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Biomedical subjects

A Tobeña

Publications and source records attributed to A Tobeña.

51 records · Page 3Linked to original sources
PubMed1989

Onset of panic disorder with agoraphobia. Toward an integrated model.

Of 57 patients with panic disorder with agoraphobia, more had their first panic in late spring and summer than in fall and winter, and in warm weather than in cold weather. In the month before the first panic 52% of the patients had prodromal depression or anxiety. Agoraphobic avoidance preceded the first panic in 23%, began within days after the first panic in 32% (without prodromal anxiety or depression in only 20%), and after more than one panic (1 week to 11 years later) in 41%. The site of the first panic was from the agoraphobic cluster (public places) in 81%, at work or school in 11%, and inside the home in 8%. Thirty-eight percent of patients were with a familiar adult at the time. Many features of the syndrome can be explained by an integrated model with several interacting factors contributing in varying degrees to the different routes by which it develops. To the learning and biological factors already suggested we add an evolutionary factor to explain why most first panics occur outside the home and mainly in public places. Certain extraterritorial cues constituting an agoraphobic cluster seem to be prepotent and prepared triggers or modifiers of fear during stress.

Agoraphobia↗
PubMed1989

Differential recovery in naming in bilingual aphasics.

Language performance in a sample of 30 Catalan-Spanish bilingual aphasics was studied using three nominal tasks (naming, pointing, and translation). We compared performance between the two languages before and after therapy and also compared the improvements made in each language. Therapy was carried out in only one language, namely Catalan. Significant differences between the two languages were initially seen in the naming and translation tasks while after treatment significant differences were observed in the naming and pointing tasks. Analysis of covariance was carried out to control the influence of the initial performance on improvements. Performance in the naming task improved more in the treated language (Catalan) than in the nontreated language. We conclude that both differential impairment and recovery of languages in bilingual aphasics is seen not only in rare cases but also in studies of larger samples.

Adult↗
PubMed1988

Sodium valproate reduces immobility in the behavioral 'despair' test in rats.

The present study was conducted to investigate whether sodium valproate could affect immobility in the 'behavioral despair' test in rats. Acute (one injection), subacute (three injections) and chronic treatment with sodium valproate reduced the immobility time in this test, whereas a stimulation of motor activity in the open-field test was not observed with the same drug treatments. The anti-immobility activity of valproate was partially counteracted by the administration of bicuculline (2 mg/kg) or picrotoxin (1.4 mg/kg) before the immobility test. The data agree with previous findings from several animal models of depression of an antidepressant-like activity of GABA mimetics or agents which stimulate GABAergic function.

Animals↗
PubMed1988

The anxiolytic action of benzodiazepines is not present in handling-habituated rats.

The acquisition of two-way shuttle avoidance (40 first trials) was used to test the anxiolytic activity of diazepam (2 and 4 mg/kg) and alprazolam (1.25 mg/kg) vs. vehicle, IP, in rats. These rats had received three different previous treatments: acute, acute with previous handling habituation for 15 days, and handling habituation combined with chronic treatment for 15 days. Results of the acute treatment showed a comparable anxiolytic action of diazepam and alprazolam, reflected by an improvement in avoidance acquisition. After handling habituation, no effect on shuttle box acquisition was obtained in rats acutely treated with diazepam, whereas the alprazolam-treated group showed a significantly impaired avoidance performance. When handling habituation was combined with chronic benzodiazepine treatment, the drugs' anxiolytic action persisted although there was a complete disappearance of their sedative effects. These behavioral results are discussed in relation to the emotional changes induced by the procedures of handling. They are tentatively linked with possible changes in the functionality of GABA neurotransmission, possibly at the level of the GABA-benzodiazepine receptor which some studies have found associated to handling habituation.

Alprazolam↗
PubMed1987

Neuropsychological performance in opiate addicts after rapid detoxification.

Neuropsychological performance before and after a rapid (1 week) detoxification treatment, was studied in heroin addicts. Ninety-three opioid dependents (DSM-III) were evaluated with a brief test battery assessing attention, memory and verbal fluency performance prior to their admission to a Detoxification Unit. Significant differences were noted between the addicts' performance and a group of 30 comparable normals, whose intellectual ability was similar. At re-evaluation addicts showed improvement in most measures, including general clinical status. Moreover, no differences between the sample of detoxificated addicts and controls on measures of neuropsychological performance were then detected. No relationship was found between psychopathological symptoms and neuropsychological functioning after the pharmacological detoxification of addicts. The length of addiction or drug consumption were not predictive of neuropsychological impairment in the present sample of heroin addicts.

Adolescent↗
PubMedDate not supplied

Flumazenil prevents the anxiolytic effects of diazepam, alprazolam and adinazolam on the early acquisition of two-way active avoidance.

The effects of diazepam (DZ, 4 mg/kg), alprazolam (ALP, 1.25 mg/kg) and adinazolam (ADIN, 6 mg/kg), as well as their interaction with the benzodiazepine receptor antagonist flumazenil (Ro15-1788), were studied on the early acquisition of two-way active (shuttlebox) avoidance in male Sprague-Dawley rats. The three benzodiazepines increased shuttlebox avoidance acquisition, and their effects were prevented (antagonized) by flumazenil (10 mg/kg). The present results indicate that central benzodiazepine (BZ) receptors are involved in the anxiolytic effects of diazepam and triazolobenzodiazepines on the early acquisition of two-way active avoidance.

Alprazolam↗
PubMedDate not supplied

Postnatal handling reduces anxiety as measured by emotionality rating and hyponeophagia tests in female rats.

The present studies evaluated the short- and long-lasting effects of postnatal handling (administered during the first 21 days of life) on the emotional behavior of female Sprague-Dawley rats. The performance of postnatally handled (H) and control nonhandled (NH) animals was compared in two different situations: an emotionality rating (ER) test (when they were 40 days or 4 months old), and a hyponeophagia (neophobia) test of anxiety, at the age of 4 months. The results showed that postnatal handling induced both short-term and long-term reductions of spontaneous emotional reactivity in the ER test, although the effects on some measures disappeared in 4-month-old rats. Postnatal handling also induced enduring decreases of anxiety as measured by the hyponeophagia test. None of the observed effects were attributable to changes in basal locomotor activity. ER measures were significantly related to hyponeophagia, because animals showing the highest emotionality scores in the ER test (preferentially NH animals) were those that showed the highest eating latencies and spent less time eating in the neophobic situation (i.e., hyponeophagia test).

Aging↗
PubMedDate not supplied

Anxiolytic profiles of alprazolam and ethanol in the elevated plus-maze test and the early acquisition of shuttlebox avoidance.

Rats pretreated either with the anxiolytic triazolobenzodiazepine alprazolam (0.75 and 1.75 mg kg-1 i.p.) or ethanol (1, 2, 3 and 4 g kg-1 p.o.) were tested in both the elevated plus-maze and the early acquisition of shuttlebox avoidance. Both substances induced overall anxiolytic effects in the plus-maze, with the 0.75 mg kg-1 being the most effective alprazolam dose and 1-3 g kg-1 being the most effective ethanol doses. Both drugs were also anxiolytic in the shuttlebox, since 1.75 mg kg-1 alprazolam and 2-3 g kg-1 ethanol improved acquisition of the task. Correlational and factor analysis showed that behaviour in the open arms of the plus-maze and efficiency in shuttlebox avoidance acquisition are positively associated, thus providing further support to the contention that the early acquisition of shuttlebox avoidance is an animal model of anxiety.

Alprazolam↗
PubMedDate not supplied

Environmental enrichment and postnatal handling prevent spatial learning deficits in aged hypoemotional (Roman high-avoidance) and hyperemotional (Roman low-avoidance) rats.

The present study investigated the enduring effects of postnatal handling (administered during the first 21 days of life), and environmental enrichment (for a period of 6 months starting 3 weeks after weaning) on spatial learning in 24-month-old hypoemotional (Roman high-avoidance, RHA/Verh) and hyperemotional (Roman low-avoidance, RLA/Verh) rats. Two groups of 5-month-old rats from both lines were also included in the experiment as young controls. The Roman lines performed differently in the Morris water maze: Path lengths of RLA/Verh rats were shorter and they swam at lower speed than RHA/Verh rats, showing quicker and more efficient learning overall. Postnatal handling improved learning mainly in RHA/Verh rats, whereas environmental enrichment was able to prevent the deficits shown by aged controls of both lines. Young, enriched, and handled plus enriched animals exhibited better performance than impaired aged controls, to the point that aged enriched and handled plus enriched animals did not differ from young controls. Thus, besides indicating that RLA/Verh rats are better learners than RHA/Verh rats in the Morris water maze, this study demonstrates that environmental enrichment prevents the cognitive loss associated with aging, over the long term. Finally, the positive effects obtained with postnatal handling were dependent on the rat line.

Aging↗
PubMedDate not supplied

Imipramine and desipramine decrease the GABA-stimulated chloride uptake, and antigabaergic agents enhance their action in the forced swimming test in rats.

The present study reports that long-term (18 days) administration of imipramine (IMI, 20 mg/kg) or desipramine (DMI, 15 mg/kg) produced a significant decrease in the GABA-stimulated 36Cl- uptake into membrane vesicles from the cerebral cortex of rats (experiment 1). Experiments 2A, B show that anti-immobility effects of DMI and IMI (subacute treatment) in the forced swimming test are enhanced when a single subconvulsant injection of picrotoxin or pentylenetetrazol is administered to the animals concurrently to the last antidepressant injection. These results are discussed in relation with a current GABAergic hypothesis of depression and antidepressant drug action.

Animals↗
PubMedDate not supplied

[Latent inhibition threshold in Roman high-avoidance rats: a psychogenetic model of abnormalities in attentional filter?].

INTRODUCTION: Basic research devoted to the study of the psychobiological anomalies of schizophrenia, as well as of its treatments, has used animal models in which some psychotic-like symptoms are induced by administration of psychostimulant drugs. There is, however, a growing necessity of having animal models presenting better construct validity, i.e., animal lines spontaneously showing phenotypes associated to the psychotic spectrum (for instance, enhanced sensitivity to psychostimulants, or cognitive and attentional anomalies characteristic of schizophrenic disorders). Several lines of evidence suggest that the RHA (Roman high-avoidance) rat strain presents a neurobehavioral profile which is consistent with such goals. METHODS: RHA rats were compared to Sprague-Dawley (SD) rats (as a standard control strain) for the expression of latent inhibition (in a 100-trial session of two-way active avoidance) under threshold conditions (i.e., only 15 preexposures to the conditioned stimulus were administered). RESULTS: Under such experimental conditions SD rats showed significant latent inhibition of the two-way active avoidance response (both during the first 50 trials and in the whole 100-trial session), while that attentional phenomenon did not appear in the RHA strain. CONCLUSIONS: The experimental results obtained here indicate that RHA rats display a deficit of latent inhibition at threshold conditions, an information processing (or attentional) anomaly which typically appears in schizophrenic patients. It is proposed that RHA rats might be an useful animal model for the study of vulnerability to some schizophrenic symptoms. This conclusion is supported by data that indicate that latent inhibition deficits are a characteristic attentional abnormality of these diseases.

Animals↗