial groundwater discharge processes (beach springs and diffuse discharge through beach sands) were no more than 50% of spring creek discharge. The largest component of total SGD was Qrsw, estimated at 500-1000 m(3) s(-1) and possibly greater. The potential for wave, storm, or buoyancy-driven porewater displacement from the seafloor could explain the large recirculation flux for this section of the Southern Ocean Continental Shelf.


Assuntos
Água Subterrânea/análise , Rádio (Elemento)/análise , Radônio/análise , Austrália
8.
Meat Sci ; 110: 201-11, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26253836

RESUMO

The objective of this study was to determine if maternal energy status during mid-gestation influences the expression of genes regulating muscle and fat development, and muscle characteristics that may impact meat tenderness. Cows grazed dormant, native range (Positive Energy Status [PES]) or were fed at 80% of maintenance energy requirements (Negative Energy Status [NES]) during mid-gestation. Steer offspring were harvested after 21 d in the feedlot (weaning subsample) or after 208 d in the feedlot (final subsample). Greater 21-d tenderness was observed in NES steers, resulting from reduced collagen content in longissimus lumborum steaks. In the semitendinosus, NES steers had greater soluble collagen, and down-regulated expression of MHC-IIA and TIMP-3 at weaning, while MHC-IIA expression was up-regulated in NES steers in the final harvest. Data show mid-gestational maternal energy status may impact offspring tenderness and collagen, but differences were not detected in expression of genes important in myogenesis and adipogenesis in muscle samples obtained from steers at weaning or slaughter.


Assuntos
Metabolismo Energético , Regulação da Expressão Gênica/fisiologia , Carne/normas , Músculo Esquelético/fisiologia , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bovinos , Feminino , Fenômenos Fisiológicos da Nutrição Materna , Gravidez
9.
J Vet Intern Med ; 29(6): 1556-63, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26473515

RESUMO

BACKGROUND: Systemic aspergillosis is a manifestation of Aspergillus sp. infection that can result in central nervous system (CNS) involvement with marked alterations in CNS function. Information regarding the clinical presentation and magnetic resonance imaging (MRI) findings in cases of aspergillosis with CNS involvement is lacking, resulting in a need for better understanding of this disease. HYPOTHESIS/OBJECTIVES: The primary objectives were to describe the clinical features and MRI findings in dogs with CNS aspergillosis. The secondary objectives were to describe clinicopathologic findings and case outcome. ANIMALS: Seven dogs with CNS aspergillosis. METHODS: Archived records from 6 institutions were reviewed to identify cases with MRI of CNS aspergillosis confirmed with serum galactomannan enzyme immunoassay (EIA) testing, culture, or supported by histopathology. Signalment, clinical, MRI, clinicopathologic, histopathologic, and microbiologic findings were recorded and evaluated. RESULTS: Aspergillosis of the CNS was identified in 7 dogs from 3 institutions. The median age was 3 years and six were German Shepherd dogs. Five dogs had signs of vestibular dysfunction as a component of multifocal neurological abnormalities. The MRI findings ranged from normal to abnormal, including hemorrhagic infarction and mass lesions. CONCLUSIONS AND CLINICAL IMPORTANCE: Until now, all reported MRI findings in dogs with CNS aspergillosis have been abnormal. We document that CNS aspergillosis in dogs, particularly German Shepherd dogs, can be suspected based on neurologic signs, whether MRI findings are normal or abnormal. Confirmatory testing with galactomannan EIA, urine, cerebrospinal fluid (CSF) or tissue culture should be performed in cases where aspergillosis is a differential diagnosis.


Assuntos
Aspergilose/veterinária , Infecções Fúngicas do Sistema Nervoso Central/veterinária , Doenças do Cão/patologia , Imageamento por Ressonância Magnética/veterinária , Animais , Antifúngicos/uso terapêutico , Aspergilose/diagnóstico , Aspergilose/patologia , Infecções Fúngicas do Sistema Nervoso Central/patologia , Doenças do Cão/diagnóstico , Cães , Feminino , Masculino
10.
J Anim Sci ; 93(2): 786-93, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25548203

RESUMO

Research has suggested that maternal undernutrition may cause the development of a thrifty phenotype in the offspring, potentially resulting in greater adiposity and reduced muscle mass. These alterations in adipose and muscle development could have lasting impacts on offspring growth, carcass characteristics, and meat quality. However, limited research exists evaluating the impact of maternal energy status on these economically important traits of the offspring. Therefore, the objective of this study was to determine the influence of maternal energy status during midgestation on offspring carcass characteristics and meat quality. To alter maternal energy status, cows either grazed dormant, winter range (positive energy status [PES]) or were fed in a drylot at 80% of the energy requirements for BW maintenance (negative energy status [NES]) during a mean period of 102 ± 10.9 to 193 ± 10.9 d of gestation. Changes in BCS, BW, LM area (LMA), and 12th rib backfat were measured throughout midgestation. At the end of midgestation, cows in the NES group had a reduction (P ≤ 0.05) in BCS, BW, LMA, and 12th rib backfat when compared with PES dams. Cows and calves were managed similarly after midgestation through weaning and calves were managed and fed a common diet through the receiving, backgrounding, and finishing phases in the feedlot. Calves were harvested after 208 d in the feedlot, carcass characteristics were recorded, and strip loins were recovered for analysis of objective color and Warner-Bratzler shear force (WBSF). Maternal energy status had no influence on offspring HCW, dressing percent, LMA, percent KPH, marbling score, percent intramuscular fat, objective color, or WBSF (P > 0.10). Progeny of NES cows tended to have improvements in 12th rib backfat and USDA yield grade (P < 0.10). Greater ratio of marbling score to 12th rib fat thickness and ratio of percent intramuscular fat to 12th rib fat thickness (P < 0.05) were discovered in progeny from cows experiencing a NES during midgestation. These results suggest that maternal energy status during midgestation may impact fat deposition in intramuscular and subcutaneous fat depots without impacting muscle mass.


Assuntos
Animais Recém-Nascidos/fisiologia , Composição Corporal/fisiologia , Bovinos/fisiologia , Metabolismo Energético/fisiologia , Fenômenos Fisiológicos da Nutrição Materna/fisiologia , Carne/normas , Prenhez/fisiologia , Adiposidade/fisiologia , Animais , Animais Recém-Nascidos/crescimento & desenvolvimento , Peso Corporal/fisiologia , Bovinos/crescimento & desenvolvimento , Feminino , Desenvolvimento Fetal/fisiologia , Indústria Alimentícia/normas , Qualidade dos Alimentos , Masculino , Músculo Esquelético/fisiologia , Gravidez
11.
Eur J Cancer ; 26(7): 838-42, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2145908

RESUMO

The pharmacokinetics and metabolism of intravenously infused 14C-fotemustine (about 100 mg/m2) were examined in 2 cancer patients. Plasma levels of radioactivity increased to a maximum of 4.1 and 5.5 micrograms equivalents per g when the infusion stopped then declined triexponentially with mean half-lives of about 1/2, 10 and 80 h for the initial, mid and terminal phases, respectively. Plasma levels of intact drug were lower, with maximum levels of 1.1 and 2.8 micrograms/ml, and declined monophasically with a half-life of about 24 min. Plasma clearance was high (1426 and 764 ml/min) with the volume of distribution based on areas of 47.7 and 26.4 l. Most of the radioactivity was eliminated in urine (50.1 and 61.3%) over 7 days with smaller amounts in the feces (6.8 and 0.3%) and only minimal quantities (under 0.1%) as expired carbon dioxide. Metabolites of fotemustine were identified as chloroethanol and N-nitroso-1-imidazolone-ethyl-diethylphosphonate in plasma and as 1-hydantoin-ethyl-diethyl-phosphonate and acetic acid in urine.


Assuntos
Antineoplásicos/farmacocinética , Compostos de Nitrosoureia/farmacocinética , Compostos Organofosforados/farmacocinética , Neoplasias Ovarianas/metabolismo , Neoplasias da Próstata/metabolismo , Idoso , Radioisótopos de Carbono , Etilenocloroidrina/sangue , Fezes/química , Feminino , Meia-Vida , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
12.
Eur J Cancer ; 32A(11): 1888-92, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8943670

RESUMO

139 peri- and postmenopausal women with advanced or recurrent breast cancer who had not received prior hormonal therapy were randomised in an open, cross-over study comparing the synthetic progestogen megestrol acetate with tamoxifen. The response rate (CR/PR) to megestrol acetate (25%; 95% confidence interval (CI) 15-35%) was not significantly different from that produced by tamoxifen (33%, CI 22-44%). Time-to-treatment failure was also similar in the two groups. Cross-over treatment was given on progression in 76 cases. Cross-over response (CR/PR) was seen in 3 of 35 patients (9%) receiving megestrol acetate as second-line therapy and in 6 of 41 patients (15%) receiving tamoxifen second-line. There was no significant difference in survival between the groups (P = 0.17) with median survival times of 24 and 32 months for the megestrol acetate and tamoxifen groups, respectively. The toxicity profile of the two drugs was different, although significant toxicity was rare with either agent. Megestrol acetate is an effective treatment for advanced breast cancer in older women when used either as first- or second-line treatment. Cross-over response is seen following both treatments. Given that most patients now receive tamoxifen as adjuvant treatment, megestrol acetate would appear to be one of the logical choices for patients who find the side-effects of tamoxifen unacceptable and for those who relapse on tamoxifen with further hormone therapy being clinically indicated.


Assuntos
Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Acetato de Megestrol/uso terapêutico , Tamoxifeno/uso terapêutico , Adulto , Idoso , Antineoplásicos Hormonais/efeitos adversos , Neoplasias da Mama/patologia , Estudos Cross-Over , Feminino , Humanos , Pessoa de Meia-Idade , Metástase Neoplásica , Taxa de Sobrevida , Tamoxifeno/efeitos adversos , Fatores de Tempo , Falha de Tratamento
13.
Breast ; 12(2): 156-7, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-14659347

RESUMO

Increased incidence of malignancies within aviators is well documented. Commercial female flyers have been found to have a higher risk of developing breast cancer. However, there has not been any report of male breast cancer related to flying either alone or where malignant melanoma and other primary cancers are also associated. We report two male World War II, British Royal Air Force pilots with primary breast carcinoma associated with two other primary cancer sites.


Assuntos
Aviação , Neoplasias da Mama Masculina/diagnóstico , Carcinoma Ductal de Mama/patologia , Idoso , Biópsia por Agulha , Neoplasias da Mama Masculina/terapia , Carcinoma Ductal de Mama/terapia , Quimioterapia Adjuvante , Seguimentos , Humanos , Masculino , Mastectomia/métodos , Estadiamento de Neoplasias , Medição de Risco , Resultado do Tratamento , Guerra
14.
J Pharm Sci ; 68(8): 1063-4, 1979 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-480165

RESUMO

Photolytic decomposition of indapamide (I) in nitrogen-flushed methanol yields 3-sulfamoyl-4-chlorobenzamide (II), 2-methylindoline (III), semicarbazide (IV), and 1-(N-formamido)-2-methylindoline (V); in oxygen-flushed methanol, II--V, 1-aminocarboxymethyl-2-methylindoline (VI), 3-sulfamoyl-4-chlorobenzoic acid (VII), methyl-3-sulfamoyl-4-chlorobenzoate (VIII), and 2-(N-acetamido)-benzoic acid (IX) are formed. A comparison is made with thermal decomposition of I.


Assuntos
Diuréticos , Indapamida , Fenômenos Químicos , Química , Fotólise
15.
Lipids ; 10(9): 535-41, 1975 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-170488

RESUMO

Studies of beta-monoglyceride multilayers were carried out using a variety of spin probes. Effects of variables such as chain length, unsaturation, and branching on organization of acyl chains in lipids of model membranes were assessed. In addition, effects of added cholesterol on membrane order were determined. Results indicated that pure beta-monolaurin yields highly ordered films, whereas, unsaturated glycerides such as beta-monoolein, beta-monolinolein, and analogous lecithins yield fluid films. Branched monoglycerides behaved similarly to beta-monoolein, suggesting that branching in acyl chains is an effective substitute for unsaturation in maintaining membrane integrity. Multilayers of beta-monoglycerides exhibited similar properties to those of more complex lipids such as phospholipids. beta-Monoglycerides, by virtue of the presence of a single acyl chain, provided a relatively simple and effective alternative to the use of phospholipids in studies of membrane architecture.


Assuntos
Glicerídeos , Membranas Artificiais , Fosfatidilcolinas , Sítios de Ligação , Colesterol , Espectroscopia de Ressonância de Spin Eletrônica , Modelos Biológicos , Conformação Molecular , Fosfolipídeos , Relação Estrutura-Atividade
16.
J Bone Joint Surg Br ; 59-B(4): 393-7, 1977 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-925047

RESUMO

In fifty-six patients with ankylosing spondylitis three types of arthroplasty had been performed in ninety-nine hips. Forty-one of the patients were men and fifteen were women, their average age at operation being forty-two years. Primary pseudarthrosis produced well-satisfied patients, but only a fair result in five hips, whereas cup arthroplasty resulted in a poor outcome for eight hips, all of which needed revision. Total replacement of eighty-six hips, however, led to 73 per cent being graded as good or excellent up to ten years later. The main complications were deep infection of five hips, para-articular ossification around nine hips (six leading to bony ankylosis), and fibrous ankylosis of six hips.


Assuntos
Artroplastia , Quadril/cirurgia , Espondilite Anquilosante/cirurgia , Adulto , Anquilose/etiologia , Artroplastia/efeitos adversos , Artroplastia/métodos , Doenças Ósseas/etiologia , Feminino , Articulação do Quadril , Humanos , Infecções/etiologia , Prótese Articular , Masculino
17.
J Bone Joint Surg Br ; 58-B(4): 485-7, 1976 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1018036

RESUMO

The results of excision of the head of the radius in forty-four elbows affected by rheumatoid arthritis are presented. Relief of pain was obtained in 90 per cent and an increase in the range of flexion and extension was seen in 70 per cent. Involvement of the humero-ulnar joint seen radiologically is no contra-indication to the operation; simple excision of the radial head often gives gratifying results; In our experience the relief of pain and increased range of movement have greatly reduced the need for total replacement arthroplasty.


Assuntos
Artrite Reumatoide/cirurgia , Rádio (Anatomia)/cirurgia , Adulto , Artrite Reumatoide/reabilitação , Articulação do Cotovelo , Seguimentos , Humanos , Masculino , Movimento , Sinovectomia
18.
Neuroscience ; 249: 31-42, 2013 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-23022220

RESUMO

The incidence of anxiety, mood, substance abuse disorders and schizophrenia increases during adolescence. Epidemiological evidence confirms that exposure to stress during sensitive periods of development can create vulnerabilities that put genetically predisposed individuals at increased risk for psychiatric disorders. Neuregulin 1 (NRG1) is a frequently identified schizophrenia susceptibility gene that has also been associated with the psychotic features of bipolar disorder. Previously, we established that Type II NRG1 is expressed in the hypothalamic-pituitary-adrenal (HPA) axis neurocircuitry. We also found, using a line of Nrg1 hypomorphic rats (Nrg1(Tn)), that genetic disruption of Type II NRG1 results in altered HPA axis function and environmental reactivity. The present studies used the Nrg1(Tn) rats to test whether Type II NRG1 gene disruption and chronic stress exposure during adolescence interact to alter adult anxiety- and fear-related behaviors. Male and female Nrg1(Tn) and wild-type rats were exposed to chronic variable stress (CVS) during mid-adolescence and then tested for anxiety-like behavior, cued fear conditioning and basal corticosterone secretion in adulthood. The disruption of Type II NRG1 alone significantly impacts rat anxiety-related behavior by reversing normal sex-related differences and impairs the ability to acquire cued fear conditioning. Sex-specific interactions between genotype and adolescent stress also were identified such that CVS-treated wild-type females exhibited a slight reduction in anxiety-like behavior and basal corticosterone, while CVS-treated Nrg1(Tn) females exhibited a significant increase in cued fear extinction. These studies confirm the importance of Type II NRG1 in anxiety and fear behaviors and point to adolescence as a time when stressful experiences can shape adult behavior and HPA axis function.


Assuntos
Ansiedade/genética , Ansiedade/metabolismo , Medo/fisiologia , Neuregulina-1/deficiência , Neuregulina-1/genética , Glândulas Suprarrenais/fisiologia , Fatores Etários , Animais , Ansiedade/psicologia , Doença Crônica , Medo/psicologia , Feminino , Hipotálamo/fisiologia , Masculino , Hipófise/fisiologia , Ratos , Ratos Endogâmicos F344 , Ratos Transgênicos
19.
Physiol Behav ; 104(2): 205-14, 2011 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-21092742

RESUMO

Exposure to stress can result in an increased risk for psychiatric disorders, especially among genetically predisposed individuals. Neuregulin 1 (NRG1) is a susceptibility gene for schizophrenia and is also associated with psychotic bipolar disorder. In the rat, the neurons of the hypothalamic paraventricular nucleus show strong expression of Nrg1 mRNA. In patients with schizophrenia, a single nucleotide polymorphism in the 5' region of NRG1 interacts with psychosocial stress to affect reactivity to expressed emotion. However, there is virtually no information on the role of NRG1 in hypothalamic-pituitary-adrenal axis function, and whether the protein is expressed in the paraventricular nucleus is unknown. The present studies utilize a unique line of Nrg1 hypomorphic rats (Nrg1(Tn)) generated by gene trapping with the Sleeping Beauty transposon. We first established that the Nrg1(Tn) rats displayed reduced expression of both the mRNA and protein corresponding to the Type II NRG1 isoform. After confirming, using wild type animals, that Type II NRG1 is expressed in the neurocircuitry involved in regulating hypothalamic-pituitary-adrenal axis responses to environmental stimuli, the Nrg1(Tn) rats were then used to test the hypothesis that altered expression of Type II NRG1 disrupts stress regulation and reactivity. In support of this hypothesis, Nrg1(Tn) rats have disrupted basal and acute stress recovery corticosterone secretion, differential changes in expression of glucocorticoid receptors in the pituitary, paraventricular nucleus and hippocampus, and a failure to habituate to an open field. Together, these findings point to NRG1 as a potential novel regulator of neuroendocrine responses to stress as well as behavioral reactivity.


Assuntos
Comportamento Animal/fisiologia , Meio Ambiente , Sistema Hipotálamo-Hipofisário/metabolismo , Neuregulina-1/genética , Neuregulina-1/metabolismo , Sistema Hipófise-Suprarrenal/metabolismo , Análise de Variância , Animais , Animais Recém-Nascidos , Corticosterona/metabolismo , Comportamento Exploratório/fisiologia , Feminino , Glucocorticoides/metabolismo , Habituação Psicofisiológica/fisiologia , Masculino , Comportamento Materno/fisiologia , Mutação/genética , RNA Mensageiro/metabolismo , Radioimunoensaio/métodos , Ratos , Ratos Endogâmicos F344 , Ratos Transgênicos , Receptores de Mineralocorticoides/metabolismo , Restrição Física/métodos
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