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F Boix

Publications and source records attributed to F Boix.

11 recordsLinked to original sources
PubMed1992

The C-terminal fragment of substance P enhances dopamine release in nucleus accumbens but not in neostriatum in freely moving rats.

The in vivo microdialysis technique was used to study the effects of carboxyl or amino terminal sequences of substance P on the extracellular concentrations of dopamine, its metabolites dihydroxyphenylacetic acid and homovanillic acid, as well as on 5-hydroxyindoleacetic acid, in neostriatum and nucleus accumbens of freely moving rats. The i.p. administration of 37 nmol/kg of the substance P C-terminal heptapeptide analog [pGlu5, MePhe8, Sar9]SP5-11 (DiMe-C7) caused an increase in extracellular dopamine concentrations in nucleus accumbens but not in neostriatum. The administration of the equimolar dose of the heptapeptide N-terminal fragment substance P 1-7 (SP1-7) did not have an effect in either structure. No changes were observed in the extracellular concentrations of the metabolites after the administration of either substance. These results are discussed with respect to the reinforcing effects of substance P and its C-terminal sequence, which may be mediated via dopamine release in the nucleus accumbens.

Animals↗
PubMed1992

Effects of substance P on extracellular dopamine in neostriatum and nucleus accumbens.

Microdialysis was used to monitor changes in dopamine release in the neostriatum and nucleus accumbens after peripheral administration of substance P in freely moving rats. Substance P in a dose of 50 micrograms/kg produced a steady moderate increase in dopamine levels in the neostriatum, which persisted for at least 5 h. In contrast, a dose of 250 micrograms/kg caused an acute increase in dopamine levels in the nucleus accumbens, which lasted about 2 h. These data suggest that the peripheral administration of substance P can influence dopamine release in mesolimbic and mesostriatal terminals.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1991

Lateralized changes in behavior and striatal dopamine release following unilateral tactile stimulation of the perioral region: a microdialysis study.

Intracranial microdialysis was used to measure dopamine (DA) release in the ventrolateral neostriatum of freely moving rats before and after unilateral tactile stimulation was applied to the orofacial region. Several behavioral parameters which have been linked to changes in nigrostriatal DA transmission (scanning, or snout contact with the walls of the observation chamber, turning and locomotion) were measured as well. Orofacial stimulation was followed by an asymmetrical increase in DA release with concentrations of transmitter higher in the neostriatum ipsilateral to the side of stimulation. Asymmetrical scanning behavior was observed during the time period when DA release was asymmetric, with rats favoring use of the side of the face contralateral to increased DA release. Increases in the DA metabolites DOPAC and HVA were found in the striatum ipsilateral to stimulation, but were delayed 40 min following the increase in DA.

Animals↗
PubMed1991

The early acquisition of two-way (shuttle-box) avoidance as an anxiety-mediated behavior: psychopharmacological validation.

Several lines of evidence have established that performance during the initial steps of acquisition on a shuttle-box avoidance task is an anxiety-mediated behavior (i.e., the differences between strains selectivity bred for emotionality; the effects of postnatal handling; the course of the corticosterone response and behavioral measures of fear during acquisition). The present study was carried out to add pharmacological evidence to that view by testing the action of anxiogenic and anxiolytic drugs. Single 40-trial sessions with mild shocks (0.4 mA-0.6 mA) were used. In the first experiments the action of sodium pentobarbital (1.25, 2.5 and 5 mg/kg) and three benzodiazepines (diazepam, 2 and 4 mg/kg; alprazolam, 1, 1.25 and 1.5 mg/kg and adinazolam, 1, 2, 4 and 6 mg/kg) were tested. The last two experiments tested a possible proanxiety action of Ro 15-4513 (2, 5 and 10 mg/kg) and FG 7142 (5, 10 and 15 mg/kg), two partial inverse agonists of benzodiazepine receptors, which previous data had suggested to be anxiogenic. The results showed that the measure of acquisition of a two-way active avoidance is a sensitive mean for detecting either anxiolytic or anxiogenic effects of drugs, independently of their effects on locomotor activity, thus suggesting that such test could be a valid model of anxiety in animals.

Animals↗
PubMed1991

Effects of different handling-stimulation procedures and benzodiazepines on two-way active avoidance acquisition in rats.

The acquisition of two-way active (shuttlebox) avoidance involves a conflict situation which can be used as an animal model of anxiety, since it is sensitive to manipulations of the animal's emotivity/reactivity. The results from the present study (experiment 1) add relevant support to that proposal, since diazepam (2 and 4 mg/kg) and the triazolobenzodiazepine alprazolam (1, 1.25 and 1.5 mg/kg) significantly improved avoidance performance in shuttlebox acquisition in rats in agreement with previous data. In another study (experiment 2), a mild stressful (10-day) handling procedure (i.e. handling which tends to increase the emotional reactivity of the animals, as showed in experiment 3) was found to affect such behaviour in an opposite direction to that of the two benzodiazepines. Conversely, when an habituating handling procedure (i.e. handling which leads to less reactive animals; experiment 3) was used, the acquisition of shuttlebox avoidance was improved (experiment 4). The results are discussed in relation with previous data showing that the particular parameters used in the exposure to stressful stimuli may lead to either sensitization or habituation of anxious responses.

Alprazolam↗
PubMed1990

Picrotoxin changes the effects of imipramine and desipramine in rats in the forced swimming test.

The aim was to find whether the chloride channel blocker, picrotoxin, at subconvulsant doses could affect the activity of imipramine or desipramine in the 'forced swimming' test with rats. It was found that picrotoxin enhanced the anti-immobility effects of imipramine and desipramine whereas open field activity remained unaffected or was even decreased by the same treatments. The results seem consistent with recent reports showing direct interactions between several antidepressant drugs and the GABAA receptor/benzodiazepine receptor/chloride ionophore complex (GABAA/benzodiazepine/Cl complex). The results also conform with the hypothesis that a reduction in the functionality of this complex could be related to the clinical effects of antidepressant drugs.

Animals↗
PubMed1990

Handling-habituation prevents the effects of diazepam and alprazolam on brain serotonin levels in rats.

In two different experiments, serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) levels were measured in rats, using HPLC with electrochemical detection, in 3 brain regions (hippocampus, cerebral cortex and hypothalamus) after acute i.p. treatment with diazepam (4 mg/kg), alprazolam (1.25 mg/kg) or vehicle. In the first experiment, rats received the acute treatment 30 min before they were sacrificed. In the second, the animals were previously habituated to handling (involving the maneuvers of injecting and sacrificing at the guillotine) daily for 15 days, before the acute administration of the drugs. Results of the acute treatment alone showed a significant increase in 5-HT levels in hippocampus and cerebral cortex, and a decrease in hypothalamus, but not differences in 5-HIAA levels, for the diazepam- and alprazolam-treated groups. After handling-habituation, no effect in the monoamine or metabolite levels appeared when the rats were treated with diazepam or alprazolam. The results are discussed in relation to the emotional changes induced by the handling procedure, and for possible connections between the mechanisms of action of handling-habituation and benzodiazepine treatments at CNS level.

Alprazolam↗
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↗
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↗