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1.
Hous Policy Debate ; 33(2): 453-486, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37347089

RESUMO

Although non-experimental studies find robust neighborhood effects on adults, such findings have been challenged by results from the Moving to Opportunity (MTO) residential mobility experiment. Using a within-study comparison design, this paper compares experimental and non-experimental estimates from MTO and a parallel analysis of the Panel Study of Income Dynamics (PSID). Striking similarities were found between non-experimental estimates based on MTO and PSID. No clear evidence was found that different estimates are related to duration of adult exposure to disadvantaged neighborhoods, non-linear effects of neighborhood conditions, magnitude of the change in neighborhood context, frequency of moves, treatment effect heterogeneity, or measurement, although uncertainty bands around our estimates were sometimes large. One other possibility is that MTO-induced moves might have been unusually disruptive, but results are inconsistent for that hypothesis. Taken together, the findings suggest that selection bias might account for evidence of neighborhood effects on adult economic outcomes in non-experimental studies.

2.
Am J Epidemiol ; 191(8): 1444-1452, 2022 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-34089046

RESUMO

Antipoverty policies have the potential to improve mental health. We conducted a randomized trial (Paycheck Plus Health Study Randomized Controlled Trial, New York, New York) to investigate whether a 4-fold increase in the Earned Income Tax Credit for low-income Americans without dependent children would reduce psychological distress relative to the current federal credit. Between 2013 and 2014, a total of 5,968 participants were recruited; 2,997 were randomly assigned to the treatment group and 2,971 were assigned to the control group. Survey data were collected 32 months postrandomization (n = 4,749). Eligibility for the program increased employment by 1.9 percentage points and after-bonus earnings by 6% ($635/year), on average, over the 3 years of the study. Treatment was associated with a marginally statistically significant decline in psychological distress, as measured by the 6-item Kessler Psychological Distress Scale, relative to the control group (score change = -0.30 points, 95% confidence interval (CI): -0.63, 0.03; P = 0.072). Women in the treated group experienced a half-point reduction in psychological distress (score change = -0.55 points, 95% CI: -0.97, -0.13; P = 0.032), and noncustodial parents had a 1.36-point reduction (95% CI: -2.24, -0.49; P = 0.011). Expansion of a large antipoverty program to individuals without dependent children reduced psychological distress for women and noncustodial parents-the groups that benefitted the most in terms of increased after-bonus earnings.


Assuntos
Imposto de Renda , Angústia Psicológica , Criança , Feminino , Humanos , Renda , Pobreza , Impostos , Estados Unidos
3.
Health Aff (Millwood) ; 39(7): 1149-1156, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32634360

RESUMO

Antipoverty policies may hold promise as tools to improve health and reduce mortality rates among low-income Americans. We examined the health effects of the New York City Paycheck Plus randomized controlled trial. Paycheck Plus tests the impact of a potential fourfold increase in the Earned Income Tax Credit for low-income Americans without dependent children. Starting in 2015, Paycheck Plus offered 5,968 study participants a credit of up to $2,000 at tax time (treatment) or the standard credit of about $500 (control). Health-related quality of life and other outcomes for a representative subset of these participants (n = 3,289) were compared to those of a control group thirty-two months after randomization. The intervention had a modest positive effect on employment and earnings, particularly among women. It had no effect on health-related quality of life for the overall sample, but women realized significant improvements.


Assuntos
Imposto de Renda , Qualidade de Vida , Criança , Feminino , Humanos , Renda , Cidade de Nova Iorque , Impostos , Estados Unidos
4.
Science ; 364(6438): 334, 2019 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-31023914
5.
Science ; 356(6336): 382-383, 2017 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-28438989
7.
Am Econ Rev ; 106(4): 855-902, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29546974

RESUMO

The Moving to Opportunity (MTO) experiment offered randomly selected families housing vouchers to move from high-poverty housing projects to lower-poverty neighborhoods. We analyze MTO's impacts on children's long-term outcomes using tax data. We find that moving to a lower-poverty neighborhood when young (before age 13) increases college attendance and earnings and reduces single parenthood rates. Moving as an adolescent has slightly negative impacts, perhaps because of disruption effects. The decline in the gains from moving with the age when children move suggests that the duration of exposure to better environments during childhood is an important determinant of children's long-term outcomes.


Assuntos
Habitação , Renda , Pobreza , Características de Residência , Determinantes Sociais da Saúde , Mobilidade Social , Adolescente , Coeficiente de Natalidade , Criança , Pré-Escolar , Escolaridade , Feminino , Humanos , Ilegitimidade , Casamento , Gravidez , Determinantes Sociais da Saúde/economia , Determinantes Sociais da Saúde/estatística & dados numéricos , Estados Unidos , Adulto Jovem
8.
Neurology ; 85(24): 2090-7, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26561294

RESUMO

OBJECTIVE: The role of physician experience and patient volumes on the outcome of surgical or endovascular procedures has been well-studied but there are limited data on how these factors affect the outcome of medical therapy. METHODS: In the stenting and medical cohorts of the Stenting and Aggressive Medical Management for the Prevention of Recurrent Ischemic Stroke (SAMMPRIS) trial, we compared Kaplan-Meier (K-M) curves for the primary endpoint (any stroke or death within 30 days of enrollment or ischemic stroke in the territory beyond 30 days) using the log-rank test and the percentages of patients achieving target levels for primary and secondary risk factors during the study using Fisher exact test between patients at high-enrolling (≥12 patients) vs low-enrolling (<12 patients) sites. RESULTS: In the stenting group, the K-M curves for the primary endpoint were similar at high-enrolling sites and low-enrolling sites (p = 0.93) with rates of 13.5% vs 14.7% at 30 days and 19.0% vs 20.6% at 2 years. In the medical group, the K-M curves differed between high-enrolling sites and low-enrolling sites (p = 0.0005) with rates of 1.8% vs 9.8% at 30 days and 7.3% vs 20.9% at 2 years. The percentages of patients who achieved targets for low-density lipoprotein cholesterol and systolic blood pressure at high- vs low-enrolling sites in both treatment groups combined were 64% vs 49% (p = 0.003) and 70% vs 59% (p = 0.026), respectively. CONCLUSIONS: High-enrolling sites in SAMMPRIS achieved better control of primary risk factors and much lower rates of the primary endpoint than low-enrolling sites in the medical group, suggesting that experience with medical management is an important determinant of patient outcome.


Assuntos
Isquemia Encefálica/epidemiologia , Isquemia Encefálica/cirurgia , Seleção de Pacientes , Stents , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/prevenção & controle , Isquemia Encefálica/diagnóstico , Feminino , Seguimentos , Humanos , Masculino , Fatores de Risco , Acidente Vascular Cerebral/diagnóstico , Resultado do Tratamento
9.
Proc Natl Acad Sci U S A ; 112(38): 11817-22, 2015 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-26351663

RESUMO

African-American Vernacular English (AAVE) is systematic, rooted in history, and important as an identity marker and expressive resource for its speakers. In these respects, it resembles other vernacular or nonstandard varieties, like Cockney or Appalachian English. But like them, AAVE can trigger discrimination in the workplace, housing market, and schools. Understanding what shapes the relative use of AAVE vs. Standard American English (SAE) is important for policy and scientific reasons. This work presents, to our knowledge, the first experimental estimates of the effects of moving into lower-poverty neighborhoods on AAVE use. We use data on non-Hispanic African-American youth (n = 629) from a large-scale, randomized residential mobility experiment called Moving to Opportunity (MTO), which enrolled a sample of mostly minority families originally living in distressed public housing. Audio recordings of the youth were transcribed and coded for the use of five grammatical and five phonological AAVE features to construct a measure of the proportion of possible instances, or tokens, in which speakers use AAVE rather than SAE speech features. Random assignment to receive a housing voucher to move into a lower-poverty area (the intention-to-treat effect) led youth to live in neighborhoods (census tracts) with an 11 percentage point lower poverty rate on average over the next 10-15 y and reduced the share of AAVE tokens by ∼3 percentage points compared with the MTO control group youth. The MTO effect on AAVE use equals approximately half of the difference in AAVE frequency observed between youth whose parents have a high school diploma and those whose parents do not.


Assuntos
Negro ou Afro-Americano , Idioma , Características de Residência , Adolescente , Criança , Feminino , Humanos , Masculino
10.
JAMA ; 311(9): 937-48, 2014 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-24595778

RESUMO

IMPORTANCE: Youth in high-poverty neighborhoods have high rates of emotional problems. Understanding neighborhood influences on mental health is crucial for designing neighborhood-level interventions. OBJECTIVE: To perform an exploratory analysis of associations between housing mobility interventions for children in high-poverty neighborhoods and subsequent mental disorders during adolescence. DESIGN, SETTING, AND PARTICIPANTS: The Moving to Opportunity Demonstration from 1994 to 1998 randomized 4604 volunteer public housing families with 3689 children in high-poverty neighborhoods into 1 of 2 housing mobility intervention groups (a low-poverty voucher group vs a traditional voucher group) or a control group. The low-poverty voucher group (n=1430) received vouchers to move to low-poverty neighborhoods with enhanced mobility counseling. The traditional voucher group (n=1081) received geographically unrestricted vouchers. Controls (n=1178) received no intervention. Follow-up evaluation was performed 10 to 15 years later (June 2008-April 2010) with participants aged 13 to 19 years (0-8 years at randomization). Response rates were 86.9% to 92.9%. MAIN OUTCOMES AND MEASURES: Presence of mental disorders from the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) within the past 12 months, including major depressive disorder, panic disorder, posttraumatic stress disorder (PTSD), oppositional-defiant disorder, intermittent explosive disorder, and conduct disorder, as assessed post hoc with a validated diagnostic interview. RESULTS: Of the 3689 adolescents randomized, 2872 were interviewed (1407 boys and 1465 girls). Compared with the control group, boys in the low-poverty voucher group had significantly increased rates of major depression (7.1% vs 3.5%; odds ratio (OR), 2.2 [95% CI, 1.2-3.9]), PTSD (6.2% vs 1.9%; OR, 3.4 [95% CI, 1.6-7.4]), and conduct disorder (6.4% vs 2.1%; OR, 3.1 [95% CI, 1.7-5.8]). Boys in the traditional voucher group had increased rates of PTSD compared with the control group (4.9% vs 1.9%, OR, 2.7 [95% CI, 1.2-5.8]). However, compared with the control group, girls in the traditional voucher group had decreased rates of major depression (6.5% vs 10.9%; OR, 0.6 [95% CI, 0.3-0.9]) and conduct disorder (0.3% vs 2.9%; OR, 0.1 [95% CI, 0.0-0.4]). CONCLUSIONS AND RELEVANCE: Interventions to encourage moving out of high-poverty neighborhoods were associated with increased rates of depression, PTSD, and conduct disorder among boys and reduced rates of depression and conduct disorder among girls. Better understanding of interactions among individual, family, and neighborhood risk factors is needed to guide future public housing policy changes.


Assuntos
Transtornos Mentais/epidemiologia , Pobreza , Habitação Popular , Características de Residência , Adolescente , Criança , Pré-Escolar , Aconselhamento , Feminino , Financiamento Pessoal , Seguimentos , Humanos , Masculino , Política Pública , Risco , Fatores Sexuais , Adulto Jovem
11.
J Exp Criminol ; 9(4)2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24348277

RESUMO

OBJECTIVES: Using data from a randomized experiment, to examine whether moving youth out of areas of concentrated poverty, where a disproportionate amount of crime occurs, prevents involvement in crime. METHODS: We draw on new administrative data from the U.S. Department of Housing and Urban Development's Moving to Opportunity (MTO) experiment. MTO families were randomized into an experimental group offered a housing voucher that could only be used to move to a low-poverty neighborhood, a Section 8 housing group offered a standard housing voucher, and a control group. This paper focuses on MTO youth ages 15-25 in 2001 (n = 4,643) and analyzes intention to treat effects on neighborhood characteristics and criminal behavior (number of violent- and property-crime arrests) through 10 years after randomization. RESULTS: We find the offer of a housing voucher generates large improvements in neighborhood conditions that attenuate over time and initially generates substantial reductions in violent-crime arrests and sizable increases in property-crime arrests for experimental group males. The crime effects attenuate over time along with differences in neighborhood conditions. CONCLUSIONS: Our findings suggest that criminal behavior is more strongly related to current neighborhood conditions (situational neighborhood effects) than to past neighborhood conditions (developmental neighborhood effects). The MTO design makes it difficult to determine which specific neighborhood characteristics are most important for criminal behavior. Our administrative data analyses could be affected by differences across areas in the likelihood that a crime results in an arrest.

12.
Future Child ; 23(1): 137-63, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-25522649

RESUMO

For-profit, or proprietary, colleges are the fastest-growing postsecondary schools in the nation, enrolling a disproportionately high share of disadvantaged and minority students and those ill-prepared for college. Because these schools, many of them big national chains, derive most of their revenue from taxpayer-funded student financial aid, they are of interest to policy makers not only for the role they play in the higher education spectrum but also for the value they provide their students. In this article, David Deming, Claudia Goldin, and Lawrence Katz look at the students who attend for-profits, the reasons they choose these schools, and student outcomes on a number of broad measures and draw several conclusions. First, the authors write, the evidence shows that public community colleges may provide an equal or better education at lower cost than for-profits. But budget pressures mean that community colleges and other nonselective public institutions may not be able to meet the demand for higher education. Some students unable to get into desired courses and programs at public institutions may face only two alternatives: attendance at a for-profit or no postsecondary education at all. Second, for-profits appear to be at their best with well-defined programs of short duration that prepare students for a specific occupation. But for-profit completion rates, default rates, and labor market outcomes for students seeking associate's or higher degrees compare unfavorably with those of public postsecondary institutions. In principle, taxpayer investment in student aid should be accompanied by scrutiny concerning whether students complete their course of study and subsequently earn enough to justify the investment and pay back their student loans. Designing appropriate regulations to help students navigate the market for higher education has proven to be a challenge because of the great variation in student goals and types of programs. Ensuring that potential students have complete and objective information about the costs and expected benefits of for-profit programs could improve postsecondary education opportunities for disadvantaged students and counter aggressive and potentially misleading recruitment practices at for-profit colleges, the authors write.


Assuntos
Educação/economia , Escolaridade , Financiamento Governamental/economia , Grupos Minoritários/educação , Privatização/economia , Instituições Acadêmicas/economia , Apoio ao Desenvolvimento de Recursos Humanos/economia , Populações Vulneráveis , Adolescente , Adulto , Escolha da Profissão , Análise Custo-Benefício/economia , Avaliação Educacional , Humanos , Estados Unidos , Adulto Jovem
13.
Science ; 337(6101): 1505-10, 2012 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-22997331

RESUMO

Nearly 9 million Americans live in extreme-poverty neighborhoods, places that also tend to be racially segregated and dangerous. Yet, the effects on the well-being of residents of moving out of such communities into less distressed areas remain uncertain. Using data from Moving to Opportunity, a unique randomized housing mobility experiment, we found that moving from a high-poverty to lower-poverty neighborhood leads to long-term (10- to 15-year) improvements in adult physical and mental health and subjective well-being, despite not affecting economic self-sufficiency. A 1-standard deviation decline in neighborhood poverty (13 percentage points) increases subjective well-being by an amount equal to the gap in subjective well-being between people whose annual incomes differ by $13,000--a large amount given that the average control group income is $20,000. Subjective well-being is more strongly affected by changes in neighborhood economic disadvantage than racial segregation, which is important because racial segregation has been declining since 1970, but income segregation has been increasing.


Assuntos
Felicidade , Habitação , Saúde Mental , Satisfação Pessoal , Pobreza , Qualidade de Vida , Características de Residência , Adulto , Humanos , Renda , Condições Sociais , Estados Unidos , United States Government Agencies
14.
N Engl J Med ; 365(16): 1509-19, 2011 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-22010917

RESUMO

BACKGROUND: The question of whether neighborhood environment contributes directly to the development of obesity and diabetes remains unresolved. The study reported on here uses data from a social experiment to assess the association of randomly assigned variation in neighborhood conditions with obesity and diabetes. METHODS: From 1994 through 1998, the Department of Housing and Urban Development (HUD) randomly assigned 4498 women with children living in public housing in high-poverty urban census tracts (in which ≥40% of residents had incomes below the federal poverty threshold) to one of three groups: 1788 were assigned to receive housing vouchers, which were redeemable only if they moved to a low-poverty census tract (where <10% of residents were poor), and counseling on moving; 1312 were assigned to receive unrestricted, traditional vouchers, with no special counseling on moving; and 1398 were assigned to a control group that was offered neither of these opportunities. From 2008 through 2010, as part of a long-term follow-up survey, we measured data indicating health outcomes, including height, weight, and level of glycated hemoglobin (HbA(1c)). RESULTS: As part of our long-term survey, we obtained data on body-mass index (BMI, the weight in kilograms divided by the square of the height in meters) for 84.2% of participants and data on glycated hemoglobin level for 71.3% of participants. Response rates were similar across randomized groups. The prevalences of a BMI of 35 or more, a BMI of 40 or more, and a glycated hemoglobin level of 6.5% or more were lower in the group receiving the low-poverty vouchers than in the control group, with an absolute difference of 4.61 percentage points (95% confidence interval [CI], -8.54 to -0.69), 3.38 percentage points (95% CI, -6.39 to -0.36), and 4.31 percentage points (95% CI, -7.82 to -0.80), respectively. The differences between the group receiving traditional vouchers and the control group were not significant. CONCLUSIONS: The opportunity to move from a neighborhood with a high level of poverty to one with a lower level of poverty was associated with modest but potentially important reductions in the prevalence of extreme obesity and diabetes. The mechanisms underlying these associations remain unclear but warrant further investigation, given their potential to guide the design of community-level interventions intended to improve health. (Funded by HUD and others.).


Assuntos
Diabetes Mellitus/epidemiologia , Obesidade/epidemiologia , Características de Residência , Condições Sociais , Adulto , Diabetes Mellitus/economia , Feminino , Humanos , Pessoa de Meia-Idade , Obesidade/economia , Áreas de Pobreza
15.
J Neurosci ; 28(42): 10711-9, 2008 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-18923046

RESUMO

For many mammals, individual recognition of conspecifics relies on olfactory cues. Certain individual recognition memories are thought to be stored when conspecific odor cues coincide with surges of noradrenaline (NA) triggered by intensely arousing social events. Such familiar stimuli elicit reduced behavioral responses, a change likely related to NA-dependent plasticity in the olfactory bulb (OB). In addition to its role in these ethological memories, NA signaling in the OB appears to be relevant for the discrimination of more arbitrary odorants as well. Nonetheless, no NA-gated mechanism of long-term plasticity in the OB has ever been directly observed in vivo. Here, we report that NA release from locus ceruleus (LC), when coupled to odor presentation, acts locally in the main OB to cause a specific long-lasting suppression of responses to paired odors. These effects were observed for both food odors and urine, an important social recognition cue. Moreover, in subsequent behavioral tests, mice exhibited habituation to paired urine stimuli, suggesting that this LC-mediated olfactory neural plasticity, induced under anesthesia, can store an individual recognition memory that is observable after recovery.


Assuntos
Habituação Psicofisiológica/fisiologia , Memória/fisiologia , Norepinefrina/metabolismo , Odorantes , Condutos Olfatórios/fisiologia , Olfato/fisiologia , Animais , Feminino , Locus Cerúleo/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Bulbo Olfatório/fisiologia
16.
Nat Methods ; 5(4): 299-302, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18327266

RESUMO

Here we describe a knock-in mouse model for Cre-loxP-based conditional expression of TRPV1 in central nervous system neurons. Expression of Cre recombinase using biolistics, lentivirus or genetic intercrosses triggered heterologous expression of TRPV1 in a cell-specific manner. Application of the TRPV1 ligand capsaicin induced strong inward currents, triggered action potentials and activated stereotyped behaviors, allowing cell type-specific chemical genetic control of neuronal activity in vitro and in vivo.


Assuntos
Comportamento Animal , Integrases , Neurônios , Recombinação Genética , Canais de Cátion TRPV/genética , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/genética , Animais , Comportamento Animal/efeitos dos fármacos , Encéfalo/metabolismo , Capsaicina/farmacologia , Marcação de Genes , Genes Reporter , Vetores Genéticos , Proteínas de Fluorescência Verde/genética , Imuno-Histoquímica , Integrases/biossíntese , Lentivirus/genética , Camundongos , Camundongos Knockout , Neurônios/enzimologia , Neurônios/metabolismo , Neurônios/fisiologia , Técnicas de Patch-Clamp , Ratos , Transfecção
17.
J Neurosci ; 27(8): 2091-101, 2007 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-17314304

RESUMO

The mammalian olfactory system recognizes an enormous variety of odorants carrying a wide range of important behavioral cues. In the main olfactory bulb (MOB), odorants are ultimately represented through the action potential activity of mitral/tufted cells (M/Ts), whose selectivity and tuning to odorant molecules are therefore fundamental determinants of MOB sensory coding. However, the sheer number and diversity of discrete olfactory stimuli has been a major barrier to comprehensively evaluating M/T selectivity. To address this issue, we assessed M/T odorant responses in anesthetized mice to a 348-odorant panel widely and systematically distributed throughout chemical space, presented both individually and in mixtures at behaviorally relevant concentrations. We found that M/T activation by odorants was markedly selective, with neurons responding robustly, sensitively, and reliably to only a highly restricted subset of stimuli. Multiple odorants activating a single neuron commonly shared clear structural similarity, but M/T tuning also frequently extended beyond obviously defined chemical categories. Cells typically responded to effective compounds presented both individually and in mixtures, although firing rates evoked by mixtures typically showed partial suppression. Response selectivity was further confirmed in awake animals by chronic recordings of M/Ts. These data indicate that individual M/Ts encode specific odorant attributes shared by only a small fraction of compounds and imply that the MOB relays the collective molecular features of an odorant stimulus through a restricted set of M/Ts, each narrowly tuned to a particular stimulus characteristic.


Assuntos
Neurônios Aferentes/fisiologia , Odorantes , Bulbo Olfatório/fisiologia , Olfato/fisiologia , Animais , Fenômenos Químicos , Química , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estrutura Molecular , Bulbo Olfatório/citologia , Limiar Sensorial
18.
J Neurosci ; 26(46): 12023-32, 2006 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-17108176

RESUMO

Individual odorants activate only a small fraction of mitral cells in the mouse main olfactory bulb (MOB). Odor mixtures are represented by a combination of activated mitral cells, forming reproducible activation maps in the olfactory bulb. However, how the activation of a cohort of narrowly tuned mitral cells by odor mixtures is read out synaptically by neurons in higher-level olfactory structures, such as the anterior olfactory nucleus (AON), is mostly unknown. In the current study, we used intracellular and extracellular recordings to examine and compare responses of AON neurons and MOB mitral cells to a panel of structurally diverse odorants presented either as mixtures or as individual components. We found that a majority of individual AON neurons could be synaptically activated by several mixtures of structurally dissimilar components and by several dissimilar components in an effective mixture. The suprathreshold response of an AON neuron to an effective mixture often exceeded the sum of its suprathreshold responses to all of the components in that mixture, indicating a nonlinear combinatorial interaction. In contrast to the broad responsiveness of AON neurons, the majority of mitral cells were activated by only one or two components in a single mixture. The broader responsiveness of AON neurons relative to mitral cells suggests that individual AON neurons synaptically integrate several functionally distinct mitral cell inputs.


Assuntos
Neurônios/fisiologia , Bulbo Olfatório/fisiologia , Condutos Olfatórios/fisiologia , Olfato/fisiologia , Transmissão Sináptica/fisiologia , Potenciais de Ação/fisiologia , Animais , Dendritos/fisiologia , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Vias Neurais/fisiologia , Neurônios/citologia , Odorantes , Bulbo Olfatório/citologia , Condutos Olfatórios/citologia , Terminações Pré-Sinápticas/fisiologia , Sinapses/fisiologia
19.
Neuron ; 50(6): 937-49, 2006 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-16772174

RESUMO

Natural odorants are complex mixtures of diverse chemical compounds. Monomolecular odorants are represented in the main olfactory bulb by distinct spatial patterns of activated glomeruli. However, it remains unclear how individual compounds contribute to population representations of natural stimuli, which appear to be unexpectedly sparse. We combined gas chromatography and intrinsic signal imaging to visualize glomerular responses to natural stimuli and their fractionated components. While whole stimuli activated up to 20 visible glomeruli, each fractionated component activated only one or few glomeruli, and most glomeruli were activated by only one component. Thus, responses to complex mixtures reflected activation by multiple components, with each contributing only a small part of the overall representation. We conclude that the population response to a complex stimulus is largely the sum of the responses to its individual components, and activation of an individual glomerulus independently signals the presence of a specific component.


Assuntos
Mapeamento Encefálico/métodos , Odorantes , Bulbo Olfatório/fisiologia , Olfato/fisiologia , Animais , Cromatografia Gasosa/métodos , Feminino , Raposas , Lynx , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Odorantes/análise , Bulbo Olfatório/química , Ratos , Sensibilidade e Especificidade
20.
Proc Natl Acad Sci U S A ; 103(6): 1912-7, 2006 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-16446451

RESUMO

As a consequence of adult neurogenesis, the olfactory bulb (OB) receives a continuous influx of newborn neurons well into adulthood. However, their rates of generation and turnover, the factors controlling their survival, and how newborn neurons intercalate into adult circuits are largely unknown. To visualize the dynamics of adult neurogenesis, we produced a line of transgenic mice expressing GFP in approximately 70% of juxtaglomerular neurons (JGNs), a population that undergoes adult neurogenesis. Using in vivo two-photon microscopy, time-lapse analysis of identified JGN cell bodies revealed a neuronal turnover rate of approximately 3% of this population per month. Although new neurons appeared and older ones disappeared, the overall number of JGNs remained constant. This approach provides a dynamic view of the actual appearance and disappearance of newborn neurons in the vertebrate central nervous system, and provides an experimental substrate for functional analysis of adult neurogenesis.


Assuntos
Sistema Justaglomerular/citologia , Neurônios/citologia , Bulbo Olfatório/citologia , Animais , Proliferação de Células , Genes Reporter/genética , Camundongos , Camundongos Transgênicos , Fenótipo
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