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Biomedical subjects

W Kostowski

Publications and source records attributed to W Kostowski.

At least 199 records · Page 11Linked to original sources

Effects of lesions of monoaminergic system in the brain on the hypotensive effects of clonidine in rats.

Bilateral lesions of the locus coeruleus markedly reduced hypotensive effects of clonidine in rats. Lesions shifted laterally did not evoke any significant change of the hypotensive effects of clonidine or bradycardia induced by it. Lesions of the ventral and dorsal noradrenergic tract at the midbrain level and lesions of the midbrain raphe area failed to change hypotensive response to clonidine.

Animals↗

Effects of stimulation of raphe nuclei on ponto-geniculo-occipital syndrome evoked by reserpine in cats.

Stimulation of the dorsal raphe nucleus in the cat caused inhibition of ponto-geniculo-occipital waves induced by reserpine. Electrical stimuli with frequency of 10/sec. caused stronger effect than low-frequency impulses. The results indicate the PGO generating mechanisms (related probably with noradrenergic neurons of the nucleus locus coeruleus is suppressed by raphe nuclei.

Animals↗

Hexobarbital sleeping time in the rat: effects of isolation and lesions of the locus coeruleus.

Hexobarbital sleeping time was observed in isolated and nonisolated rats with lesioned locus coeruleus (LC). Isolated animals were divided into 2 groups: aggressive (killers) and indifferent (nonkillers). Each group included rats with no lesion, with sham lesion and with LC lesion. Hexobarbital sleeping time was prolonged in nonisolated male, but not female, rats with lesioned LC (7 and 14 days after the lesion). This effect was not observed in animals previously isolated for 3 weeks. These results suggest that the LC plays an important role in the mechanisms of barbiturate sleep, but this effect may be related to the emotionality of animals.

Aggression↗

Alcohol intake and brain [3H]muscimol binding sites in alcohol-preferring and non-preferring rats.

The present study has employed in vitro autoradiography to determine the distribution and density of [3H]muscimol binding sites in the brains of alcohol high-preferring line of rats (WHP) and alcohol low-preferring line of rats (WLP). While the density of [3H]muscimol binding was found to be similar in the frontal cortex, caudate-putamen, nucleus accumbens, lateral and medial septum, the density of [3H]muscimol binding was lower in cingulate cortex of alcohol low-preferring rats as compared to alcohol high preferring rats. Moreover, the density of muscimol binding sites within this area was positively correlated with the intensity of ethanol consumption.

Alcohol Drinking↗

[Perspectives of therapy of Alzheimer's disease].

Alzheimer's disease is the most common cause of memory disruption in elderly people. The main pathogenic factor of the disease is beta-amyloid protein, which may cause toxic damage of neurones. Other suggested pathogenic factors include an inflammatory process around the senile plaques, apoptosis and necrotic death of neurones, and, in consequence, changes in functioning of neurotransmitter systems. In this article the authors present the main directions in pharmacotherapy of Alzheimer's disease: causal therapy, which prevents the neurodegenerative changes and slows down the pathogenetic process, and symptomatic therapy. The aim of symptomatic therapy is to reduce memory disruption and psychiatric symptoms associated with the disease. Positive influence on cognitive processes is exerted by cholinergic drugs, e.g. the actually used inhibitors of acetylcholinesterase (rivastigmine, donepezil), the nootropic agents (piracetam, nefiracetam) and extracts of Gingko biloba. For treatment of the disease accompanying psychiatric symptoms (anxiety, depression, hallucinations, sleepness) the drugs with minimal influence on cognitive processes are recommended. Attempts at causal therapy are focussed on searching for the substances that can prevent the formation and toxicity of beta-amyloid (droloksifen, estrogens, agonists of muscarinic receptors M1), the cytotoxic influence of excitatory aminoacids (memantine, lamotrigine), calcium (nimodipine) and free radicals (selegiline, alpha-tocoferol), and the development of inflammatory process (non-steroidal antiinflammatory drugs). The new target of research is correction of deficits of nerve growth factor and neurotransmitters by intracerebral implantation of modified fibroblasts. Another way is prevention of the formation of amyloid plaques using appropriate antisense oligonucleotides.

Alzheimer Disease↗

An opioid receptor antagonist, naltrexone, does not alter taste and smell responses in humans.

Several studies have shown that an opioid receptor antagonist, naltrexone, decreases palatable food consumption. Naltrexone has also been reported to reduce ethanol intake in alcohol-preferring rodents and human alcoholics. The aim of the present study was to assess the effects of naltrexone on taste and smell responses in healthy male volunteers. Naltrexone did not alter intensity and pleasantness of sucrose, quinine, citric acid, sodium chloride, and ethanol taste. Similarly, ratings of olfactory stimuli (orange extract and ethanol) and Coca-Cola flavor were not influenced by the opioid antagonist. Our findings may indicate that: (i) naltrexone exerts marginal, if any, effects on gustatory and olfactory responses in humans; (ii) the drug does not alter orosensory responses to ethanol.

Adult↗

Neonatal treatment with 5,7-dihydroxytryptamine induces decrease in alcohol drinking in adult animals.

It has long been suggested that serotonin (5-HT) neurotransmitter system activity is associated with ethanol (ETOH) intake and dependence. The authors studied the effects of neonatal 5,7-dihydroxytryptamine (5,7-DHT) lesions on voluntary alcohol drinking in adult Wistar rats. At 3 days after birth animals were pretreated with desipramine (DMI) and then given a bilateral injection of 5,7-DHT into lateral ventricles. Afterwards, the rats were kept under standard laboratory conditions until at least 2 months of age following which they were tested. 5,7-DHT induced a marked and permanent decrease in brain 5-HT content, measured in the prefrontal cortex, hippocampus and striatum, but did not modify noradrenaline content in these structures. Lesioned animals, both males and females displayed lower preference for ETOH than sham-lesioned animals. Total fluid intake was significantly higher in 5,7-DHT-lesioned than sham-lesioned rats. A significant decrease in body weight was observed in 5,7-DHT-treated rats. This effect was not caused by a significant change in food intake. Both groups showed high preference for a 0.1% saccharin. In conclusion, the present results demonstrated that neonatal treatment with 5,7-DHT evoked long-lasting neurochemical changes and reduction of ETOH intake in adult rats. Neonatally 5,7-DHT-treated rats may be considered as a suitable model in further research on the relationship between the function of central 5-HT system and alcohol intake and dependence.

5,7-Dihydroxytryptamine↗

Accumbens GABA-ergic innervation contributes to the stressor-induced locomotor depression in rats.

The effect of intra-accumbens injections of drugs changing the function of GABA-A and GABA-B receptor systems on stressor-induced motor depression, was studied in rats. Local injections of picrotoxin and baclofen, but not of midazolam and muscimol, attenuated the inhibitory effect of inescapable footshock on locomotor activity in the open field test, examined 24 h after a single exposure of rats to the stressful event. The results obtained with picrotoxin may be related to the general disinhibitory properties of the convulsant on brain neuronal activity, in a period of time important for consolidation of central processes evoked by inescapable shock. The lack of effects of muscimol and midazolam, further underlines the minor and/or indirect role of accumbens GABA-A receptor-related innervation in the neural processes generated by stressful event. On the other hand, the results obtained with baclofen confirm the reports indicating an inverse relationship between the number of GABA-B receptors in the frontal cortex and the development of helpless behavior in rats. It is also noteworthy that most antidepressant drugs which have been shown to prevent or reverse behavioral deficits after inescapable shock, upregulate GABA-B receptors in the frontal cortex. Hence, it appears that GABA-B receptor-related systems within the nucleus accumbens, may contribute to the footshock-induced behavioral depression, including locomotor inhibition. The reduction of stress effect by baclofen does not seem to reflect changes in fear and anxiety, since the drug was given after the stress session, and the anxiolytic midazolam appeared to be ineffective in this test.

Animals↗

[Sigma receptors: the key to therapeutic action or the side-effects of neuroleptics?].

The authors discuss psychotropic effects of phencyclidine (PCP) in the context of neurochemical mechanisms of schizophrenia. They concentrate on sigma receptors and PCP receptors and tie their activity with the dopaminergic system. The authors describe neuroleptic effects on sigma receptors and the therapeutic consequences. They include that the question whether the interaction of neuroleptics with sigma receptors results in therapeutic effects or rather in undesirable symptoms will decide about the future direction of treatment of schizophrenia.

Antipsychotic Agents↗

Effects of drugs influencing serotonergic mechanisms on behaviour of insects.

The present paper deals with effects of some drugs affecting brain serotonergic mechanism on behaviour in cockroach (Periplaneta americana) and immature form (larvae) of ant lion (Myrmeleon formicarius). The effects of para-chlorophenylalanine, LSD-25 and 5-HTP on simple learning mechanisms in cockroach and on behaviour of ant lion (building the funnel-shape traps) were studied. Both p-chlorophenylalanine and LSD-25 facilitated behaviour of insects whilst 5-HTP delayed responses. Our experiments indicate that serotonin may play an inhibitory role upon behavioural processes in some invertebrates.

5-Hydroxytryptophan↗

The role of accumbens serotonin in stress-induced locomotor suppression in rats.

The effect of post-footshock injections of serotonergic agonists into the nucleus accumbens on formation of the open field deficit, has been studied in rats. It was found that the deficient open field behavior, examined 24 h after learned helplessness training, was not modified by local injection of serotonin, buspirone, ipsapirone and ICS 205 930, as well as by peripherally administered citalopram. It is concluded that accumbens serotonin system does not seem to contribute to the balance in the activity of local dopaminergic and GABAergic neurotransmitter mechanisms, previously shown to mediate some behavioral effects of stressors.

Animals↗

Brain serotonin and epileptic seizures in mice: a pharmacological and biochemical study.

5-Hydroxytryptophan (5-HTP) reduced the intensity of both audiogenic and pentylenetrazol seizures. p-Chlorophenylalanine reduced audiogenic seizure (AGS) susceptibility but failed to change the pentylenetetrazol seizure (PTS). Drugs blocking brain serotonin (5-HT) receptors suppressed AGS but caused no clear effects upon PTS. Pentylenetetraziol-induced shock increased brain 5-hydroxyindoleacetic acid (5hiaa) concentrations and decreased 5-HT levels. Single audiogenic shock decreased the acumulation of 5-HT and 5-HIAA in the brains of mice pretreated with 5-HTP. On the other hand PTS increased the accumulation of 5-HT and 5-HIAA in the brains of mice pretreated with 5-HTP. It is suggested that AGS decrease brain 5-HT turnover whilst PTS cause an opposite effect.

5-Hydroxytryptophan↗

Factors which might modify analgesic effect of morphine in differentially housed rats.

The analgesic effect of morphine was studied by tail compression method in grouped and chronically isolated Wistar male rats developing muricide behavior showed increased pain threshold whilst indifferent (non-killer) showed reduced responses to the analgesic action of morphine. "Natural" killer (housed in groups) showed, on the other hand, increased sensitivity to morphine. The role of factors such as isolation period, behavioral pattern and contact with the victim was discussed.

Aggression↗