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1.
J Exp Biol ; 224(23)2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34796902

RESUMO

Sexual traits that promote species recognition are important drivers of reproductive isolation, especially among closely related species. Identifying neural processes that shape species differences in recognition is crucial for understanding the causal mechanisms of reproductive isolation. Temporal patterns are salient features of sexual signals that are widely used in species recognition by several taxa, including anurans. Recent advances in our understanding of temporal processing by the anuran auditory system provide an opportunity to investigate the neural basis of species-specific recognition. The anuran inferior colliculus consists of neurons that are selective for temporal features of calls. Of potential relevance are auditory neurons known as interval-counting neurons (ICNs) that are often selective for the pulse rate of conspecific advertisement calls. Here, we tested the hypothesis that ICNs mediate acoustic species recognition by exploiting the known differences in temporal selectivity in two cryptic species of gray treefrog (Hyla chrysoscelis and Hyla versicolor). We examined the extent to which the threshold number of pulses required to elicit behavioral responses from females and neural responses from ICNs was similar within each species but potentially different between the two species. In support of our hypothesis, we found that a species difference in behavioral pulse number thresholds closely matched the species difference in neural pulse number thresholds. However, this relationship held only for ICNs that exhibited band-pass tuning for conspecific pulse rates. Together, these findings suggest that differences in temporal processing of a subset of ICNs provide a mechanistic explanation for reproductive isolation between two cryptic treefrog species.


Assuntos
Colículos Inferiores , Vocalização Animal , Estimulação Acústica , Acústica , Animais , Anuros , Percepção Auditiva , Feminino
2.
Proc Natl Acad Sci U S A ; 113(13): E1927-35, 2016 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-26976602

RESUMO

Sound duration is important in acoustic communication, including speech recognition in humans. Although duration-selective auditory neurons have been found, the underlying mechanisms are unclear. To investigate these mechanisms we combined in vivo whole-cell patch recordings from midbrain neurons, extraction of excitatory and inhibitory conductances, and focal pharmacological manipulations. We show that selectivity for short-duration stimuli results from integration of short-latency, sustained inhibition with delayed, phasic excitation; active membrane properties appeared to amplify responses to effective stimuli. Blocking GABAA receptors attenuated stimulus-related inhibition, revealed suprathreshold excitation at all stimulus durations, and decreased short-pass selectivity without changing resting potentials. Blocking AMPA and NMDA receptors to attenuate excitation confirmed that inhibition tracks stimulus duration and revealed no evidence of postinhibitory rebound depolarization inherent to coincidence models of duration selectivity. These results strongly support an anticoincidence mechanism of short-pass selectivity, wherein inhibition and suprathreshold excitation show greatest temporal overlap for long duration stimuli.


Assuntos
Mesencéfalo/fisiologia , Neurônios/fisiologia , Som , Estimulação Acústica/métodos , Animais , Percepção Auditiva/fisiologia , Limiar Auditivo , Feminino , Antagonistas de Receptores de GABA-A/farmacologia , Masculino , Mesencéfalo/citologia , Modelos Biológicos , Neurônios/efeitos dos fármacos , Técnicas de Patch-Clamp , Rana pipiens , Receptores de AMPA/antagonistas & inibidores , Receptores de AMPA/fisiologia , Receptores de GABA-A/fisiologia , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Receptores de N-Metil-D-Aspartato/fisiologia , Fatores de Tempo
3.
J Exp Biol ; 221(Pt 23)2018 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-30305374

RESUMO

Although socially controlled sex transformation in fishes is well established, the underlying mechanisms are not well understood. Particularly enigmatic is behavioural transformation, in which fish can rapidly switch from exhibiting female to male-typical courtship behaviours following removal of 'supermales'. Bluehead wrasses are a model system for investigating environmental control of sex determination, particularly the social control of sex transformation. Here, we show that the onset of this behavioural transformation was delayed in females that occupied low-ranking positions in the female dominance hierarchy. We also establish that expression of male-typical courtship behaviours in competent initial-phase (IP) females is facultative and gated by the presence of terminal-phase (TP) males. Dominant females displayed reliable TP male-typical courtship behaviours within approximately 2 days of the removal of a TP male; immediately following reintroduction of the TP male, however, females reverted back to female-typical behaviours. These results demonstrate a remarkable plasticity of sexual behaviour and support a 'priming/gating' hypothesis for the control of behavioural transformation in bluehead wrasses.


Assuntos
Corte , Perciformes/fisiologia , Comportamento Sexual Animal/fisiologia , Animais , Feminino , Masculino , Processos de Determinação Sexual/fisiologia , Predomínio Social , Gravação em Vídeo
4.
AIDS Behav ; 22(1): 276-286, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28578544

RESUMO

We conducted a randomized trial comparing the effect of two different levels of motivational interviewing training on clinician communication behaviors and patient experiences. We enrolled 12 HIV clinicians who attended a one-day MI workshop focusing on behavior change counseling skills. We then randomized clinicians to receive (or not) 3-5 rounds of personalized feedback from the MI trainer. We compared outcomes before and after the interventions and between the intervention groups. We tested time-by-study arm interactions to determine if one group improved more than the other. For all analyses, we used generalized estimating equations to account for clustering of patients within clinicians, with Gaussian or negative binomial distributions as appropriate. Patients of clinicians in both intervention groups rated their visits as more MI consistent (6.86 vs. 6.65, p = 0.005) and audio-recording analysis revealed that visits were more patient-centered (1.34 vs. 0.96, p = 0.003) with a more positive patient affect (22.36 vs. 20.84, p < 0.001) after versus before the intervention, without differences between intervention arms. Several specific clinician behaviors such as empathic statements, asking patient opinions and open-ended questions improved more in the workshop+feedback versus the workshop-only intervention arm. A few specific communication behaviors increased (total and complex reflections) after versus before the intervention, without differences between intervention arms. The workshop alone was as effective as the workshop plus feedback in improving patient experiences and overall communication measures. Certain communication behaviors improved more with the more intensive intervention, but these additional benefits may not warrant the extra financial and logistical resources required.


Assuntos
Comunicação , Aconselhamento/métodos , Infecções por HIV/terapia , Entrevista Motivacional/métodos , Relações Médico-Paciente , Médicos de Atenção Primária/educação , Médicos/psicologia , Adulto , Educação Médica Continuada/métodos , Avaliação Educacional , Empatia , Feminino , Infecções por HIV/psicologia , Humanos , Intenção , Masculino , Pessoa de Meia-Idade , Avaliação de Processos e Resultados em Cuidados de Saúde , Gravação em Fita
5.
Artigo em Inglês | MEDLINE | ID: mdl-26614093

RESUMO

In recently diverged gray treefrogs (Hyla chrysoscelis and H. versicolor), advertisement calls that differ primarily in pulse shape and pulse rate act as an important premating isolation mechanism. Temporally selective neurons in the anuran inferior colliculus may contribute to selective behavioral responses to these calls. Here we present in vivo extracellular and whole-cell recordings from long-interval-selective neurons (LINs) made during presentation of pulses that varied in shape and rate. Whole-cell recordings revealed that interplay between excitation and inhibition shapes long-interval selectivity. LINs in H. versicolor showed greater selectivity for slow-rise pulses, consistent with the slow-rise pulse characteristics of their calls. The steepness of pulse-rate tuning functions, but not the distributions of best pulse rates, differed between the species in a manner that depended on whether pulses had slow or fast-rise shape. When tested with stimuli representing the temporal structure of the advertisement calls of H. chrysoscelis or H. versicolor, approximately 27 % of LINs in H. versicolor responded exclusively to the latter stimulus type. The LINs of H. chrysoscelis were less selective. Encounter calls, which are produced at similar pulse rates in both species (≈5 pulses/s), are likely to be effective stimuli for the LINs of both species.


Assuntos
Anuros/fisiologia , Percepção Auditiva/fisiologia , Colículos Inferiores/fisiologia , Neurônios/fisiologia , Comportamento Sexual Animal/fisiologia , Vocalização Animal/fisiologia , Estimulação Acústica , Animais , Vias Auditivas/fisiologia , Feminino , Masculino , Microeletrodos , Inibição Neural/fisiologia , Técnicas de Patch-Clamp , Especificidade da Espécie , Percepção do Tempo/fisiologia
6.
J Neurophysiol ; 114(5): 2804-15, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26334004

RESUMO

Information can be encoded in the temporal patterning of spikes. How the brain reads these patterns is of general importance and represents one of the greatest challenges in neuroscience. We addressed this issue in relation to temporal pattern recognition in the anuran auditory system. Many species of anurans perform mating decisions based on the temporal structure of advertisement calls. One important temporal feature is the number of sound pulses that occur with a species-specific interpulse interval. Neurons representing this pulse count have been recorded in the anuran inferior colliculus, but the mechanisms underlying their temporal selectivity are incompletely understood. Here, we construct a parsimonious model that can explain the key dynamical features of these cells with biologically plausible elements. We demonstrate that interval counting arises naturally when combining interval-selective inhibition with pulse-per-pulse excitation having both fast- and slow-conductance synapses. Interval-dependent inhibition is modeled here by a simple architecture based on known physiology of afferent nuclei. Finally, we consider simple implementations of previously proposed mechanistic explanations for these counting neurons and show that they do not account for all experimental observations. Our results demonstrate that tens of millisecond-range temporal selectivities can arise from simple connectivity motifs of inhibitory neurons, without recourse to internal clocks, spike-frequency adaptation, or appreciable short-term plasticity.


Assuntos
Potenciais de Ação , Percepção Auditiva/fisiologia , Colículos Inferiores/fisiologia , Modelos Neurológicos , Inibição Neural , Neurônios/fisiologia , Estimulação Acústica , Animais , Anuros , Vias Auditivas/fisiologia , Simulação por Computador , Redes Neurais de Computação , Fatores de Tempo , Vocalização Animal
7.
Artigo em Inglês | MEDLINE | ID: mdl-25764308

RESUMO

Interval-counting neurons (ICNs) respond after a threshold number of sound pulses have occurred with specific intervals; a single aberrant interval can reset the counting process. Female gray treefrogs, Hyla chrysoscelis and H. versicolor, discriminate against synthetic 'calls' possessing a single interpulse interval 2-3 three times the optimal value, suggesting that ICNs are important for call recognition. The calls of H. versicolor consist of pulses that are longer in duration, rise more slowly in amplitude and are repeated at a slower rate than those of H. chrysoscelis. Results of recordings from midbrain auditory neurons in these species include: (1) ICNs were found in both species and their temporal selectivity appeared to result from interplay between excitation and inhibition; (2) band-pass cells in H. versicolor were tuned to slower pulse rates than those in H. chrysoscelis; (3) ICNs that were selective for slow-rise pulse shape were found almost exclusively in H. versicolor, but fast-rise-selective neurons were found in both species, and (4) band-suppression ICNs in H. versicolor showed response minima at higher pulse rates than those in H. chrysoscelis. Selectivity of midbrain ICNs for pulse rise time and repetition rate thus correlate well with discriminatory abilities of these species that promote reproductive isolation.


Assuntos
Potenciais de Ação/fisiologia , Anuros/anatomia & histologia , Percepção Auditiva/fisiologia , Colículos Inferiores/citologia , Células Receptoras Sensoriais/fisiologia , Especificidade da Espécie , Vocalização Animal/fisiologia , Estimulação Acústica , Animais , Vias Auditivas , Estimulação Elétrica , Técnicas de Patch-Clamp , Som
8.
Behav Cogn Psychother ; 43(2): 129-41, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24229732

RESUMO

BACKGROUND: A recommendation in original descriptions of motivational interviewing (MI) was to "explore ambivalence". Contrasting procedures for doing so have been clarified through the evolution of MI. AIMS: This article describes two conceptually distinct methods for responding to ambivalence: decisional balance (DB) and MI's evocation of change talk, and reviews empirical evidence to recommend when each procedure is appropriate (and inappropriate) in clinical practice. METHOD: The authors summarize findings of clinical outcome research to examine how these two interventions impact the resolution of client ambivalence. RESULTS: With ambivalent people, a DB intervention tends to decrease commitment to change, whereas evocation (a key element of MI) promotes change. When a person has already made the decision to change, evocation is unnecessary and may deter change, whereas DB may further strengthen commitment. CONCLUSIONS: DB is an appropriate procedure when the clinician wishes to maintain neutrality and not favor the resolution of ambivalence in any particular direction. Evocation is appropriate when the clinician intends to help clients resolve ambivalence in the direction of change.


Assuntos
Tomada de Decisões , Entrevista Motivacional , Técnicas de Observação do Comportamento , Terapia Cognitivo-Comportamental , Emoções , Humanos , Avaliação de Resultados em Cuidados de Saúde
9.
Curr Biol ; 33(22): 4937-4949.e3, 2023 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-37898122

RESUMO

Bluehead wrasses (Thalassoma bifasciatum) follow a socially controlled mechanism of sex determination. A socially dominant initial-phase (IP) female is able to transform into a new terminal-phase (TP) male if the resident TP male is no longer present. TP males display an elaborate array of courtship behaviors, including both color changes and motor behaviors. Little is known concerning the neural circuits that control male-typical courtship behaviors. This study used glutamate iontophoresis to identify regions that may be involved in courtship. Stimulation of the following brain regions elicited diverse types of color change responses, many of which appear similar to courtship color changes: the ventral telencephalon (supracommissural nucleus of the ventral telencephalon [Vs], lateral nucleus of the ventral telencephalon [Vl], ventral nucleus of the ventral telencephalon [Vv], and dorsal nucleus of the ventral telencephalon [Vd]), parts of the preoptic area (NPOmg and NPOpc), entopeduncular nucleus, habenular nucleus, and pretectal nuclei (PSi and PSm). Stimulation of two regions in the posterior thalamus (central posterior thalamic [CP] and dorsal posterior thalamic [DP]) caused movements of the pectoral fins that are similar to courtship fluttering and vibrations. Furthermore, these responses were elicited in female IP fish, indicating that circuits for sexual behaviors typical of TP males exist in females. Immunohistochemistry results revealed regions that are more active in fish that are not courting: interpeduncular nucleus, red nucleus, and ventrolateral thalamus (VL). Taken together, we propose that the telencephalic-habenular-interpeduncular pathway plays an important role in controlling and regulating courtship behaviors in TP males; in this model, in response to telencephalic input, the habenular nucleus inhibits the interpeduncular nucleus, thereby dis-inhibiting forebrain regions and promoting the expression of courtship behaviors.


Assuntos
Corte , Perciformes , Animais , Feminino , Masculino , Telencéfalo/fisiologia , Prosencéfalo , Tálamo , Perciformes/fisiologia , Peixes
10.
Artigo em Inglês | MEDLINE | ID: mdl-20931335

RESUMO

In anurans, the temporal patterning of sound pulses is the primary information used for differentiating between spectrally similar calls. One class of midbrain neurons, referred to as 'interval-counting' cells, appears to be particularly important for discriminating among calls that differ in pulse repetition rate (PRR). These cells only respond after several pulses are presented with appropriate interpulse intervals. Here we show that the range of selectivity and sharpness of interval tuning vary considerably across neurons. Whole-cell recordings revealed that neurons showing temporally summating excitatory postsynaptic potentials (EPSPs) with little or no inhibition or activity-dependent enhancement of excitation exhibited low-pass or band-pass tuning to slow PRRs. Neurons that showed inhibition and rate-dependent enhancement of excitation, however, were band-pass or high-pass to intermediate or fast PRRs. Surprisingly, across cells, interval tuning based on membrane depolarization and spike rate measures were not significantly correlated. Neurons that lacked inhibition showed the greatest disparities between these two measures of interval tuning. Cells that showed broad membrane potential-based tuning, for example, varied considerably in their spike rate-based tuning; narrow spike rate-based tuning resulted from 'thresholding' processes, whereby only the largest depolarizations triggered spikes. The potential constraints associated with generating interval tuning in this manner are discussed.


Assuntos
Percepção Auditiva/fisiologia , Potenciais Pós-Sinápticos Excitadores/fisiologia , Mesencéfalo/citologia , Neurônios/fisiologia , Estimulação Acústica/métodos , Animais , Anuros , Vias Auditivas/fisiologia , Inibição Neural/fisiologia , Técnicas de Patch-Clamp , Psicoacústica , Tempo de Reação/fisiologia , Fatores de Tempo
11.
J Appl Lab Med ; 6(6): 1618-1622, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34142131

RESUMO

INTRODUCTION: Urine collection from incontinent individuals can be challenging. Various methods have been devised to collect the sample without catheterization. Recently the PureWick external catheter was developed to draw the sample gently away from external female genitalia. While the primary purpose of the device is to prevent moisture and maintain skin integrity, the urine that is collected may be sent for laboratory analysis. We sought to validate the use of this collection method for common urine chemistry assays and urinalysis. METHODS: Twenty pools of residual urine samples were separated into "control" and "PureWick" treated samples. The control samples were maintained at room temperature while 15 mL of urine was added to the PureWick device which was connected to a vacuum line through a collection canister. The urine collected in the canister and the controls samples were all subject to urine chemistry strip, microscopic, and automated urine chemistry analysis. Results were compared between pairs of treated and control samples. RESULTS: No clear affect was noted on urine strip semi-quantitative or automated chemistry analysis from the PureWick collection. There was a statistically significant decrease in microscopic measurements of white blood cells and crystals in the PureWick urine samples. DISCUSSION: This study supports the use of the PureWick external catheter for collection of samples for most urinalysis and urine chemistry tests.


Assuntos
Urinálise , Coleta de Urina , Catéteres , Feminino , Humanos , Contagem de Leucócitos , Leucócitos
12.
Psychiatr Rehabil J ; 44(3): 266-274, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34043406

RESUMO

Objective: This study sought to identify key ingredients of motivational interviewing (MI) associated with taking a step in the direction of competitive employment (CE) for unemployed veterans with serious mental illness (SMI). Method: Data were analyzed from 195 audiotaped MI sessions targeted to employment conducted with 39 veterans with SMI. Sessions were coded and analyzed to identify components of MI practice predictive of taking any step in the direction of CE (e.g., asking for a referral to supported employment or conducting a job search). Predictor variables were (a) counselor MI talk behaviors and adherence to MI technical and relational principles and (b) client intensity and frequency of change talk and sustain talk. Covariates were age, gender, race, duration of unemployment, receipt of disability income, health status, work importance, work confidence, mental health diagnosis, and session number. Generalized estimating equations were used to create multivariate models. Results: After controlling for session number, work importance, work confidence and duration of unemployment, variables significant in the adjusted multivariate model were intensity of client change talk and sustain talk and counselor adherence to MI technical principles of cultivating change talk and softening sustain talk. Conclusions and Implications for Practice: Findings suggest that change talk and sustain talk during counseling sessions are associated with taking a step toward employment and that counseling focused on cultivating change talk and softening sustain talk increases the likelihood that unemployed veterans with SMI will take steps toward becoming competitively employed. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Assuntos
Entrevista Motivacional , Veteranos , Emprego , Humanos , Processos Mentais
13.
Prog Neurobiol ; 199: 101962, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33242571

RESUMO

Across sensory systems, temporal frequency information is progressively transformed along ascending central pathways. Despite considerable effort to elucidate the mechanistic basis of these transformations, they remain poorly understood. Here we used a novel constellation of approaches, including whole-cell recordings and focal pharmacological manipulation, in vivo, and new computational algorithms that identify conductances resulting from excitation, inhibition and active membrane properties, to elucidate the mechanisms underlying the selectivity of midbrain auditory neurons for long temporal intervals. Surprisingly, we found that stimulus-driven excitation can be increased and its selectivity decreased following attenuation of inhibition with gabazine or intracellular delivery of fluoride. We propose that this nonlinear interaction is due to shunting inhibition. The rate-dependence of this inhibition results in the illusion that excitation to a cell shows greater temporal selectivity than is actually the case. We also show that rate-dependent depression of excitation, an important component of long-interval selectivity, can be decreased after attenuating inhibition. These novel findings indicate that nonlinear shunting inhibition plays a key role in shaping the amplitude and interval selectivity of excitation. Our findings provide a major advance in understanding how the brain decodes intervals and may explain paradoxical temporal selectivity of excitation to midbrain neurons reported previously.


Assuntos
Mesencéfalo , Neurônios , Estimulação Acústica , Técnicas de Patch-Clamp
14.
Nature ; 432(7018): 753-8, 2004 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-15592413

RESUMO

Modern theories of learned vocal behaviours, such as human speech and singing in songbirds, posit that acoustic communication signals are reproduced from memory, using auditory feedback. The nature of these memories, however, is unclear. Here we propose and test a model for how complex song structure can emerge from sparse sequence information acquired during tutoring. In this conceptual model, a population of combination-sensitive (phrase-pair) detectors is shaped by early exposure to song and serves as the minimal representation of the template necessary for generating complete song. As predicted by the model, birds that were tutored with only pairs of normally adjacent song phrases were able to assemble full songs in which phrases were placed in the correct order; birds that were tutored with reverse-ordered phrase pairs sang songs with reversed phrase order. Birds that were tutored with all song phrases, but presented singly, failed to produce normal, full songs. These findings provide the first evidence for a minimal requirement of sequence information in the acoustic model that can give rise to correct song structure.


Assuntos
Aprendizagem/fisiologia , Pardais/fisiologia , Vocalização Animal , Estimulação Acústica , Animais , Masculino , Memória/fisiologia , Modelos Biológicos , Especificidade da Espécie
15.
Genes (Basel) ; 12(1)2020 12 24.
Artigo em Inglês | MEDLINE | ID: mdl-33374332

RESUMO

Increasing evidence suggests a role of epigenetic mechanisms at chromosome 8q24, an important cancer genetic susceptibility region, in prostate cancer. We investigated whether MYC DNA methylation at 8q24 (six CpG sites from exon 3 to the 3' UTR) in prostate tumor was associated with tumor aggressiveness (based on Gleason score, GS), and we incorporated RNA expression data to investigate the function. We accessed radical prostatectomy tissue for 50 Caucasian and 50 African American prostate cancer patients at the University of Maryland Medical Center, selecting an equal number of GS 6 and GS 7 cases per group. MYC DNA methylation was lower in tumor than paired normal prostate tissue for all six CpG sites (median difference: -14.74 to -0.20 percentage points), and we observed similar results for two nearby sites in The Cancer Genome Atlas (p < 0.0001). We observed significantly lower methylation for more aggressive (GS 7) than less aggressive (GS 6) tumors for three exon 3 sites (for CpG 212 (chr8:128753145), GS 6 median = 89.7%; GS 7 median = 85.8%; p-value = 9.4 × 10-4). MYC DNA methylation was not associated with MYC expression, but was inversely associated with PRNCR1 expression after multiple comparison adjustment (q-value = 0.04). Findings suggest that prostate tumor MYC exon 3 hypomethylation is associated with increased aggressiveness.


Assuntos
Biomarcadores Tumorais/genética , Próstata/patologia , Neoplasias da Próstata/diagnóstico , Proteínas Proto-Oncogênicas c-myc/genética , Adulto , Idoso , Estudos de Coortes , Ilhas de CpG/genética , Metilação de DNA , Epigênese Genética , Éxons/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Próstata/cirurgia , Prostatectomia , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Neoplasias da Próstata/cirurgia , RNA Longo não Codificante/genética
16.
J Neurosci ; 28(21): 5481-93, 2008 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-18495882

RESUMO

Sound duration can play a pivotal role in the reproductive behavior of anuran amphibians. Here, we report the first whole-cell recordings from duration-selective neurons in the anuran torus semicircularis, in vivo. We show that most short-pass duration-selective cells exhibited short-latency inhibition and delayed excitation. The duration of the inhibition increased with tone burst duration. Hence, for long-duration tone bursts, inhibition overlapped with excitation, reducing or eliminating spikes; no postinhibitory rebound was present. Other short-pass cells, however, showed inhibition only for long-duration tone bursts. Bandpass duration selectivity also involved interplay between inhibition and excitation; inhibition negated excitation with tone bursts that exceeded the optimum duration. Additionally, however, bandpass selectivity arose from stimulus-dependent excitation; tone bursts of sufficiently long duration were required to elicit excitation. Similarly, long-pass neurons showed inhibition and duration-dependent enhancement of excitation; long-pass selectivity resulted from enhanced excitation outlasting the transient inhibition or, in some cases, excitation overriding concurrent inhibition. Last, we evaluated the stimulus specificity of duration-selective neurons to variations in pulse repetition rate. We show that (1) most neurons that exhibited long-pass selectivity for tone-burst duration nonetheless responded to short-duration pulses when repeated at particular rates, and (2) some neurons that showed selectivity for tone burst duration also showed selectivity for pulse train duration. These novel response profiles appear to result from interplay between inhibition and time- and activity-dependent changes in excitation strength. These findings are discussed in the context of prevailing models of duration selectivity and acoustic communication in anurans.


Assuntos
Mesencéfalo/citologia , Inibição Neural/fisiologia , Neurônios Aferentes/fisiologia , Estimulação Acústica/métodos , Potenciais de Ação/fisiologia , Animais , Anuros , Relação Dose-Resposta à Radiação , Estimulação Elétrica , Potenciais Pós-Sinápticos Inibidores/fisiologia , Potenciais Pós-Sinápticos Inibidores/efeitos da radiação , Técnicas de Patch-Clamp/métodos , Fatores de Tempo
17.
Arch Pathol Lab Med ; 143(10): 1259-1264, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30969156

RESUMO

CONTEXT.­: Cystoisospora belli is an intracellular parasite associated with gastrointestinal disease in immunocompromised hosts. Although infection has been classically associated with intestinal disease, studies have identified Cystoisospora in the gallbladder of immunocompetent patients based on hematoxylin-eosin morphology. Recently, the identity of this histologic finding as Cystoisospora has been questioned based on negative results of nucleic acid studies. OBJECTIVE.­: To determine the prevalence of this histologic feature in pediatric patients, we retrospectively reviewed all cholecystectomy specimens from a pediatric hospital during a 24-month period. DESIGN.­: In 180 cholecystectomy specimens, we identified 11 cases (6.1%) with classical histologic features previously described to represent Cystoisospora organisms. To further investigate these structures, we retrieved tissue from paraffin-embedded blocks and performed electron microscopy. RESULTS.­: Ultrastructural examination identified ovoid perinuclear cytoplasmic structures composed of dense fibrillar aggregates rather than organisms. Patients with positive cases were similar in age to controls (positive cases: mean patient age 13.4 years [range, 2-23 years]; negative cases: mean patient age 14.7 years [range, 12 weeks-31 years]; P = .35). There was no significant association of this finding with cholelithiasis (54.5% versus 65.1%, P = .52), cholesterolosis (0% versus 22.5%, P = .12), acute cholecystitis (9.1% versus 10.1%, P > .99), or chronic cholecystitis (45.5% versus 66.3%, P = .20). CONCLUSIONS.­: To our knowledge, this is the first positive identification of these structures as cytoplasmic fibrillar aggregates rather than parasitic inclusions by ultrastructural examination, and the first study of this histologic finding in pediatric cholecystectomies.


Assuntos
Doenças da Vesícula Biliar/diagnóstico por imagem , Corpos de Inclusão/ultraestrutura , Adolescente , Adulto , Criança , Pré-Escolar , Colecistectomia , Epitélio/diagnóstico por imagem , Vesícula Biliar/diagnóstico por imagem , Humanos , Hospedeiro Imunocomprometido , Lactente , Estudos Retrospectivos , Adulto Jovem
18.
J Neurosci ; 27(49): 13384-92, 2007 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-18057196

RESUMO

The intervals between acoustic elements are important in audition. Although neurons have been recorded that show interval tuning, the underlying mechanisms are unclear. The anuran auditory system is well suited for addressing this problem. One class of midbrain neurons in anurans responds selectively over a narrow range of pulse-repetition rates (PRRs) and only after several sound pulses have occurred with the "correct" timing. This "interval-counting" process can be reset by a single incorrect interval. Here we show, from whole-cell patch recordings of midbrain neurons in vivo, that these computations result from interplay between inhibition and rate-dependent excitation. An individual pulse or slowly repeated pulses elicited inhibition and subthreshold excitation. Excitation was markedly enhanced, however, when PRR was increased over a neuron-specific range. Spikes were produced when the enhanced excitation overcame the inhibition. Interval-number thresholds were positively correlated with the strength of inhibition and number of intervals required to augment the excitation. Accordingly, interval-number thresholds decreased when inhibition was attenuated by loading cells with cesium fluoride. The selectivity of these neurons for the interpulse interval, and therefore PRR, was related to the time course of excitatory events and the rate dependence of enhancement; for cells that were tuned to longer intervals, EPSPs were broader, and enhancement occurred at slower PRRs. The frequency tuning of the inhibition generally spanned that of the excitation, consistent with its role in temporal computation. These findings provide the first mechanistic understanding of interval selectivity and counting in the nervous system.


Assuntos
Vias Auditivas/fisiologia , Potenciais Pós-Sinápticos Excitadores/fisiologia , Potenciais Pós-Sinápticos Inibidores/fisiologia , Inibição Neural/fisiologia , Estimulação Acústica/métodos , Animais , Córtex Auditivo/fisiologia , Percepção Auditiva/fisiologia , Nervo Coclear/fisiologia , Rana pipiens
19.
Nat Neurosci ; 5(10): 934-6, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12219094

RESUMO

Many acoustic communication signals, including human speech and music, consist of a precise temporal arrangement of discrete elements, but it is unclear whether this precise temporal patterning is required to activate the sensory neurons that mediate signal recognition. In a variety of systems, neurons respond selectively when two or more sound elements are presented in a particular temporal order and the precise relative timing of these elements is particularly important for 'delay-tuned' neurons, including 'tracking' types, in bats. Here we show that one class of auditory neurons in the midbrain of anurans (frogs and toads) responds only to a series of specific interpulse intervals (IPIs); in the most selective cases, a single interval that is slightly longer or shorter than the requisite interval can reset this interval-counting process.


Assuntos
Estimulação Acústica/métodos , Potenciais de Ação/fisiologia , Mesencéfalo/fisiologia , Neurônios/fisiologia , Estimulação Acústica/estatística & dados numéricos , Animais , Anuros
20.
J Subst Abuse Treat ; 92: 27-34, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30032941

RESUMO

BACKGROUND: The technical hypothesis of Motivational Interviewing (MI) proposes that: (a) client talk favoring behavior change, or Change Talk (CT) is associated with better behavior change outcomes, whereas client talk against change, or Sustain Talk (ST) is associated with less favorable outcomes, and (b) specific therapist verbal behaviors influence whether client CT or ST occurs. MI consistent (MICO) therapist behaviors are hypothesized to be positively associated with more client CT and MI inconsistent (MIIN) behaviors with more ST. Previous studies typically examine session-level frequency counts or immediate lag sequential associations between these variables. However, research has found that the strongest determinant of CT or ST is the client's previous CT or ST statement. Therefore, the objective of this paper was to examine the association between therapist MI skills and subsequent client talk, while accounting for prior client talk. METHODS: We analyzed data from a manualized MI intervention targeting both alcohol misuse and sexual risk behavior in 132 adults seen in two hospital emergency departments. Transcripts of encounters were coded using the Motivational Interviewing Skills Code (MISC 2.5) and an additional measure, the Generalized Behavioral Intervention Analysis System (GBIAS). Using these measures, we analyzed the association between client talk following specific classifications of MICO skills, with the client's prior statement as a potential confounder or effect modifier. RESULTS: With closed questions as the reference category, therapist simple reflections and paraphrasing reflections were associated with significantly greater odds of maintaining client talk as CT or ST. Open questions and complex reflections were associated with significantly greater odds of CT following ST, were not associated significantly with more ST following ST, and were associated with more ST following CT (i.e., through an association with less Follow Neutral). CONCLUSIONS: Simple and paraphrasing reflections appear to maintain client CT but are not associated with transitioning client ST to CT. By contrast, complex reflections and open questions appeared to be more strongly associated with clients moving from ST to CT than other techniques. These results suggest that counselors may differentially employ certain MICO technical skills to elicit continued CT and move participants toward ST within the MI dialogue.


Assuntos
Alcoolismo/reabilitação , Competência Clínica , Conselheiros/normas , Entrevista Motivacional/métodos , Adolescente , Adulto , Serviço Hospitalar de Emergência , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Entrevista Motivacional/normas , Relações Profissional-Paciente , Assunção de Riscos , Comportamento Sexual , Adulto Jovem
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