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1.
Artigo em Inglês | MEDLINE | ID: mdl-38809485

RESUMO

Orthostatic hypotension (OH) is a form of orthostatic intolerance (OI) and a key physiological indicator of autonomic dysfunction that is associated with an increased risk of major cerebrocardiovascular events. Symptoms of cerebral hypoperfusion have been reported in patients with OH, which worsens symptoms and increases the risk of syncope. Since pharmacological interventions increase blood pressure (BP) independent of posture and do not restore normal baroreflex control, nonpharmacological treatments are considered the foundation of OH management. While reductions in cerebral blood flow velocity (CBFv) during orthostatic stress are associated with a decrease in end-tidal CO2 (EtCO2) and hypocapnia in patients with OI, their contribution to the severity of OH is not well understood. These measures have been physiological targets in a wide variety of biofeedback interventions. This study explored the relationship between cardiovascular autonomic control, EtCO2 and cerebral hypoperfusion in patients (N = 72) referred for OI. Patients with systolic OH were more likely to be male, older, demonstrate reduced adrenal and vagal baroreflex sensitivity, and reduced cardiovagal control during head-up tilt (HUT) than patients without systolic OH. Greater reduction in CBFv during HUT was associated with a larger reduction in ETCO2 and systolic BP during HUT. While deficits in cardiovascular autonomic control played a more important role in systolic OH, reduced EtCO2 was a major contributor to orthostatic cerebral hypoperfusion. These findings suggest that biofeedback treatments targeting both the autonomic nervous system and EtCO2 should be part of nonpharmacological interventions complementing the standard of care in OH patients with symptoms of cerebral hypoperfusion.

2.
Appl Psychophysiol Biofeedback ; 47(2): 107-119, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35171410

RESUMO

Chronic orthostatic intolerance (COI) is defined by changes in heart rate (HR), blood pressure (BP), respiration, symptoms of cerebral hypoperfusion and sympathetic overactivation. Postural tachycardia syndrome (POTS) is the most common form of COI in young adults and is defined by an orthostatic increase in heart rate (HR) of ≥ 30 bpm in the absence of orthostatic hypotension. However, some patients referred for evaluation of COI symptoms do not meet the orthostatic HR response criterion of POTS despite debilitating symptoms. Such patients are ill defined, posing diagnostic and therapeutic challenges. This study explored the relationship among cardiovascular autonomic control, the orthostatic HR response, EtCO2 and the severity of orthostatic symptoms and fatigue in patients referred for evaluation of COI. Patients (N = 108) performed standardized testing protocol of the Autonomic Reflex Screen and completed the Composite Autonomic Symptom Score (COMPASS-31) and the Fatigue Severity Scale (FSS). Greater severity of COI was associated with younger age, larger phase IV amplitude in the Valsalva maneuver and lower adrenal baroreflex sensitivity. Greater fatigue severity was associated with a larger reduction in ETCO2 during 10 min of head-up tilt (HUT) and reduced low-frequency (LF) power of heart rate variability. This study suggests that hemodynamic changes associated with the baroreflex response and changes in EtCO2 show a stronger association with the severity of orthostatic symptoms and fatigue than the overall orthostatic HR response in patients with COI.


Assuntos
Intolerância Ortostática , Síndrome da Taquicardia Postural Ortostática , Pressão Sanguínea/fisiologia , Fadiga , Frequência Cardíaca/fisiologia , Humanos , Intolerância Ortostática/diagnóstico , Síndrome da Taquicardia Postural Ortostática/diagnóstico , Teste da Mesa Inclinada , Adulto Jovem
3.
Clin Auton Res ; 26(2): 87-95, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26758567

RESUMO

Hypertension and obesity are serious health problems that have been associated with an increased risk of cardiovascular disease (CVD). We recently showed a relationship between hypertension, obesity and cardiovagal control in a sample of Native and Mexican Americans at high risk of alcohol use disorders (AUD). While studies have shown that Native and Mexican Americans exhibit high rates of AUD, the consequences of AUD on CVD risk factors and their relationship with cardiovascular autonomic control is not well understood in these ethnic groups. This study investigated whether an association could be demonstrated between cardiovascular autonomic control and several CVD risk factors in Native and Mexican American men and women (n = 228) who are literate in English and are residing legally in San Diego County. Participants with lifetime history of AUD showed higher rates of systolic and diastolic hypertension and obesity than participants without lifetime AUD. Lifetime AUD was significantly associated with reduced HR response to deep breathing (HRDB) measure of cardiovagal control, higher current drinking quantity, and obesity. Reduced HRDB was also associated with increased systolic pre-hypertension or hypertension (pre-/hypertension) and with higher diastolic blood pressure in a linear regression model that included several diagnostic and demographic variables. HRDB and time- and frequency-domain measures of cardiovagal control were significantly reduced in participants with diastolic pre-/hypertension. These data suggest that lower cardiovagal control may play a role in the prevalence of systolic and diastolic pre-/hypertension in a community sample with a history of alcohol and substance use disorders.


Assuntos
Alcoolismo/fisiopatologia , Sistema Nervoso Autônomo/fisiopatologia , Doenças Cardiovasculares/fisiopatologia , Fenômenos Fisiológicos Cardiovasculares , Adolescente , Adulto , Alcoolismo/complicações , Doenças Cardiovasculares/complicações , Feminino , Humanos , Hipertensão/complicações , Hipertensão/fisiopatologia , Indígenas Norte-Americanos , Masculino , Americanos Mexicanos , Obesidade/complicações , Obesidade/fisiopatologia , Fatores de Risco , Adulto Jovem
4.
J Nerv Ment Dis ; 204(12): 877-884, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27483114

RESUMO

Sensory gating deficits are commonly found in patients with schizophrenia. However, there is still scarce research on this issue. Thirty-eight patients with first-episode psychosis (FEP) were compared to thirty-eight controls. A condition-test paradigm of event-related potentials (ERP), prepulse inhibition (PPI), and some specific tasks of the MATRICS Consensus Cognitive Battery (MCCB) were used (i.e., TMT, BACS-SC, and Fluency for processing speed and CPT-IP for attention and vigilance). The ERP components measured were P50, N1, and P2. The PPI intervals examined were 30, 60, and 120 msec. Regarding the MCCB, processing speed and attention/vigilance cognitive domains were selected. FEP patients showed significant deficits in N1 and P2 components, at 30 and 60 PPI levels and in all the MCCB subtests selected. We obtained significant relationships in N1 with PPI-60, and with one MCCB subtest for processing speed. In addition, this same subtest showed significant association with P2. Therefore, sensory gating functioning is widely impaired since the very early stages of schizophrenia.


Assuntos
Testes Neuropsicológicos , Transtornos Psicóticos/fisiopatologia , Reflexo de Sobressalto/fisiologia , Esquizofrenia/fisiopatologia , Psicologia do Esquizofrênico , Filtro Sensorial/fisiologia , Estimulação Acústica/métodos , Adulto , Eletroencefalografia/métodos , Feminino , Humanos , Masculino , Transtornos Psicofisiológicos/diagnóstico , Transtornos Psicofisiológicos/fisiopatologia , Transtornos Psicofisiológicos/psicologia , Psicofisiologia , Transtornos Psicóticos/diagnóstico , Transtornos Psicóticos/psicologia , Esquizofrenia/diagnóstico
5.
Twin Res Hum Genet ; 17(2): 80-8, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24588897

RESUMO

A lifetime history of alcohol dependence has been associated with elevations in neuroticism in Mexican American young adults. The identification of genetic markers associated with neuroticism and their influence on the development of alcohol use disorders (AUD) may contribute to our understanding of the relationship between personality traits and the increased risk of AUD in Mexican Americans. The purpose of this study was to investigate associations between neuroticism and 13 single nucleotide polymorphisms (SNPs) in the nicotinic acetylcholine (nAChR) α5-subunit (CHRNA5) and α3-subunit (CHRNA3) genes in young adult Mexican American men and women. Participants were 465 young adult Mexican American men and women who are literate in English and are residing legally in San Diego County. Each participant gave a blood sample and completed a structured diagnostic interview. Neuroticism was assessed using the Maudsley Personality Inventory. The minor alleles of four CHRNA5 polymorphisms (rs588765, rs601079, rs680244 and rs555018) and three CHRNA3 polymorphisms (rs578776, rs6495307 and rs3743078) showed associations with neuroticism. Several of these SNPs also displayed nominal associations with DSM-IV alcohol and nicotine dependence, but tests of mediation suggested that these relations could be partially explained by the presence of co-occurring neuroticism. These findings suggest that genetic variations in nicotinic receptor genes may influence the development of neuroticism, which in turn is involved in the development of AUDs and nicotine dependence in Mexican American young adults.


Assuntos
Transtornos de Ansiedade/genética , Americanos Mexicanos/genética , Proteínas do Tecido Nervoso/genética , Receptores Nicotínicos/genética , Transtornos de Ansiedade/epidemiologia , Feminino , Humanos , Desequilíbrio de Ligação , Masculino , Americanos Mexicanos/estatística & dados numéricos , Neuroticismo , Polimorfismo de Nucleotídeo Único , Adulto Jovem
6.
Proc Natl Acad Sci U S A ; 108(48): 19413-8, 2011 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-22087007

RESUMO

The voltage-gated sodium channel Na(v)1.8 is known to function in the transmission of pain signals induced by cold, heat, and mechanical stimuli. Sequence variants of human Na(v)1.8 have been linked to altered cardiac conduction. We identified an allele of Scn10a encoding the α-subunit of Na(v)1.8 among mice homozygous for N-ethyl-N-nitrosourea-induced mutations. The allele creates a dominant neurobehavioral phenotype termed Possum, characterized by transient whole-body tonic immobility induced by pinching the skin at the back of the neck ("scruffing"). The Possum mutation enhanced Na(v)1.8 sodium currents and neuronal excitability and heightened sensitivity of mutants to cold stimuli. Striking electroencephalographic changes were observed concomitant with the scruffing-induced behavioral change. In addition, electrocardiography demonstrated that Possum mice exhibited marked sinus bradycardia and R-R variability upon scruffing, abrogated by infusion of atropine. However, atropine failed to prevent or mitigate the tonic immobility response. Hyperactive sodium conduction via Na(v)1.8 thus leads to a complex neurobehavioral phenotype, which resembles catatonia in schizophrenic humans and tonic immobility in other mammals upon application of a discrete stimulus; no other form of mechanosensory stimulus could induce the immobility phenotype. Our data confirm the involvement of Na(v)1.8 in transducing pain initiated by cold and additionally implicate Na(v)1.8 in previously unknown functions in the central nervous system and heart.


Assuntos
Resposta de Imobilidade Tônica/fisiologia , Mutação/genética , Fenótipo , Canais de Sódio/genética , Animais , Atropina/farmacologia , Bradicardia/genética , Eletrocardiografia , Eletroencefalografia , Resposta de Imobilidade Tônica/efeitos dos fármacos , Camundongos , Canal de Sódio Disparado por Voltagem NAV1.8 , Canais de Sódio/fisiologia
7.
Neurobiol Learn Mem ; 92(3): 429-38, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19531380

RESUMO

Changes in the state of CREB phosphorylation and in LTP in the hippocampus have been associated with learning and memory. Here we show that galanin, the neuropeptide released in the hippocampal formation from cholinergic and noradrenergic fibers, that has been shown to produce impairments in memory consolidation in the Morris water maze task inhibits both LTP and CREB phosphorylation in the rat hippocampus in vivo. While there are many transmitters regulating CREB phosphorylation none has been shown to suppress behaviorally-induced hippocampal CREB phosphorylation as potently as galanin. The in vivo inhibition of dentate gyrus-LTP and of CREB phosphorylation by the agonist occupancy of GalR1 and GalR2-type galanin receptors provides strong in vivo cellular and molecular correlates to galanin-induced learning deficits and designates galanin as a major regulator of the memory consolidation process.


Assuntos
Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Galanina/metabolismo , Hipocampo/fisiopatologia , Potenciação de Longa Duração/fisiologia , Transtornos da Memória/fisiopatologia , Neurônios/fisiologia , Precursores de Proteínas/metabolismo , Animais , Western Blotting , Giro Denteado/fisiopatologia , Eletrodos Implantados , Potenciais Evocados , Imuno-Histoquímica , Masculino , Memória/fisiologia , Proteínas Associadas aos Microtúbulos/metabolismo , Fosforilação , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
8.
Pharmacol Biochem Behav ; 92(1): 68-75, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18996142

RESUMO

Ventral tegmental area (VTA) GABA neurons appear to be critical regulators of mesocorticolimbic dopamine (DA) neurotransmission, which has been implicated in alcohol reward. The aim of this study was to evaluate the effects of low-dose "non-contingent" intravenous (IV) ethanol (0.01-0.1 g/kg) on VTA GABA neuron firing rate and synaptic responses, as well as VTA GABA neuron firing rate during low-dose "contingent" IV ethanol self-administration. Intravenous administration of 0.01-0.03 g/kg ethanol significantly increased VTA GABA neuron firing rate and afferent-evoked synaptic responses. In the runway self-administration paradigm, presentation of an olfactory cue (S+; almond extract) or no-cue (S-; no odor) in the Start box was paired with IV administration of low-dose ethanol (0.01 g/kg) or saline in the Target box. Runway excursion times decreased significantly in association during S+, and increased significantly during S- conditions. The firing rate of VTA GABA neurons markedly increased when rats received 0.01 g/kg IV ethanol in the Target box. VTA GABA neuron firing increased in the Start box of the runway in association with S+, but not S-. These findings demonstrate that VTA GABA neurons are activated by low-dose IV ethanol and that their firing rate increases in anticipation of ethanol reward.


Assuntos
Depressores do Sistema Nervoso Central/farmacologia , Condicionamento Operante/efeitos dos fármacos , Etanol/farmacologia , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Área Tegmentar Ventral/efeitos dos fármacos , Área Tegmentar Ventral/fisiologia , Ácido gama-Aminobutírico/fisiologia , Potenciais de Ação/efeitos dos fármacos , Animais , Depressores do Sistema Nervoso Central/administração & dosagem , Depressores do Sistema Nervoso Central/efeitos adversos , Eletrofisiologia , Etanol/administração & dosagem , Etanol/efeitos adversos , Espaço Extracelular/efeitos dos fármacos , Espaço Extracelular/fisiologia , Injeções Intravenosas , Masculino , Ratos , Ratos Wistar , Recompensa , Autoadministração , Síndrome de Abstinência a Substâncias/psicologia , Sinapses/efeitos dos fármacos , Área Tegmentar Ventral/citologia
10.
Brain Res ; 1194: 28-36, 2008 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-18191821

RESUMO

Age-related developmental differences in sensitivity to the acute effects of alcohol may play an important role in the development of alcoholism. The present study was designed to evaluate the acute effects of alcohol on cortical electroencephalogram (EEG) in adolescent (P36) and adult (P78) Wistar rats. Five minutes of EEG was recorded after administration of 0, 0.75 or 1.5 g/kg alcohol. The righting reflex was performed to measure the sedative effects of alcohol (3.5 g/kg) and total sleeping time for each rat. Our results showed that alcohol (1.5 g/kg) increased power in the 1-2 Hz band and decreased the power in the 32-50 Hz band in the parietal cortical region of adolescent rats. Alcohol (1.5 g/kg) also increased stability of the EEG power in the slow-wave frequency bands (2-4 Hz, 4-6 Hz, and 6-8 Hz) of adolescent rats. In the frontal cortex of adult rats, but not in adolescent rats, alcohol (1.5 or 0.75 g/kg) decreased the power in the 16-32 Hz frequency band. Alcohol (1.5 g/kg) differentially increased power in a multiple of slow-wave frequency bands (2-4 Hz and 4-6 Hz) in the parietal cortex of adult rats as compared to adolescent rats. Adolescent rats were shown significantly shorter sleeping time and higher blood alcohol levels after regaining reflex than adult rats. Our results provide additional evidence of age-related differences in the effects of acute alcohol on cortical EEG, sedation and tolerance.


Assuntos
Envelhecimento/fisiologia , Córtex Cerebral/efeitos dos fármacos , Eletroencefalografia , Etanol/administração & dosagem , Hipnóticos e Sedativos/administração & dosagem , Reflexo/efeitos dos fármacos , Envelhecimento/efeitos dos fármacos , Análise de Variância , Animais , Animais Recém-Nascidos , Córtex Cerebral/anatomia & histologia , Relação Dose-Resposta a Droga , Masculino , Ratos , Ratos Wistar , Tempo de Reação/efeitos dos fármacos
11.
Alcohol Clin Exp Res ; 32(12): 2062-73, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18828807

RESUMO

BACKGROUND: Previous studies have demonstrated that adolescent and adult rats show differential sensitivity to many of the acute effects of alcohol. We recently reported evidence of developmental differences in the effects of acute alcohol on the cortical electroencephalogram. However, it is unclear whether developmental differences are also observed in other neurophysiological and neurobehavioral measurements known to be sensitive to alcohol exposure. The present study determined the age-related effects of acute alcohol on behavioral and event-related potential (ERP) responses to acoustic startle (AS) and prepulse inhibition (PPI). METHODS: Male adolescent and adult Wistar rats were implanted with cortical recording electrodes. The effects of acute alcohol (0.0, 0.75, and 1.5 g/kg) on behavioral and ERP responses to AS and PPI were assessed. RESULTS: Acute alcohol (0.75 and 1.5 g/kg) significantly reduced the behavioral and electrophysiological response to AS in adolescent and adult rats. Both 0.75 and 1.5 g/kg alcohol significantly enhanced the behavioral response to PPI in adolescent, but not in adult rats. During prepulse + pulse trials, 1.5 g/kg alcohol significantly increased the N10 pulse response in the adolescent frontal cortex. Acute alcohol (0.75 and 1.5 g/kg) also increased the N1 ERP pulse response to prepulse stimuli in frontal and parietal cortices in adult rats, but not in adolescent rats. CONCLUSIONS: These data suggest that alcohol's effect on behavioral and electrophysiological indices of AS do not differ between adults and adolescents whereas developmental stage does appear to significantly modify alcohol-influenced response to PPI.


Assuntos
Etanol/intoxicação , Potenciais Evocados Auditivos/efeitos dos fármacos , Reflexo de Sobressalto/efeitos dos fármacos , Estimulação Acústica/métodos , Fatores Etários , Animais , Modelos Animais de Doenças , Eletroencefalografia/efeitos dos fármacos , Eletroencefalografia/métodos , Potenciais Evocados/efeitos dos fármacos , Potenciais Evocados/fisiologia , Potenciais Evocados Auditivos/fisiologia , Masculino , Rede Nervosa/efeitos dos fármacos , Rede Nervosa/fisiologia , Ratos , Ratos Wistar , Reflexo de Sobressalto/fisiologia
12.
Alcohol Clin Exp Res ; 32(10): 1752-62, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18652596

RESUMO

BACKGROUND: Despite evidence showing persistent changes in N-methyl-D-aspartate (NMDA)-receptor function following ethanol (EtOH) exposure, the contribution of NMDA systems to the long-term neurophysiological consequences of adolescent EtOH exposure is unclear. The aims of this study were the following: (1) to determine whether adolescent EtOH exposure produces neurophysiological changes after a prolonged withdrawal period in adult rats and (2) to assess protracted alterations in neurophysiological responses to the NMDA antagonist MK-801 in adult rats exposed to EtOH during adolescence. METHODS: Adolescent male Wistar rats were exposed to EtOH vapor for 12 h/d for 5 weeks. The effects of MK-801 (0.0 to 0.1 mg/kg, intraperitoneally) on the electroencephalogram (EEG) and auditory event-related potentials (ERPs) were assessed after 8 weeks of abstinence from EtOH. RESULTS: Experiments in aim 1 revealed that adolescent EtOH exposure reduced EEG variability in the frontal cortex in the 4 to 6 Hz band but had no effect on cortical and hippocampal EEG power and ERPs. Experiments in aim 2 showed that MK-801 significantly reduced EEG power in the parietal cortex (4 to 6 Hz, 6 to 8 Hz, 8 to 16 Hz, 16 to 32 Hz) and hippocampus (16 to 32 Hz) and EEG variability in the parietal cortex (6 to 8 Hz, 16 to 32 Hz) following adolescent EtOH exposure. MK-801 produced a significant decrease in hippocampal EEG variability (4 to 6 Hz, 8 to 16 Hz, 16 to 32 Hz) in control, but not in EtOH-exposed rats. MK-801 reduced frontal P1 ERP amplitude and latency in response to the rare tone in EtOH-exposed rats compared to controls. In contrast, MK-801 significantly reduced P3 ERP amplitude and latency in control, but not in EtOH-exposed rats. CONCLUSIONS: The effects of MK-801 on hippocampal EEG variability and P3 ERP amplitude and latency are significantly attenuated after a prolonged withdrawal period following adolescent EtOH exposure. However, the inhibitory effects of MK-801 on cortical and hippocampal EEG power were enhanced in rats exposed to EtOH during adolescence. Taken together, these data suggest protracted changes in NMDA systems following adolescent EtOH exposure.


Assuntos
Depressores do Sistema Nervoso Central/farmacologia , Córtex Cerebral/efeitos dos fármacos , Maleato de Dizocilpina/farmacologia , Etanol/farmacologia , Potenciais Evocados Auditivos/efeitos dos fármacos , Receptores de N-Metil-D-Aspartato/efeitos dos fármacos , Animais , Peso Corporal/efeitos dos fármacos , Eletroencefalografia , Etanol/sangue , Masculino , Ratos , Ratos Wistar , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Fatores de Tempo
13.
Int J Psychophysiol ; 131: 113-123, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-28679109

RESUMO

Although there has been much support for HRV Biofeedback as an effective intervention for various disorders, there is a lack of comprehension of the underlying mechanisms. The predominant theories of increased vagal efferents and baroreflex gain are insufficient in explaining the frequent observations that HRV Biofeedback impacts changes in constructs beyond ANS mediation, such as emotion regulation, attentional control, and self-regulatory reserve. It has been suspected that vagal afferent functioning may be the underlying mechanism, but little research has explored this. Previously, researchers measured cortical evoked potentials contingent to the heart, or an indication of vagal afferent functioning (Schandry et al., 1986). Twenty-five participants were randomly stratified to HRV Biofeedback or EMG Biofeedback for four sessions. Repeated measures ANOVAs revealed that the HRV group exhibited statistically significantly increased baseline Heartbeat Event-Related Potentials (updated term for 'evoked potential') while the relaxation control group did not. The results of this study provide initial support to the premise that HRV Biofeedback stimulates changes in the vagal afferent pathway that are longer lasting than simply the short term effects of breathing.


Assuntos
Biorretroalimentação Psicológica/métodos , Potenciais Evocados/fisiologia , Frequência Cardíaca/fisiologia , Nervo Vago/fisiologia , Adulto , Distribuição de Qui-Quadrado , Eletrocardiografia , Eletromiografia , Feminino , Humanos , Masculino , Fatores de Tempo , Adulto Jovem
14.
Brain Res ; 1158: 71-80, 2007 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-17570349

RESUMO

In order to gain insights on the function of the cellular prion protein (PrP(C)) sleep and the levels of the stress hormones corticosterone (CORT) and the adrenocorticotropic hormone (ACTH) before and after sleep deprivation (SD) were compared in two wild type (WT) mice strains and the following three PrP(C) transgenic lines: mice null for PrP(C) (mPrP(0/0)) and mice with specific and central expression of PrP in neurons (NSE-HPrP/mPrP(0/0)) or in glia cells (GFAP-HPrP/mPrP(0/0)). After SD mPrP(0/0) mice showed a larger degree of sleep fragmentation and of latency to enter rapid eye movement (REM) and non-REM sleep (NREM) than WT. During sleep recovery, the amount of NREM sleep and the slow-wave activity (SWA) were reduced in mPrP(0/0) mice. After SD, CORT and ACTH levels have distinct patterns in WT and mPrP(0/0). The NREM and SWA deficit was restored in NSE-HPrP/mPrP(0/0) mice but not in GFAP-HPrP/mPrP(0/0). Hormonal profile was only partially restored in NSE-HPrP/mPrP(0/0) mice and was similar to that of mPrP(0/0) and GFAP-HPrP/mPrP(0/0) mice. These findings demonstrate that neuronal, but not non-neuronal, PrP(C) is involved in sleep homeostasis and sleep continuity. They also suggest that neuronal PrP(c)-dependent hormonal regulation of HPA axis may contribute to the sleep homeostasis.


Assuntos
Príons/fisiologia , Privação do Sono/complicações , Sono/fisiologia , Estresse Psicológico/etiologia , Hormônio Adrenocorticotrópico/sangue , Análise de Variância , Animais , Ritmo Circadiano/fisiologia , Corticosterona/sangue , Eletroencefalografia/métodos , Eletromiografia/métodos , Proteína Glial Fibrilar Ácida/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fosfopiruvato Hidratase/genética , Príons/genética , Tempo de Reação , Sono/genética , Estresse Psicológico/genética , Estresse Psicológico/metabolismo , Fatores de Tempo
15.
Brain Res ; 1131(1): 112-7, 2007 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-17157827

RESUMO

Cleavage of the beta-amyloid precursor protein (APP) by alpha-secretase releases a secreted form of APP (sAPP) from cells. sAPP is released from neurons in an activity-dependent manner and is believed to play roles in synaptic plasticity and neuroprotection. We determined whether sAPP modulates electrophysiological and cerebrovascular processes in vivo. The effects of recombinant sAPP, applied by intracerebroventricular infusion, on hippocampal and cortical electroencephalographic (EEG) activity and hippocampal blood flow in young adult and middle-aged Long-Evans rats were measured. sAPP increased the power spectrum density of low frequency EEG bands in the hippocampus and cortex of middle-aged rats without affecting hippocampal blood flow. The neurophysiological effects of sAPP were observed in middle-aged, but not in young rats. The results of this study indicate that hippocampal and cortical electrophysiological processes are sensitive to sAPP, whereas the cerebral vasculature may not be regulated by sAPP. The age-dependent change in the sensitivity of neuronal activity to sAPP suggests the possibility of an important role for this APP product in brain functioning in mid life.


Assuntos
Precursor de Proteína beta-Amiloide/biossíntese , Encéfalo/metabolismo , Artérias Cerebrais/fisiologia , Circulação Cerebrovascular/fisiologia , Fármacos Neuroprotetores/metabolismo , Envelhecimento/fisiologia , Secretases da Proteína Precursora do Amiloide/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/farmacologia , Animais , Encéfalo/irrigação sanguínea , Encéfalo/efeitos dos fármacos , Artérias Cerebrais/efeitos dos fármacos , Córtex Cerebral/irrigação sanguínea , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Circulação Cerebrovascular/efeitos dos fármacos , Demência/tratamento farmacológico , Demência/metabolismo , Demência/fisiopatologia , Modelos Animais de Doenças , Eletroencefalografia/efeitos dos fármacos , Hipocampo/irrigação sanguínea , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Injeções Intraventriculares , Masculino , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/metabolismo , Transtornos da Memória/fisiopatologia , Fármacos Neuroprotetores/farmacologia , Ratos , Ratos Long-Evans , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes de Fusão/farmacologia , Vasodilatação/efeitos dos fármacos , Vasodilatação/fisiologia
16.
Pharmacol Biochem Behav ; 88(2): 148-57, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17764730

RESUMO

The relationship between the P450 component elicited by affective stimuli and: a personal history of alcohol dependence, antisocial personality disorder/conduct disorder (ASPD/CD) or affective anxiety disorders (ANYAXAF) was examined in Mexican Americans, a group with high rates of heavy drinking. Data from two hundred and twenty two young adults between the ages of 18 and 30 were used in the analyses. ERPs were collected using a task that required discrimination between faces with neutral, sad and happy facial expressions. DSM-IIIR diagnoses were obtained using a structured interview and personality traits were indexed using the Maudsley personality inventory. Men had significantly diminished P450 responses, when compared to women which were further reduced in men with ASPD/CD; whereas, a significant increase in P450 amplitudes was seen in those participants with ANYAXAF. P450 amplitudes were also significantly increased in men with high extraversion scores and in women with high neuroticism scores. No significant associations were seen between the P450 amplitude and the diagnosis of alcohol dependence. These data suggest that interpretations of P450 responses in Mexican Americans need to take into account the interactions between gender, the affective valence of the eliciting stimuli, as well as psychiatric status.


Assuntos
Alcoolismo/fisiopatologia , Potenciais Evocados/fisiologia , Americanos Mexicanos/psicologia , Personalidade/fisiologia , Adulto , Transtorno da Personalidade Antissocial/fisiopatologia , Transtornos de Ansiedade/fisiopatologia , Extroversão Psicológica , Feminino , Humanos , Masculino , Caracteres Sexuais
17.
J Neurosci ; 25(23): 5465-74, 2005 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-15944374

RESUMO

Urotensin II (UII) is a cyclic neuropeptide with strong vasoconstrictive activity in the peripheral vasculature. UII receptor mRNA is also expressed in the CNS, in particular in cholinergic neurons located in the mesopontine tegmental area, including the pedunculopontine tegmental (PPT) and lateral dorsal tegmental nuclei. This distribution suggests that the UII system is involved in functions regulated by acetylcholine, such as the sleep-wake cycle. Here, we tested the hypothesis that UII influences cholinergic PPT neuron activity and alters rapid eye movement (REM) sleep patterns in rats. Local administration of UII into the PPT nucleus increases REM sleep without inducing changes in the cortical blood flow. Intracerebroventricular injection of UII enhances both REM sleep and wakefulness and reduces slow-wave sleep 2. Intracerebroventricular, but not local, administration of UII increases cortical blood flow. Moreover, whole-cell recordings from rat-brain slices show that UII selectively excites cholinergic PPT neurons via an inward current and membrane depolarization that were accompanied by membrane conductance decreases. This effect does not depend on action potential generation or fast synaptic transmission because it persisted in the presence of TTX and antagonists of ionotropic glutamate, GABA, and glycine receptors. Collectively, these results suggest that UII plays a role in the regulation of REM sleep independently of its cerebrovascular actions by directly activating cholinergic brainstem neurons.


Assuntos
Acetilcolinesterase/metabolismo , Neurônios/fisiologia , Sono REM/fisiologia , Tegmento Mesencefálico/fisiologia , Urotensinas/fisiologia , Animais , Circulação Cerebrovascular , Eletroencefalografia , Eletromiografia , Técnicas In Vitro , Injeções Intraventriculares , Masculino , Neurônios/metabolismo , Técnicas de Patch-Clamp , Núcleo Tegmental Pedunculopontino/citologia , Núcleo Tegmental Pedunculopontino/fisiologia , Ratos , Ratos Sprague-Dawley , Receptores Acoplados a Proteínas G/metabolismo , Tegmento Mesencefálico/irrigação sanguínea , Tegmento Mesencefálico/citologia , Urotensinas/farmacologia , Vigília
18.
Int J Psychophysiol ; 60(2): 172-85, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16510201

RESUMO

Perspectives on the P300 event-related brain potential (ERP) are reviewed by outlining the distinction between the P3a and P3b subcomponents. The critical factor for eliciting P3a is how target/standard discrimination difficulty rather than novelty modulates task processing. The neural loci of P3a and P3b generation are sketched and a theoretical model is developed. P3a originates from stimulus-driven disruption of frontal attention engagement during task processing. P3b originates when temporal-parietal mechanisms process the stimulus information for memory storage. The neuropharmacological implications of this view are then outlined by evaluating how acute and chronic use of ethanol, marijuana, and nicotine affect P3a and P3b. The findings suggest that the circuit underlying ERP generation is influenced in a different ways for acute intake and varies between chronic use levels across drugs. Theoretical implications are assessed.


Assuntos
Encéfalo , Potenciais Evocados P300/efeitos dos fármacos , Potenciais Evocados P300/fisiologia , Neurofarmacologia , Neuropsicologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Eletroencefalografia/métodos , Humanos
19.
Am J Alzheimers Dis Other Demen ; 21(6): 416-23, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17267374

RESUMO

The use of magnetoencephalography to study neurophysiologic abnormalities associated with Alzheimer's disease is reviewed. The most consistent observation is that Alzheimer's disease patients exhibit an increase in focal slow-wave activity that covaried with cognitive performance. It is still unclear whether generation of focal slow-wave activity precedes or is a consequence of Alzheimer's disease-related neuropathology. Also reviewed is the use of magnetoencephalography to identify early functional changes preceding the diagnosis of dementia. Magnetoencephalography detected neurophysiologic abnormalities associated with cognitive deficits before the diagnosis of mild cognitive impairment. This is supported by evidence presented suggesting that some patients with subjective cognitive complaints, without evidence of dementia, show an increase in focal slow-wave generators. Further research is needed to determine whether the outstanding spatial and temporal resolution of the magnetoencephalography technique could complement other neuroimaging techniques in identifying neurophysiologic abnormalities preceding the diagnosis of Alzheimer's disease and mild cognitive impairment.


Assuntos
Doença de Alzheimer/diagnóstico , Doença de Alzheimer/fisiopatologia , Encéfalo/fisiopatologia , Magnetoencefalografia/métodos , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/epidemiologia , Encéfalo/anatomia & histologia , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/epidemiologia , Transtornos Cognitivos/fisiopatologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Testes Neuropsicológicos , Índice de Gravidade de Doença
20.
Arq Neuropsiquiatr ; 64(2B): 394-7, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16917607

RESUMO

This study determined whether the activity of the secondary motor cortex (M2) could be recorded during imagined movements (IM) of the right and left hand using magnetoencephalography (MEG). Results during IM were compared with a somatosensory trial during a passive tactile stimulation in one subject. During the somatosensory trial, dipoles were detected in somatosensory (SS) and motor primary (M1) areas, scoring 94.4-98.4% for SS, 1.6-5.6% for M1 and 0% for M2. During the IM trial, dipoles were detected in SS, M1 and M2 areas, scoring 61.1-68.8% for SS, 2.6-9.3% for M1 and 28.6-29.6% for M2. These data support the hypothesis that M2 areas are activated during imagined hand movements. This study aims for the development of a diagnosis test for patients with motor deficits by evaluating the whole somatomotor network with specific interest in M2 areas.


Assuntos
Lateralidade Funcional/fisiologia , Mãos/fisiologia , Imaginação/fisiologia , Córtex Motor/fisiologia , Movimento/fisiologia , Córtex Somatossensorial/fisiologia , Adulto , Mapeamento Encefálico , Humanos , Magnetoencefalografia , Masculino
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