RESUMO
BACKGROUND: People with intellectual disabilities (ID) are rarely asked about their experiences as users of psychological services and little is known about the views of clients with ID who have undergone cognitive behavioural therapy (CBT). This study aimed to gather the views of adults with ID who had recently taken part in a cluster randomised control trial (RCT) of a staff-delivered manualised CBT anger management group intervention. METHOD: A qualitative method, Interpretative Phenomenological Analysis (IPA), was employed and eleven participants were interviewed. The interviews took place after the intervention, within two weeks of the end of the group, to gain an understanding of service users' experiences of participating in a CBT group. RESULTS: IPA of the interview transcripts indicated that the intervention was experienced as effective and enjoyable and a number of themes were identified including: 'the importance of relationships', 'a new me', 'new and improved relationships', 'presenting myself in a positive light' and 'what the group didn't change'. CONCLUSIONS: The results will be discussed in the context of applying group CBT for adults with ID and implications for service development.
Assuntos
Terapia de Controle da Ira/métodos , Terapia Cognitivo-Comportamental/métodos , Deficiência Intelectual/psicologia , Relações Interpessoais , Psicoterapia de Grupo/métodos , Pesquisa Qualitativa , Adulto , Atitude Frente a Saúde , Análise por Conglomerados , Feminino , Humanos , Masculino , Satisfação do Paciente , Resultado do Tratamento , Adulto JovemRESUMO
BACKGROUND: Anger and aggression among adults with intellectual disability (ID) are associated with a range of adverse consequences for their well-being and that of their family or staff carers. The aims were to evaluate the effectiveness of an anger management intervention for adults with mild to moderate ID and to evaluate the costs of the intervention and its impact on health and social care resource use. This paper is concerned with the latter aim. METHODS: A cluster-randomised controlled trial was conducted involving day services for adults with ID in Scotland, England and Wales. Incremental costs of delivering the intervention and its impact on subsequent total health and social care package costs were calculated. Full data comparing costs between baseline and follow-up 10 months later were collected for 67 participants in the intervention arm and 62 participants in the control arm. Cost differences between the groups at follow-up, adjusted for baseline levels, were calculated using non-parametric bootstrapping controlling for clustering. RESULTS: The mean hourly excess cost of intervention over treatment as usual was £12.34. A mean adjusted cost difference of £22.46 per person per week in favour of the intervention group was found but this was not statistically significant. CONCLUSIONS: The baseline-adjusted cost difference at follow-up would result in a fairly immediate compensation for the excess costs of intervention, provided the difference is not a statistical artefact. Further research is needed to clarify the extent to which it might represent a real saving in service support costs.
Assuntos
Ira/fisiologia , Terapia Cognitivo-Comportamental/economia , Serviços de Saúde/economia , Deficiência Intelectual/economia , Deficiência Intelectual/terapia , Adulto , Inglaterra , Feminino , Seguimentos , Serviços de Saúde/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Escócia , País de GalesRESUMO
BACKGROUND: Previous research has demonstrated that people with mild intellectual disabilities (ID) have difficulty in 'weighing up' information, defined as integrating disparate items of information in order to reach a decision. However, this problem could be overcome by the use of a visual aid to decision making. In an earlier study, participants were taught to translate information about the pros and cons of different choices into a single evaluative dimension, by manipulating green (good) and red (bad) bars of varying lengths (corresponding to the value ascribed). Use of the visual calculator increased the consistency of performance (and decreased impulsive responding) in a temporal discounting task, and increased the amount of information that participants provided to justify their decisions in scenario-based financial decision-making tasks. METHODS: The present study examined some practical aspects of visual calculator training, using a pen-and-paper version of two temporal discounting tasks. Participants with mild ID were tested, individually and in a group setting, before and after training in the group setting, and 2 months later. RESULTS: (i) The visual aid improved temporal discounting performance using pen-and-paper presentation in a group setting as effectively as previously demonstrated using computer-based individual presentation. (ii) Following withdrawal of the aid, improvements in temporal discounting performance were maintained at 1 day post training, but lost following a 2-month hiatus; however, participants showed perfect retention, over 2 months, of how to use the aid. (iii) In addition to decreasing impulsivity in a hypothetical task, as previously demonstrated, use of the visual calculator also increased the ability of impulsive participants to wait in real time. CONCLUSION: The results suggest that the visual calculator has practical applicability to support decision making by people with mild ID in community settings.
Assuntos
Tomada de Decisões/fisiologia , Comportamento Impulsivo/fisiopatologia , Comportamento Impulsivo/reabilitação , Deficiência Intelectual/fisiopatologia , Deficiência Intelectual/reabilitação , Reforço por Recompensa , Adulto , Comportamento de Escolha/fisiologia , Feminino , Humanos , Masculino , Processos Mentais/fisiologia , Pessoa de Meia-Idade , Estimulação Luminosa/métodos , FotografaçãoRESUMO
BACKGROUND: Executive functioning (EF) is an important concept in cognitive psychology that has rarely been studied in people with intellectual disabilities (IDs). The aim of this study was to examine the validity of two test batteries and the structure of EF in this client group. METHODS: We administered the children's version of the Behavioural Assessment of the Dysexecutive Syndrome (BADS-C) and the Cambridge Executive Functioning Assessment (CEFA) for people with ID, to 40 participants who attended day centres for people with mild to moderate learning disabilities [mean full-scale intelligence quotient (IQ) = 59]. The BADS-C consists of six EF subtests while the CEFA contains eight EF (including two executive memory) subtests and four memory subtests. IQ and receptive language ability were also assessed. The results were subjected to principal components analysis, and regression analysis was used to examine the relationship of the ensuing factors to other cognitive variables. RESULTS: Scores on both sets of EF tests were only weakly related to receptive language ability, and even more weakly related to IQ. Scores on the BADS-C were substantially lower than predicted from the published norms for people in higher IQ ranges, and many participants scored zero on three of the six subtests. This potential floor effect was less evident with scores on the CEFA. Principal components analyses produced one usable factor for the BADS-C, and two factors for the CEFA that differed in both the extent of involvement of working memory and the predominant sensory modality. A combined analysis of the subtests retained from both analyses produced three factors that related uniquely to aspects of IQ and memory. CONCLUSIONS: The CEFA is suitable for use with people with mild to moderate learning disabilities, whereas the BADS-C is at the lower limit of usability with this client group. The lower-than-expected scores observed on the BADS-C may indicate that people known to learning disability services may be more impaired than people of comparable IQ not known to services. The structure of EF seen in people with IDs closely resembles a model of EF in the general population that has received a broad level of support.
Assuntos
Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/epidemiologia , Deficiência Intelectual/epidemiologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Índice de Gravidade de Doença , Adulto JovemRESUMO
BACKGROUND: An assessment of mental capacity includes an evaluation of the ability to 'weigh up' information, but how to do this is uncertain. We have previously used a laboratory decision-making task, temporal discounting, which involves a trade-off between the value and the delay of expected rewards. Participants with intellectual disabilities (ID) showed very little evidence of 'weighing up' of information: only a third of participants showed consistent temporal discounting performance, and when present, consistent performance was usually impulsive; and the ability to perform consistently was more strongly related to executive functioning than to IQ. The aim of the present study was to replicate these observations and extend them to a more realistic financial decision-making task. METHODS: We administered a temporal discounting task and a financial decision-making task, as well as tests of executive functioning and IQ, to 20 participants who attended day services for people with learning disabilities (mean Full-Scale IQ = 59), and to 10 staff members. RESULTS: Performance in both decision-making tasks was related more strongly to executive functioning than to IQ. In both tasks, decisions by service users were made largely on the basis of a single item of information: there was very little evidence in either task that information from two sources was being 'weighed'. CONCLUSIONS: The results suggest that difficulty in 'weighing up' information may be a general problem for people with ID, pointing to a need for psycho-educational remediation strategies to address this issue. The importance of executive functioning in decision-making by people with ID is not recognized in the legal test for mental capacity, which in practice includes a possibly irrelevant IQ criterion.
Assuntos
Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/epidemiologia , Administração Financeira , Deficiência Intelectual/epidemiologia , Resolução de Problemas , Adulto , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Índice de Gravidade de DoençaRESUMO
AIM: The Gudjonsson Suggestibility Scale (GSS) assesses suggestibility by asking respondents to recall a short story, followed by exposure to leading questions and pressure to change their responses. Suggestibility, as assessed by the GSS, appears to be elevated in people with intellectual disabilities (ID). This has been shown to reflect to some extent the fact that people with ID have poor recall of the story; however, there are discrepancies in this relationship. The aim of the present study was to investigate whether a closer match between memory and suggestibility would be found using a measure of recognition memory rather than free recall. METHOD: Three modifications to the procedure were presented to users of a learning disabilities day service. In all three experiments, a measure of forced-choice recognition memory was built into the suggestibility test. In experiments 1 and 2, the GSS was presented using either divided presentation (splitting the story into two halves, with memory and suggestibility tests after each half) or multiple presentation (the story was presented three times before presentation of the memory and suggestibility tests). Participants were tested twice, once with the standard version of the test and once with one of the modified versions. In experiment 3, an alternative suggestibility scale (ASS3) was created, based on real events in a learning disabilities day service. The ASS3 was presented to one group of participants who had been present at the events, and a second group who attended a different day service, to whom the events were unfamiliar. RESULTS: As observed previously, suggestibility was not closely related to free recall performance: recall was increased equally by all three manipulations, but they produced, respectively, no effect, a modest effect and a large effect on suggestibility. However, the effects on suggestibility were closely related to performance on the forced-choice recognition memory task: divided presentation of the GSS2 had no effect on either of these measures; multiple presentation of the GSS2 produced a modest increase in recognition memory and a modest decrease in suggestibility; and replacing the GSS with the ASS3 produced a large increase in recognition memory and a large decrease in suggestibility. IMPLICATIONS: The results support earlier findings that the GSS is likely to overestimate how suggestible a person will be in relation to a personally significant event. This reflects poor recognition memory for the material being tested, rather than increased suggestibility per se. People with ID may in fact be relatively non-suggestible for well-remembered events, which would include personally significant events, particularly those witnessed recently.
Assuntos
Deficiência Intelectual/psicologia , Memória , Testes Psicológicos , Reconhecimento Psicológico , Sugestão , Adulto , Comportamento de Escolha , Feminino , Humanos , Masculino , Rememoração Mental , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Análise e Desempenho de TarefasRESUMO
The most familiar usage of animal models of depression is as antidepressant screening tests. Paul Willner reviews their usage in a different context--as simulations of depression. The behavioural features of animal models of depression are compared with clinical symptomatology, and the contribution of animal models to understanding the following aspects of depression are reviewed: sources of population variability, natural history, psychological aspects, symptomatology and mechanisms of antidepressant action. Finally, the role of animal models of depression is considered as a critical interface between basic behavioural neuroscience and the clinic.
Assuntos
Comportamento Animal/fisiologia , Depressão/psicologia , Modelos Animais de Doenças , Animais , Depressão/fisiopatologia , HumanosRESUMO
BACKGROUND: Pancreatic trauma in children is relatively uncommon, but carries high morbidity and mortality rates when diagnosis is delayed. Preoperative diagnosis of pancreatic lesion might be difficult, especially in the case of isolated injury. METHODOLOGY: Authors analyse seven cases of pancreatic trauma in childhood. In three cases surgical intervention was required due to pancreatic transection with main pancreatic duct rupture. The injuries of the 5-10 years old male patients were diagnosed and operated on within 24 hours. RESULTS: In two cases distal resection were performed with splenic preservation. In one case--where the operation was performed within 8 hours--preservation of the distal pancreas was also achieved by distal pancreatogastrostomy. The postoperative period was uneventful in all cases. Impaired glucose metabolism was not found in the operated cases during the follow up. CONCLUSIONS: Authors emphasise the importance of CT scan and the responsibility of the first attending physician regarding both diagnosis and correct surgical management.
Assuntos
Traumatismos Abdominais/complicações , Traumatismos Abdominais/cirurgia , Pâncreas/lesões , Pâncreas/cirurgia , Ferimentos não Penetrantes/complicações , Ferimentos não Penetrantes/cirurgia , Traumatismos Abdominais/diagnóstico , Criança , Pré-Escolar , Diagnóstico Diferencial , Humanos , Tomografia Computadorizada por Raios X , Ferimentos não Penetrantes/diagnósticoRESUMO
Previous studies have demonstrated that chronic exposure of rats to a melange of ultra-mild stressors causes an antidepressant-reversible decrease in the intake of palatable weak sucrose solutions, as well as other evidence of insensitivity to rewards. In the present study, we analyzed some of the behavioral requirements for the suppression of consummatory behaviour by chronic mild stress. Rats exposed to our standard chronic mild stress protocol and tested following 20 h food and water deprivation showed a decrease in intake of 1% sucrose, but not of water or chow. The effect on sucrose intake was also present, but smaller, in non-deprived animals, and wa seen in both singly- and pair-housed animals. Experiments designed to identify the crucial elements of the stress procedure showed that one element, paired housing (in animals normally housed singly) was particularly potent. However, no one element was either necessary to cause the decrease in sucrose intake, or sufficient to maintain the impairment for longer than 4 weeks: Variety and frequency of microstressors appeared to be the essential features of procedures causing a prolonged anhedonia.
Assuntos
Ingestão de Líquidos/efeitos dos fármacos , Estresse Psicológico/psicologia , Sacarose/farmacologia , Glândulas Suprarrenais/efeitos dos fármacos , Animais , Ingestão de Alimentos/efeitos dos fármacos , Habituação Psicofisiológica , Masculino , Tamanho do Órgão/efeitos dos fármacos , RatosRESUMO
Chronic sequential administration of a variety of mild stressors causes a decrease in responsiveness to rewards in rats, which is reversed by chronic administration of antidepressant drugs. This paper reviews the validity of chronic mild stress-induced anhedonia as an animal model of depression, and the evidence that changes in hedonic responsiveness in this model are mediated by changes in the sensitivity of dopamine D2 receptors in the nucleus accumbens. The review opens with an analysis of the design features of animal models of depression, and ends with a brief account of other animal models of anhedonia.
Assuntos
Transtorno Depressivo/psicologia , Recompensa , Estresse Psicológico/psicologia , Animais , Modelos Animais de DoençasRESUMO
Consumption of a palatable wet mash was examined in rats subjected chronically (4-10 weeks) to unpredictable mild stress. Intake of mash containing 0, 10%, or 20% additional sucrose was normal in stressed animals. In control animals, the addition of 30% or 40% sucrose caused a decrease in the quantity of mash consumed, but increased the rate of eating. Both the increase in eating rate and the decrease in intake, at high sucrose concentration, were markedly attenuated in stressed animals (which therefore had higher intakes of very sweet mash and lower rates of eating, relative to control animals). Like chronic mild stress, the dopamine receptor antagonist pimozide (0.2 mg/kg) also increased the intake of a wet mash with 30% added sucrose, while decreasing the rate of consumption. Stressed animals were relatively insensitive to pimozide, though there were significant additive effects on duration of eating (increased) and on postprandial resting (suppressed). The failure of stressed animals to adapt their intake to increases in sweetness, and the similarities between the effects of chronic mild stress and acute pimozide, are compatible with the hypothesis that animals exposed to chronic mild stress are anhedonic.
Assuntos
Pimozida/farmacologia , Estresse Psicológico/psicologia , Paladar/fisiologia , Animais , Ingestão de Alimentos/efeitos dos fármacos , Masculino , Ratos , Paladar/efeitos dos fármacosRESUMO
Rats, subjected chronically (10-12 weeks) to a variety of mild, unpredictable stressors, showed a decrease in their consumption of weak sucrose solutions; normal behavior was restored by chronic (5-9 weeks) treatment with the tricyclic antidepressant imipramine. Acute administration of the dopamine receptor antagonist pimozide or the specific dopamine D2 receptor antagonist raclopride had no effect in nonstressed animals and in vehicle-treated stressed animals, but both drugs selectively reversed the improvement of performance in imipramine-treated stressed animals. The 5HT antagonist metergoline increased sucrose consumption in all groups. The data suggest that the mechanism of action of imipramine in this model is an increase in functional activity at dopamine (DA) synapses.
Assuntos
Nível de Alerta/efeitos dos fármacos , Transtorno Depressivo/tratamento farmacológico , Imipramina/administração & dosagem , Receptores Dopaminérgicos/efeitos dos fármacos , Animais , Comportamento Apetitivo/efeitos dos fármacos , Ingestão de Líquidos/efeitos dos fármacos , Masculino , Metergolina/farmacologia , Pimozida/farmacologia , Racloprida , Ratos , Ratos Endogâmicos , Salicilamidas/farmacologia , Paladar/efeitos dos fármacosRESUMO
Chronic exposure to mild unpredictable stress (CMS) has previously been found to cause an antidepressant-reversible decrease in the consumption of palatable sweet solutions. There is evidence that the effect of antidepressants in this model is mediated by an increase in transmission at dopamine (DA) synpases. The present study investigated whether another treatment known to increase the functional responsiveness of DA systems, intermittent administration of DA agonists, would have antidepressant-like effects. In three experiments in rats, CMS-induced decreases in sucrose consumption were reversed by three to four twice-weekly injections of quinpirole (100-200 micrograms/kg) or bromocriptine (2.5 mg/kg). The effects lasted for several weeks, and when they waned, could be reinstated by a single additional injection of quinpirole. As with tricyclic antidepressants, the effect of quinpirole was reversed by raclopride, administered acutely immediately prior to a sucrose consumption test; there were no changes in sucrose intake in nonstressed control animals. The results suggest that intermittent administration of DA agonists merits investigation as a novel strategy for the treatment of depression.
Assuntos
Nível de Alerta/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Bromocriptina/uso terapêutico , Transtorno Depressivo/tratamento farmacológico , Dopaminérgicos/uso terapêutico , Ergolinas/uso terapêutico , Desamparo Aprendido , Receptores Dopaminérgicos/efeitos dos fármacos , Animais , Transtorno Depressivo/psicologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Ingestão de Líquidos/efeitos dos fármacos , Masculino , Motivação , Quimpirol , Ratos , Receptores de Dopamina D2 , Receptores de Dopamina D3 , Paladar/efeitos dos fármacosRESUMO
Chronic exposure to mild unpredictable stress causes subsensitivity to rewards (anhedonia). These effects are reversible by chronic treatment with antidepressant drugs, and have been proposed as an animal model of depression. In the present study, sleep architecture, particularly the rapid eye movement (REM) component, was mapped in rats following exposure to chronic mild stress. The study used a unique large scale automated sleep system to record and analyze the sleep signals from 32 rats simultaneously. The effects of stress on sleep were maximal following 21 days of stress, at which time the stressed animals demonstrated decreases in active waking and deep sleep, and disruptions of REM sleep. The changes in REM sleep included increases in the duration of and transitions into REM sleep over the sleep part of the sleep-wake cycle, and most importantly, a reduced latency to the onset of the first REM period. These sleep abnormalities, and in particular the decrease in REM latency, are consistent with those reported in endogenous depression. The results provide further support for the validity of the chronic mild stress paradigm as an animal model to study the mechanisms underlying endogenous depression.
Assuntos
Eletroencefalografia , Transtornos do Sono-Vigília/diagnóstico , Sono REM , Estresse Psicológico/diagnóstico , Animais , Comportamento Animal , Masculino , Modelos Biológicos , Ratos , Transtornos do Sono-Vigília/etiologia , Estresse Psicológico/psicologia , VigíliaRESUMO
This paper evaluates the validity, reliability and utility of the chronic mild stress (CMS) model of depression. In the CMS model, rats or mice are exposed sequentially, over a period of weeks, to a variety of mild stressors, and the measure most commonly used to track the effects is a decrease in consumption of a palatable sweet solution. The model has good predictive validity (behavioural changes are reversed by chronic treatment with a wide variety of antidepressants), face validity (almost all demonstrable symptoms of depression have been demonstrated), and construct validity (CMS causes a generalized decrease in responsiveness to rewards, comparable to anhedonia, the core symptom of the melancholic subtype of major depressive disorder). Overall, the CMS procedure appears to be at least as valid as any other animal model of depression. The procedure does, however, have two major drawbacks. One is the practical difficulty of carrying out CMS experiments, which are labour intensive, demanding of space, and of long duration. The other is that, while the procedure operates reliably in many laboratories, it can be difficult to establish, for reasons which remain unclear. However, once established, the CMS model can be used to study problems that are extremely difficult to address by other means.
Assuntos
Transtorno Depressivo/fisiopatologia , Estresse Psicológico/fisiopatologia , Animais , Doença Crônica/psicologia , Transtorno Depressivo/etiologia , Transtorno Depressivo/psicologia , Modelos Animais de Doenças , Camundongos , Ratos , Reprodutibilidade dos Testes , Estresse Psicológico/complicações , Estresse Psicológico/psicologiaRESUMO
The effects of acute and chronic antidepressant treatment on various aspects of 5-HT neurotransmission are reviewed, in order to assess the net effect of antidepressants on transmission across 5-HT synapses. Events considered include presynaptic effects of antidepressants (on autoreceptor function, uptake and turnover) and effects on postsynaptic receptor function (assessed by electrophysiological, neuroendocrine, behavioural, and receptor binding methods). Acute antidepressant treatment has variable effects: transmission may be enhanced, unchanged or reduced, depending mainly upon the relative contributions of 5-HT uptake blockade and 5-HT receptor antagonism. However, on chronic administration, most antidepressants appear to enhance 5-HT transmission. This effect is clearest in the case of ECS, which has little effect on 5-HT turnover, but reduces uptake and increases postsynaptic receptor function. MAOIs may be an exception: there is little evidence that MAOIs enhance 5-HT transmission following chronic treatment. Most other antidepressant drugs, including some which are powerful receptor antagonists on acute administration, reduce 5-HT receptor function briefly, but enhance receptor function if several hours elapse between the final injection and testing. Zimelidine has little effect on postsynaptic receptor function, but enhances 5-HT transmission by its powerful blockade of 5-HT uptake. Chronic treatment with antidepressant drugs has usually been found to reduce binding to 5-HT2 receptors; it is difficult to reconcile these observations with the functional studies. In general, with the possible exception of MAOIs, chronic administration of antidepressants may enhance 5-HT transmission by both pre- and post-synaptic effects, and the relative contributions vary. This conclusion supports the classical "indoleamine hypothesis of depression" rather than the more recent "hypersensitive serotonin receptor" theory.
Assuntos
Antidepressivos/farmacologia , Serotonina/fisiologia , Transmissão Sináptica/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Transtorno Depressivo/fisiopatologia , Modelos Animais de Doenças , Eletrochoque , Humanos , Ácido Hidroxi-Indolacético/líquido cefalorraquidiano , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Inibidores da Monoaminoxidase/farmacologia , Bulbo Olfatório/cirurgia , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Ratos , Receptores de Serotonina/efeitos dos fármacos , Serotonina/metabolismo , Zimeldina/farmacologiaRESUMO
Eighteen animal models of depression are reviewed in relation to three sets of validating criteria. Of the 18 models, five could only be assessed for predictive validity, seven could be assessed for predictive and face validity, and six could potentially have predictive, face and construct validity. Some traditional models (reserpine reversal, amphetamine potentiation) are rejected as invalid; the models with the highest overall validity are the intracranial self-stimulation, chronic stress and learned helplessness models in rats, and the primate separation model.
Assuntos
Comportamento Animal/fisiologia , Transtorno Depressivo/fisiopatologia , Modelos Animais de Doenças , 5-Hidroxitriptofano/farmacologia , Anfetamina/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Ritmo Circadiano , Di-Hidroxifenilalanina/farmacologia , Sinergismo Farmacológico , Desamparo Aprendido , Humanos , Excitação Neurológica/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Bulbo Olfatório/fisiologia , Comportamento Predatório/efeitos dos fármacos , Ratos , Reserpina/antagonistas & inibidores , Autoestimulação/fisiologia , Isolamento Social , Estresse Psicológico/fisiopatologia , Ioimbina/farmacologiaRESUMO
Effects of the dopamine D2 receptor antagonist sulpiride and the D1 antagonist SCH-23390 were examined, in rats, in two-bottle preference tests (sucrose versus water) and in single-bottle tests, at different sucrose concentrations. Both drugs decreased sucrose intake in single bottle tests, at low sucrose concentrations, but had no effect at high concentrations; reducing drive level had exactly the opposite pattern of effects. In two-bottle tests, both drugs reduced preference for the weakest sucrose concentration (0.7%) but increased preference for the strongest concentration (34%). The effects of antagonizing either subtype of DA receptor appear to be similar to those of reducing the concentration of sucrose.
Assuntos
Benzazepinas/farmacologia , Antagonistas de Dopamina , Preferências Alimentares/efeitos dos fármacos , Receptores Dopaminérgicos/efeitos dos fármacos , Sacarose/administração & dosagem , Sulpirida/farmacologia , Animais , Ingestão de Líquidos/efeitos dos fármacos , Masculino , RatosRESUMO
Low doses of 8-OH-DPAT (62.5-250 micrograms/kg) were reinforcing in the place preference conditioning procedure, while a higher dose (1 mg/kg) supported a conditioned place aversion. The 5-HT synthesis inhibitor PCPA, and the DA antagonists pimozide and sulpiride, had no effect when administered alone, but abolished the 8-OH-DPAT-induced place preference. However, neither PCPA nor pimozide altered the 8-OH-DPAT-induced place aversion. The results are consistent with other evidence showing that 8-OH-DPAT acts through different mechanisms at low and high doses, and support the hypothesis that low doses of 8-OH-DPAT act through 5-HT neurons to disinhibit dopaminergic activity.
Assuntos
Aprendizagem da Esquiva/efeitos dos fármacos , Condicionamento Operante/efeitos dos fármacos , Antagonistas de Dopamina , Antagonistas da Serotonina/farmacologia , Tetra-Hidronaftalenos/farmacologia , 8-Hidroxi-2-(di-n-propilamino)tetralina , Animais , Fenclonina/farmacologia , Masculino , Pimozida/farmacologia , Ratos , Sulpirida/farmacologia , Tetra-Hidronaftalenos/antagonistas & inibidoresRESUMO
The administration of trycyclic antidepressants followed by reserpine-like drugs elicits a pattern of stereotyped locomotor activity. Using desmethylimipramine (DMI) followed by tetrabenazine (TBZ), activity could be reliably elicited only in young rats, and only by using very high doses of TBZ. The latency of onset of activity was up to 5 h. Animals rendered active by DMI-TBZ failed to perform a well-established operant task. The activity syndrome was apparently unaffected by pre- or posttreatment with the dopamine antagonists spiroperidol or primozide, but partial antagonism was obtained with the noradrenaline antagonists phentolamine and phenoxybenzamine. The findings are discussed in relation to the mechanism of action of the effect and its relevance to the clinical action of tricyclic antidepressants.