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1.
Eur J Pediatr ; 182(5): 2057-2066, 2023 May.
Article in English | MEDLINE | ID: mdl-36905437

ABSTRACT

PURPOSE:  to review recent literature concerning long-term health issues and transitional care in esophageal atresia (EA) patients. PubMed, Scopus, Embase and Web of Science databases were screened for studies regarding EA patients aged more than or equal to 11 years, published between August 2014 and June 2022. Sixteen studies involving 830 patients were analyzed. Mean age was 27.4 years (range 11-63). EA subtype distribution was: type C (48.8%), A (9.5%), D (1.9%), E (0.5%) and B (0.2%). 55% underwent primary repair, 34.3% delayed repair, 10.5% esophageal substitution. Mean follow-up was 27.2 years (range 11-63). Long-term sequelae were: gastro-esophageal reflux (41.4%), dysphagia (27.6%), esophagitis (12.4%), Barrett esophagus (8.1%), anastomotic stricture (4.8%); persistent cough (8.7%), recurrent infections (4.3%) and chronic respiratory diseases (5.5%). Musculo-skeletal deformities were present in 36 out of 74 reported cases. Reduced weight and height were detected in 13.3% and 6% cases, respectively. Impaired quality of life was reported in 9% of patients; 9.6% had diagnosis or raised risk of mental disorders. 10.3% of adult patients had no care provider. Meta-analysis was conducted on 816 patients. Estimated prevalences are: GERD 42.4%, dysphagia 57.8%, Barrett esophagus 12.4%, respiratory diseases 33.3%, neurological sequelae 11.7%, underweight 19.6%. Heterogeneity was substantial (> 50%).   Conclusion: EA patients must continue follow-up beyond childhood, with a defined transitional-care path by a highly specialized multidisciplinary team due to the multiple long-term sequelae. WHAT IS KNOWN: • Survival rates of esophageal atresia patients is now more than 90% thanks to the improvements in surgical techniques and intensive care, therefore patients' needs throughout adolescence and adulthood must be taken into account. WHAT IS NEW: • This review, by summarizing recent literature concerning long term sequelae of esophageal atresia, may contribute to raise awareness on the importance of defining standardized protocols of transitional and adulthood care for esophageal atresia patients.


Subject(s)
Barrett Esophagus , Deglutition Disorders , Esophageal Atresia , Gastroesophageal Reflux , Transitional Care , Adolescent , Adult , Child , Humans , Middle Aged , Young Adult , Barrett Esophagus/complications , Disease Progression , Esophageal Atresia/complications , Esophageal Atresia/surgery , Esophageal Atresia/diagnosis , Follow-Up Studies , Gastroesophageal Reflux/complications , Gastroesophageal Reflux/diagnosis , Gastroesophageal Reflux/epidemiology , Quality of Life
2.
Cell Rep ; 36(5): 109465, 2021 08 03.
Article in English | MEDLINE | ID: mdl-34348146

ABSTRACT

Neuromodulation mediated by synaptically released endogenous transmitters acting in G-protein-coupled receptors (GPCRs) is slow primarily because of multistep downstream signaling. What is less well understood is the spatial and temporal kinetics of transmitter and receptor interaction. The present work uses the combination of the dopamine sensor, dLight, to detect the spatial release and diffusion of dopamine and a caged form of a D2-dopamine receptor antagonist, CyHQ-sulpiride, to rapidly block the D2 autoreceptors. Photoactivation of the CyHQ-sulpiride blocks receptors in milliseconds such that the time course of dopamine/receptor interaction is mapped onto the downstream signaling. The results show that highly localized release, but not dopamine diffusion, defines the time course of the functional interaction between dopamine and D2 autoreceptors, which determines downstream inhibition.


Subject(s)
Dopamine/metabolism , Receptors, Dopamine D2/metabolism , Synapses/metabolism , Animals , Extracellular Space/metabolism , Female , G Protein-Coupled Inwardly-Rectifying Potassium Channels/metabolism , Kinetics , Light , Male , Mice, Inbred C57BL , Photolysis , Time Factors
3.
Mov Disord ; 36(3): 729-739, 2021 03.
Article in English | MEDLINE | ID: mdl-33200438

ABSTRACT

BACKGROUND: We describe a 4-generation Dutch pedigree with a unique dominantly inherited clinical phenotype of a combined progressive chorea and cervical dystonia carrying a novel heterozygous dopamine D2 receptor (DRD2) variant. OBJECTIVES: The objective of this study was to identify the genetic cause of the disease and to further investigate the functional consequences of the genetic variant. METHODS: After detailed clinical and neurological examination, whole-exome sequencing was performed. Because a novel variant in the DRD2 gene was found as the likely causative gene defect in our pedigree, we sequenced the DRD2 gene in a cohort of 121 Huntington-like cases with unknown genetic cause (Germany). Moreover, functional characterization of the DRD2 variant included arrestin recruitment, G protein activation, and G protein-mediated inhibition of adenylyl cyclase determined in a cell model, and G protein-regulated inward-rectifying potassium channels measured in midbrain slices of mice. RESULT: We identified a novel heterozygous variant c.634A > T, p.Ile212Phe in exon 5 of DRD2 that cosegregated with the clinical phenotype. Screening of the German cohort did not reveal additional putative disease-causing variants. We demonstrated that the D2S/L -I212 F receptor exhibited increased agonist potency and constitutive activation of G proteins in human embryonic kidney 239 cells as well as significantly reduced arrestin3 recruitment. We further showed that the D2S -I212 F receptor exhibited aberrant receptor function in mouse midbrain slices. CONCLUSIONS: Our results support an association between the novel p.Ile212Phe variant in DRD2, its modified D2 receptor activity, and the hyperkinetic movement disorder reported in the 4-generation pedigree. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.


Subject(s)
Chorea , Dystonia , Animals , Chorea/genetics , Gain of Function Mutation , Germany , Mice , Phenotype , Receptors, Dopamine D2/genetics
4.
Ther Clin Risk Manag ; 16: 181-187, 2020.
Article in English | MEDLINE | ID: mdl-32184610

ABSTRACT

Uncontrolled asthma continues to be a problem for many patients with moderate-to-severe allergic asthma. Dupilumab, which blocks the receptors for interleukin-4 and interleukin-13, has been effective in reducing asthma exacerbations, improving forced expiratory volume in one second (FEV1), and reducing oral corticosteroid use. When selecting patients for dupilumab, it is important to consider entry criteria for the original studies, subgroups that have responded best, and the presence of comorbid diseases that may also respond to dupilumab. Factors that were considered when selecting patients likely to respond to dupilumab in asthma studies include: failure of moderate or high dose inhaled steroids in combination with an additional controller medication, baseline FEV1 reversibility of 12% or greater, and Asthma Control Questionnaire > 1.5. The baseline characteristics that predicted a better response to dupilumab included blood eosinophils > 150 cells/mm3 and fractional exhaled nitric oxide > 25 parts per billion. Comorbidities that may also respond to treatment with dupilumab include atopic dermatitis, chronic rhinosinusitis, and allergic rhinitis. A combination of these factors should be considered when selecting the patients most likely to benefit from dupilumab.

5.
Elife ; 82019 09 05.
Article in English | MEDLINE | ID: mdl-31486769

ABSTRACT

Action potentials trigger neurotransmitter release at active zones, specialized release sites in axons. Many neurons also secrete neurotransmitters or neuromodulators from their somata and dendrites. However, it is unclear whether somatodendritic release employs specialized sites for release, and the molecular machinery for somatodendritic release is not understood. Here, we identify an essential role for the active zone protein RIM in stimulated somatodendritic dopamine release in the midbrain. In mice in which RIMs are selectively removed from dopamine neurons, action potentials failed to evoke significant somatodendritic release detected via D2 receptor-mediated currents. Compellingly, spontaneous dopamine release was normal upon RIM knockout. Dopamine neuron morphology, excitability, and dopamine release evoked by amphetamine, which reverses dopamine transporters, were also unaffected. We conclude that somatodendritic release employs molecular scaffolds to establish secretory sites for rapid dopamine signaling during firing. In contrast, basal release that is independent of action potential firing does not require RIM.


Subject(s)
ATP-Binding Cassette Transporters/metabolism , Dendrites/metabolism , Dopamine/metabolism , Mesencephalon/metabolism , Action Potentials , Animals , Mice , Receptors, Dopamine D2/metabolism , Synaptic Transmission
6.
Lancet Planet Health ; 3(3): e124-e131, 2019 03.
Article in English | MEDLINE | ID: mdl-30904111

ABSTRACT

BACKGROUND: Ongoing climate change might, through rising temperatures, alter allergenic pollen biology across the northern hemisphere. We aimed to analyse trends in pollen seasonality and pollen load and to establish whether there are specific climate-related links to any observed changes. METHODS: For this retrospective data analysis, we did an extensive search for global datasets with 20 years or more of airborne pollen data that consistently recorded pollen season indices (eg, duration and intensity). 17 locations across three continents with long-term (approximately 26 years on average) quantitative records of seasonal concentrations of multiple pollen (aeroallergen) taxa met the selection criteria. These datasets were analysed in the context of recent annual changes in maximum temperature (Tmax) and minimum temperature (Tmin) associated with anthropogenic climate change. Seasonal regressions (slopes) of variation in pollen load and pollen season duration over time were compared to Tmax, cumulative degree day Tmax, Tmin, cumulative degree day Tmin, and frost-free days among all 17 locations to ascertain significant correlations. FINDINGS: 12 (71%) of the 17 locations showed significant increases in seasonal cumulative pollen or annual pollen load. Similarly, 11 (65%) of the 17 locations showed a significant increase in pollen season duration over time, increasing, on average, 0·9 days per year. Across the northern hemisphere locations analysed, annual cumulative increases in Tmax over time were significantly associated with percentage increases in seasonal pollen load (r=0·52, p=0·034) as were annual cumulative increases in Tmin (r=0·61, p=0·010). Similar results were observed for pollen season duration, but only for cumulative degree days (higher than the freezing point [0°C or 32°F]) for Tmax (r=0·53, p=0·030) and Tmin (r=0·48, p=0·05). Additionally, temporal increases in frost-free days per year were significantly correlated with increases in both pollen load (r=0·62, p=0·008) and pollen season duration (r=0·68, p=0·003) when averaged for all 17 locations. INTERPRETATION: Our findings reveal that the ongoing increase in temperature extremes (Tmin and Tmax) might already be contributing to extended seasonal duration and increased pollen load for multiple aeroallergenic pollen taxa in diverse locations across the northern hemisphere. This study, done across multiple continents, highlights an important link between ongoing global warming and public health-one that could be exacerbated as temperatures continue to increase. FUNDING: None.


Subject(s)
Allergens/analysis , Global Warming , Hot Temperature , Pollen , Asia , Europe , North America , Retrospective Studies , Seasons
7.
Elife ; 62017 11 20.
Article in English | MEDLINE | ID: mdl-29154756

ABSTRACT

The dopamine D2 receptor has two splice variants, D2S (Short) and D2L (Long). In dopamine neurons, both variants can act as autoreceptors to regulate neuronal excitability and dopamine release, but the roles of each variant are incompletely characterized. In a previous study we used viral receptor expression in D2 receptor knockout mice to show distinct effects of calcium signaling on D2S and D2L autoreceptor function (Gantz et al., 2015). However, the cocaine-induced plasticity of D2 receptor desensitization observed in wild type mice was not recapitulated with this method of receptor expression. Here we use mice with genetic knockouts of either the D2S or D2L variant to investigate cocaine-induced plasticity in D2 receptor signaling. Following a single in vivo cocaine exposure, the desensitization of D2 receptors from neurons expressing only the D2S variant was reduced. This did not occur in D2L-expressing neurons, indicating differential drug-induced plasticity between the variants.


Subject(s)
Autoreceptors/metabolism , Cocaine/metabolism , Dopaminergic Neurons/drug effects , Dopaminergic Neurons/physiology , Receptors, Dopamine D2/metabolism , Animals , Mice , Mice, Knockout , Protein Binding , Protein Isoforms/metabolism
8.
Sci Rep ; 7(1): 4379, 2017 06 29.
Article in English | MEDLINE | ID: mdl-28663556

ABSTRACT

Dendritic release of dopamine activates dopamine D2 autoreceptors, which are inhibitory G protein-coupled receptors (GPCRs), to decrease the excitability of dopamine neurons. This study used tagged D2 receptors to identify the localization and distribution of these receptors in living midbrain dopamine neurons. GFP-tagged D2 receptors were found to be unevenly clustered on the soma and dendrites of dopamine neurons within the substantia nigra pars compacta (SNc). Physiological signaling and desensitization of the tagged receptors were not different from wild type receptors. Unexpectedly, upon desensitization the tagged D2 receptors were not internalized. When tagged D2 receptors were expressed in locus coeruleus neurons, a desensitizing protocol induced significant internalization. Likewise, when tagged µ-opioid receptors were expressed in dopamine neurons they too were internalized. The distribution and lack of agonist-induced internalization of D2 receptors on dopamine neurons indicate a purposefully regulated localization of these receptors.


Subject(s)
Autoreceptors/metabolism , Receptors, Dopamine D2/metabolism , Action Potentials , Animals , Autoreceptors/genetics , Dopamine , Dopaminergic Neurons/metabolism , Endocytosis , Female , Gene Expression , Gene Knock-In Techniques , Genes, Reporter , Male , Mice , Mice, Transgenic , Protein Transport , Receptors, Dopamine D2/genetics , Recombinant Fusion Proteins , Signal Transduction
9.
Environ Sci Technol ; 51(11): 5962-5968, 2017 Jun 06.
Article in English | MEDLINE | ID: mdl-28502163

ABSTRACT

Following the Deepwater Horizon (DWH) event in 2010, there were several lines of evidence indicating the presence of marine oil snow sedimentation and flocculent accumulation (MOSSFA). A significant amount of marine oil snow formed in the water column of the northern Gulf of Mexico (nGoM), settled rapidly, and ultimately accumulated in the sediments of the nGoM. This study utilized a commonly used radioisotope tracer (excess 210Pb, 210Pbxs) from 32 sediment cores collected from 2010 to 2013 to characterize the spatial extent of MOSSFA on the seafloor. Relative to pre-DWH conditions, an increase in 210Pbxs flux occurred in two distinct regions: (1) in the western portion of the study area on an east-northeast to west-southwest axis, stretching 230 km southwest and 140 km northeast of the DWH wellhead, and (2) in the eastern portion of the study area on a 70 km northeast to southwest axis near the DeSoto Canyon. The total sedimentary spatial extent of MOSSFA, as calculated by increased 210Pbxs flux after 2010, ranged from 12 805 to 35 425 km2. 210Pbxs flux provides a valuable tool for documenting the spatial extent of MOSSFA following DWH and will continue to aid in the determination of advective transport and ultimate depocenters of MOSSFA material.


Subject(s)
Geologic Sediments , Petroleum Pollution , Water Pollutants, Chemical , Gulf of Mexico , Lead
11.
Elife ; 42015 Aug 26.
Article in English | MEDLINE | ID: mdl-26308580

ABSTRACT

D2 autoreceptors regulate dopamine release throughout the brain. Two isoforms of the D2 receptor, D2S and D2L, are expressed in midbrain dopamine neurons. Differential roles of these isoforms as autoreceptors are poorly understood. By virally expressing the isoforms in dopamine neurons of D2 receptor knockout mice, this study assessed the calcium-dependence and drug-induced plasticity of D2S and D2L receptor-dependent G protein-coupled inwardly rectifying potassium (GIRK) currents. The results reveal that D2S, but not D2L receptors, exhibited calcium-dependent desensitization similar to that exhibited by endogenous autoreceptors. Two pathways of calcium signaling that regulated D2 autoreceptor-dependent GIRK signaling were identified, which distinctly affected desensitization and the magnitude of D2S and D2L receptor-dependent GIRK currents. Previous in vivo cocaine exposure removed calcium-dependent D2 autoreceptor desensitization in wild type, but not D2S-only mice. Thus, expression of D2S as the exclusive autoreceptor was insufficient for cocaine-induced plasticity, implying a functional role for the co-expression of D2S and D2L autoreceptors.


Subject(s)
Autoreceptors/metabolism , Calcium/metabolism , G Protein-Coupled Inwardly-Rectifying Potassium Channels/metabolism , Receptors, Dopamine D2/metabolism , Signal Transduction , Animals , Cocaine/metabolism , Mice, Knockout , Protein Isoforms/metabolism
12.
Oncogene ; 34(12): 1510-9, 2015 Mar 19.
Article in English | MEDLINE | ID: mdl-24727895

ABSTRACT

Interleukin (IL)-6 family cytokines signal exclusively via the gp130 coreceptor, and are implicated in smoking-associated lung cancer, the most lethal cancer worldwide. However, the role of gp130 signalling pathways in transducing the carcinogenic effects of tobacco-related compounds is ill-defined. Here, we report that lung tumourigenesis induced by the potent tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (Nicotine-derived Nitrosamine Ketone; NNK) is suppressed in gp130(F/F) knock-in mice characterized by the contrasting gp130-dependant hypoactivation of extracellular signal-regulated kinase mitogen-activated protein kinase (ERK MAPK) and phosphatidylinositol 3-kinase/Akt, and hyperactivation of signal transducer and activator of transcription (STAT)3 signalling cascades. Specifically, in response to NNK, the absolute number and size of lung lesions in gp130(F/F) mice were significantly reduced compared with gp130(+/+) littermate controls, and associated with lower cellular proliferation without any alteration to the level of apoptosis in gp130(F/F) lung tumours. At the molecular level, reduced activation of ERK MAPK, but not Akt, was observed in lung tumours of gp130(F/F) mice, and corresponded with impaired expression of several tumour suppressor genes (for example, Trp53, Tsc2). Notably, STAT3 was not activated in the lungs of gp130(+/+) mice by NNK, and genetic normalization of STAT3 activation in gp130(F/F):Stat3(-/+) mice had no effect on NNK-induced tumourigenesis. The expression of tumour suppressor genes was reduced in tumours from current versus never-smoking lung cancer patients, and in vitro pharmacological inhibition of ERK MAPK signalling in human lung cancer cells abrogated NNK-induced downmodulation of tumour suppressor gene expression. Among IL-6 cytokine family members, IL-6 gene expression was specifically upregulated by NNK in vitro and in vivo, and inversely correlated with tumour suppressor gene expression. Collectively, our data reveal that a key molecular mechanism by which NNK promotes tumour cell proliferation during tobacco carcinogen-induced lung carcinogenesis is via upregulation of IL-6 and the preferential usage of gp130-dependant ERK MAPK signalling to downmodulate tumour suppressor gene expression.


Subject(s)
Carcinogens/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Lung Neoplasms/pathology , MAP Kinase Signaling System , Nitrosamines/adverse effects , Animals , Carcinoma, Non-Small-Cell Lung/chemically induced , Carcinoma, Non-Small-Cell Lung/metabolism , Cell Line , Cell Proliferation , Cytokine Receptor gp130/genetics , Cytokine Receptor gp130/metabolism , Female , Gene Expression Regulation, Neoplastic , Humans , Interleukin-6/metabolism , Lung Neoplasms/chemically induced , Lung Neoplasms/metabolism , MAP Kinase Signaling System/drug effects , Male , Mice , Nitrosamines/metabolism
13.
Diagn Microbiol Infect Dis ; 80(1): 79-82, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24958641

ABSTRACT

Extranasal sites are common reservoirs of Staphylococcus aureus colonization and may be relevant for methicillin-resistant S. aureus (MRSA) screening and infection control strategies. The objective here was to determine whether inguinal specimens could also be screened using Xpert SA Nasal Complete assay for MRSA. Results were compared to broth enrichment culture. Among 162 consented adults seeking care in the emergency department for cutaneous abscesses, inguinal specimens were found positive for MRSA more often than nares specimens, 24% and 26% by PCR or culture, respectively, compared to 19% each by PCR or culture. Overall, 6% of adults colonized with MRSA would have been missed by nares screening alone. Compared to culture, Xpert SA Nasal Complete assay demonstrated sensitivity and specificity of 89% and 97%, respectively, for detecting nares and/or inguinal MRSA colonization. In conclusion, inguinal specimens were a more common reservoir for MRSA than nares specimens in this population of patients.


Subject(s)
Abscess/diagnosis , Bacteriological Techniques/methods , Carrier State/diagnosis , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Staphylococcal Infections/diagnosis , Abscess/microbiology , Adolescent , Adult , Aged , Aged, 80 and over , Carrier State/microbiology , Female , Humans , Male , Middle Aged , Nasal Cavity/microbiology , Prospective Studies , Sensitivity and Specificity , Staphylococcal Infections/microbiology , Young Adult
14.
Neuron ; 82(6): 1346-56, 2014 Jun 18.
Article in English | MEDLINE | ID: mdl-24857021

ABSTRACT

GABA release from interneurons in VTA, projections from the nucleus accumbens (NAc), and rostromedial tegmental nucleus (RMTg) was selectively activated in rat brain slices. The inhibition induced by µ-opioid agonists was pathway dependent. Morphine induced a 46% inhibition of IPSCs evoked from the RMTg, 18% from NAc, and IPSCs evoked from VTA interneurons were almost insensitive (11% inhibition). In vivo morphine treatment resulted in tolerance to the inhibition of RMTg, but not local interneurons or NAc, inputs. One common sign of opioid withdrawal is an increase in adenosine-dependent inhibition. IPSCs evoked from the NAc were potently inhibited by activation of presynaptic adenosine receptors, whereas IPSCs evoked from RMTg were not changed. Blockade of adenosine receptors selectively increased IPSCs evoked from the NAc during morphine withdrawal. Thus, the acute action of opioids, the development of tolerance, and the expression of withdrawal are mediated by separate GABA afferents to dopamine neurons.


Subject(s)
Analgesics, Opioid/administration & dosage , Dopaminergic Neurons/physiology , Drug Tolerance/physiology , Substance Withdrawal Syndrome/metabolism , gamma-Aminobutyric Acid/physiology , Afferent Pathways/drug effects , Afferent Pathways/physiology , Animals , Dopaminergic Neurons/drug effects , Female , Infusions, Intraventricular , Male , Organ Culture Techniques , Rats , Rats, Sprague-Dawley
15.
Commun Integr Biol ; 6(2): e23501, 2013 Mar 01.
Article in English | MEDLINE | ID: mdl-23750304

ABSTRACT

Alcohol addiction is a disease that includes a diverse set of phenotypes. Functional alcohol tolerance is an adaptation to the effects of alcohol that restores neuronal homeostatic balance while the drug is present. When the drug is suddenly withheld, these adaptations unbalance the nervous system and are thought to be the origin of some withdrawal symptoms. Withdrawal symptoms, which can be a motivating factor for alcoholics to relapse, are taken as evidence of physiological ethanol dependence. Both tolerance and withdrawal symptoms are diagnostic criteria for alcoholism. Recent studies have demonstrated that the larvae of Drosophila show conserved alcohol tolerance and withdrawal phenotypes indicating that Drosophila genetics can now be used in studying this endophenotype of alcohol addiction.

16.
Curr Opin Neurobiol ; 23(4): 529-34, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23462335

ABSTRACT

Alcohol addiction is a complex, unique human disease. Breaking addiction down into contributing endophenotypes enables its study in a variety of model systems. The Drosophila model system has been most often used to study alcohol sensitivity, tolerance, and physiological dependence. However, none of these endophenotypes can account for the near-permanent quality of the addicted state. It has been recently discussed that addictive drugs may hijack the learning-and-memory machinery to produce persistent behavioral changes. Learning and memory is amenable to experimental study, and provides us with a window into how alcohol affects higher-order mental functions that are likely to contribute compulsive drug use. Here, we review the Drosophila literature that links alcohol-related behaviors to learning and memory.


Subject(s)
Alcoholism , Disease Models, Animal , Learning , Alcoholism/genetics , Alcoholism/pathology , Alcoholism/physiopathology , Animals , Brain/drug effects , Central Nervous System Depressants , Drosophila , Ethanol/pharmacology , Humans , Reward
17.
Curr Biol ; 22(24): 2338-41, 2012 Dec 18.
Article in English | MEDLINE | ID: mdl-23200990

ABSTRACT

Physiological alcohol dependence is a key adaptation to chronic ethanol consumption that underlies withdrawal symptoms, is thought to directly contribute to alcohol addiction behaviors, and is associated with cognitive problems such as deficits in learning and memory. Based on the idea that an ethanol-adapted (dependent) animal will perform better in a learning assay than an animal experiencing ethanol withdrawal will, we have used a learning paradigm to detect physiological ethanol dependence in Drosophila. Moderate ethanol consumption initially degrades the capacity of larvae to learn, but they eventually adapt and are able to learn as well as ethanol-naive animals. However, withholding ethanol from ethanol-adapted larvae impairs learning. Ethanol reinstatement restores the capacity to learn, thus demonstrating cognitive dependence on ethanol. The larval nervous system also shows ethanol-withdrawal hyperexcitability. Larvae reach ethanol concentrations equivalent to 0.05 to 0.08 blood-alcohol concentration-levels that would be mildly intoxicating in humans. These ethanol-induced changes in learning are not the product of sensory deficits or state-dependent learning. This is the first demonstration of cognitive ethanol dependence in an invertebrate genetic model system.


Subject(s)
Adaptation, Physiological , Cognition/drug effects , Ethanol/adverse effects , Neurons/physiology , Substance Withdrawal Syndrome/physiopathology , Animals , Drosophila
18.
PLoS One ; 7(5): e37394, 2012.
Article in English | MEDLINE | ID: mdl-22624024

ABSTRACT

Drosophila melanogaster has proven to be a useful model system for the genetic analysis of ethanol-associated behaviors. However, past studies have focused on the response of the adult fly to large, and often sedating, doses of ethanol. The pharmacological effects of low and moderate quantities of ethanol have remained understudied. In this study, we tested the acute effects of low doses of ethanol (∼7 mM internal concentration) on Drosophila larvae. While ethanol did not affect locomotion or the response to an odorant, we observed that ethanol impaired associative olfactory learning when the heat shock unconditioned stimulus (US) intensity was low but not when the heat shock US intensity was high. We determined that the reduction in learning at low US intensity was not a result of ethanol anesthesia since ethanol-treated larvae responded to the heat shock in the same manner as untreated animals. Instead, low doses of ethanol likely impair the neuronal plasticity that underlies olfactory associative learning. This impairment in learning was reversible indicating that exposure to low doses of ethanol does not leave any long lasting behavioral or physiological effects.


Subject(s)
Ethanol/toxicity , Learning/drug effects , Models, Animal , Motor Activity/drug effects , Smell/drug effects , Animals , Chromatography, Gas , Dose-Response Relationship, Drug , Drosophila melanogaster , Larva/drug effects , Larva/physiology , Learning/physiology , Motor Activity/physiology , Smell/physiology , Temperature
19.
Behav Genet ; 42(1): 151-61, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21833772

ABSTRACT

Adult Drosophila melanogaster has long been a popular model for learning and memory studies. Now the larval stage of the fruit fly is also being used in an increasing number of classical conditioning studies. In this study, we employed heat shock as a novel negative reinforcement for larvae and obtained high learning scores following just one training trial. We demonstrated heat-shock conditioning in both reciprocal and non-reciprocal paradigms and observed that the time window of association for the odor and heat shock reinforcement is on the order of a few minutes. This is slightly wider than the time window for electroshock conditioning reported in previous studies, possibly due to lingering effects of the high temperature. To test the utility of this simplified assay for the identification of new mutations that disrupt learning, we examined flies carrying mutations in the dnc gene. While the sensitivity to heat shock, as tested by writhing, was similar for wild type and dnc homozygotes, dnc mutations strongly diminished learning. We confirmed that the learning defect in dnc flies was indeed due to mutation in the dnc gene using non-complementation analysis. Given that heat shock has not been employed as a reinforcement for larvae in the past, we explored learning as a function of heat shock intensity and found that optimal learning occurred around 41 °C, with higher and lower temperatures both resulting in lower learning scores. In summary, we have developed a very simple, robust paradigm of learning in fruit fly larvae using heat shock reinforcement.


Subject(s)
Drosophila melanogaster/embryology , Genetics, Behavioral/methods , Heat-Shock Response/genetics , Smell/genetics , Animals , Conditioning, Psychological , Genetic Complementation Test , Hot Temperature , Larva/genetics , Learning , Memory , Models, Genetic , Mutation , Odorants , Reinforcement, Psychology
20.
J Appl Physiol (1985) ; 109(6): 1573-81, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20651217

ABSTRACT

We examined the effects of exercise intensity and training on rates of lipolysis, plasma free fatty acid (FFA) appearance (R(a)), disappearance (R(d)), reesterification (R(s)), and oxidation (R(oxP)) in postmenopausal (PM) women. Ten sedentary but healthy women (55 ± 0.6 yr) completed 12 wk of supervised endurance exercise training on a cycle ergometer [5 days/wk, 1 h/day, 65% peak oxygen consumption (Vo(2peak))]. Flux rates were determined by continuous infusion of [1-(13)C]palmitate and [1,1,2,3,3-(2)H(5)]glycerol during 90 min of rest and 60 min of cycle ergometer exercise during one pretraining exercise trial [65% Vo(2peak) (PRE)] and two posttraining exercise trials [at power outputs that elicited 65% pretraining Vo(2peak) (absolute training; ABT) and 65% posttraining Vo(2peak) (relative training; RLT)]. Initial body weights (68.2 ± 4.5 kg) were maintained over the course of study. Training increased Vo(2peak) by 16.3 ± 3.9% (P < 0.05) (Zarins ZA, Wallis GA, Faghihnia N, Johnson ML, Fattor JA, Horning MA and Brooks GA. Metabolism 58: 9: 1338-1346, 2009). Glycerol R(a) and R(d) were elevated in the RLT trial (P < 0.05), but not the ABT trial after training. Rates of plasma FFA R(a), R(d), and R(oxP) were elevated during the ABT compared with PRE trial (P < 0.05). FFA R(s) accounted for most (50-70%) of R(d) during exercise; training reduced FFA R(s) during ABT, but not RLT compared with PRE. We conclude that, despite the large age-related decrease in metabolic scope in PM women, endurance training increases the capacities for FFA mobilization and oxidation during exercises of a given power output. However, after menopause, total lipid oxidation capacity remains low, with reesterification accounting for most of FFA R(d).


Subject(s)
Aging/metabolism , Energy Metabolism , Fatty Acids, Nonesterified/metabolism , Lipolysis , Physical Endurance , Postmenopause , Bicycling , Body Weight , Carbon Isotopes , Esterification , Fatty Acids, Nonesterified/administration & dosage , Fatty Acids, Nonesterified/blood , Female , Glycerol/administration & dosage , Glycerol/metabolism , Humans , Infusions, Intravenous , Kinetics , Middle Aged , Oxidation-Reduction , Oxygen Consumption , Palmitic Acid/administration & dosage , Palmitic Acid/metabolism
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