Biomedical subjects

Agnieszka Korkosz

Publications and source records attributed to Agnieszka Korkosz.

8 recordsLinked to original sources

PubMed2006

Effects of ethanol on nicotine-induced conditioned place preference in C57BL/6J mice.

It has been shown that small doses of ethanol (<or= 1.0 g/kg) may antagonize the discriminative stimulus properties of nicotine. The aim of the present study was to evaluate whether ethanol could antagonize nicotine's rewarding effects in the conditioned place preference procedure. For comparison, effects of ethanol on nicotine-induced seizures were assessed. Male C57BL/6J mice were used in all experiments. Lower doses of nicotine (0.3 and 0.6 mg/kg, s.c.) induced significant conditioned place preference, while higher doses (0.9 and 1.2 mg/kg) induced neither conditioned place preference nor conditioned place aversion. In the following experiments, ethanol (0.5 or 1.0 g/kg, i.p.) was administered 5 min before 0.3 mg/kg nicotine. Ethanol did not antagonize nicotine-induced conditioned place preference. Contrary to our hypothesis, a non-significant (p = 0.07) enhancement of nicotine-induced place preference conditioning was observed in mice pre-treated with 1.0 g/kg ethanol. Both doses of ethanol (0.5 and 1.0 g/kg) suppressed seizures elicited by a high dose of nicotine (6.0 mg/kg). Ethanol totally eliminated clonic-tonic component of nicotine-induced seizures. Maximal blood ethanol levels after i.p. administration of 0.5 or 1.0 g/kg ethanol exceeded 60 and 115 mg%, respectively. The present results may indicate that the rewarding and seizure-inducing effects of nicotine are differentially modulated by clinically relevant concentrations of ethanol in mice.

Analysis of Variance↗

PubMed2006

Nicotine-induced conditioned taste aversion in the rat: effects of ethanol.

It has been shown that small doses of ethanol antagonise the discriminative stimulus properties of nicotine in the rat. The aim of the present study was to evaluate whether ethanol could antagonise the aversive stimulus effects of nicotine. Wistar rats were trained to associate nicotine injections with a novel tasting fluid (0.1% saccharin) in the conditioned taste aversion procedure. Nicotine (0.3 mg/kg, s.c.) was injected 5 min after the end of a 20-min exposure to the saccharin solution. Ethanol (0.25-0.5 g/kg, i.p.) was administered 5 or 50 min before nicotine. In general, ethanol did not inhibit nicotine-induced conditioned taste aversion. Contrary to the findings in drug discrimination studies, a slight but significant enhancement of nicotine-induced taste aversion conditioning was observed after ethanol pre-treatment. Blood ethanol levels were measured in a separate group of rats. Maximal blood ethanol levels after i.p. administration of 0.25 or 0.5 g/kg ethanol exceeded 20 and 80 mg%, respectively. Concluding, the present results may indicate that ethanol does not attenuate nicotine-induced conditioned taste aversion in the rat.

Animals↗

PubMed2005

Extended blockade of the discriminative stimulus effects of nicotine with low doses of ethanol.

The aim of the present study was to further evaluate effects of ethanol on nicotine discrimination and to correlate these effects with blood ethanol levels. Rats were trained to discriminate 0.3 mg/kg nicotine from its vehicle in the standard two-lever operant procedure. In antagonism tests, small doses of ethanol (0.25-0.5 g/kg) were injected either 5 or 50 min before nicotine. Both doses of ethanol partially antagonized the nicotine cue regardless of the pre-treatment time. Ethanol attenuated also inhibitory effects of nicotine on the rate of responding. Suppression of the cueing effects of nicotine was noted even 60 min after the injection of 0.25 g/kg ethanol, i.e. at the time point when the blood ethanol level was close to zero. Ethanol-induced antagonism of the nicotine cue disappeared when longer time (110 min) was allowed to elapse between the ethanol (0.5 g/kg) and nicotine injection. Concluding, the present results may indicate that the effects of ethanol on nicotine discrimination are not primarily related to blood ethanol levels.

Animals↗

PubMed2004

Taste responses to monosodium glutamate after alcohol exposure.

AIMS: The aim of the present study was to evaluate the effects of acute and chronic exposure to alcohol on taste responses to a prototypic umami substance, monosodium glutamate (MSG). METHODS: The rated intensity and pleasantness of MSG taste (0.03-10.0%) was compared in chronic male alcoholics (n = 35) and control subjects (n = 25). In a separate experiment, the effects of acute exposure of the oral mucosa to ethanol rinse (0.5-4.0%) on MSG taste (0.3-3.0%) were studied in 10 social drinkers. RESULTS: The alcoholic and control group did not differ in terms of the rated intensity and pleasantness of MSG taste. Electrogustometric thresholds were significantly (P < 0.01) higher, i.e. worse, in the alcohol-dependent subjects. The difference remained significant after controlling for between-group differences in cigarette smoking and coffee drinking. Rinsing with ethanol did not alter either intensity or pleasantness of MSG taste in social drinkers. CONCLUSIONS: The present results suggest that: (i) neither acute nor chronic alcohol exposure modifies taste responses to MSG; (ii) alcohol dependence may be associated with deficit in threshold taste reactivity, as assessed by electrogustometry.

Adult↗

PubMed2004

Depressive symptoms and taste reactivity in humans.

Animal studies suggest that induction of depression-like states may alter preference for sweet tastants. A major goal of the present study was to search for correlations between depressive symptoms measured by the Beck Depression Inventory (BDI) and taste responses to sweet and bitter substances. Thirty-three nonclinical volunteers rated intensity and pleasantness of chocolate and vanilla milk as well as of sucrose- and quinine-soaked filter paper disks. Reactivity to citric acid (sour) and sodium chloride (salty) was also tested with the paper disk methodology. Taste detection thresholds were assessed by means of electrogustometry. A weak inverse relationship was found between the BDI scores (range: 3-33) and rated intensity of paper disks soaked in 60% sucrose. No correlations were found between depressive symptoms and intensity, pleasantness or identification of the other samples. Similarly, there was no relationship between the BDI scores and responses to chocolate and vanilla milk. BDI scores were not associated with electrogustometric thresholds. These data suggest that depressive symptoms may not influence taste reactivity in nonclinical population.

Aconitic Acid↗

PubMed2004

Dissociation of ethanol and saccharin preference in fosB knockout mice.

The Fos family of transcription factors may play a key role in various forms of brain plasticity. Among different genes coding Fos proteins is the fosB gene. Protein products of the fosB gene are thought to be critically involved in neural adaptations produced by chronic treatment with drugs of abuse. fosB gene transcription leads to accumulation of full-length FosB as well as its truncated form, deltafosB. Stable isoforms of deltafosB called chronic FRAs accumulate in the brain after chronic administration of various drugs of abuse. The purpose of the present study was to evaluate the role of the fosB gene in two-bottle choice ethanol self-administration. For this aim, ethanol (2-8% v/v) intake and preference was assessed in fosB mutant (n=17) and wild-type (WT) mice (n=16). For comparison, consumption of saccharin (0.05-0.8% w/v) and quinine (15-960 microM) solutions was assessed in the same animals. Ethanol preference in both groups varied from around 50% for the lowest to 20% for the highest ethanol concentration. Neither ethanol intake (g/kg) nor preference differed between the two genotypes. In contrast, saccharin preference, but not intake, was higher in the fosB mutants. Only slight and inconsistent between-group differences were observed in terms of quinine preference. The present results suggest that permanent elimination of fosB gene products does not alter ethanol intake but may enhance preference for sweet solutions in mice.

Alcohol Drinking↗

PubMed2004

Time-dependent changes in alcohol-seeking behaviour during abstinence.

Exposure of alcohol addicts to alcohol-related environmental cues may elicit alcohol-seeking behaviour even after protracted abstinence. The purpose of the present study was to assess time-dependent changes in alcohol-seeking behaviour in rats trained to respond for alcohol. The rats were re-exposed to alcohol-associated stimuli after 1, 28 or 56 days of withdrawal. During the re-exposure session, the rats were first allowed to respond in extinction. Then, reinstatement of alcohol-seeking behaviour was evoked by a complex of discrete alcohol-associated cues (auditory and light cues combined with taste and smell of alcohol). Extinction behaviour depended on abstinence duration with maximal responding after 28-day abstinence. Reinstatement of alcohol-seeking behaviour evoked by the discrete cues was highest after 56-day abstinence. No correlations were found between individual alcohol intakes, extinction behaviour and cue-induced reinstatement. These results suggest that: (i) alcohol-seeking behaviour may become more intense after long-term imposed abstinence; (ii) alcohol self-administration, extinction behaviour, and reinstatement of alcohol-seeking behaviour may be regulated by separate neural mechanisms.

Alcoholism↗

PubMed2003

Chorda tympani nerve transection does not alter operant oral self-administration of ethanol in the rat.

In experimental conditions, it has been suggested that taste factors may contribute to ethanol preference in rodents. The aim of the current study was to assess the effects of transection of a gustatory branch of the seventh cranial nerve, the chorda tympani (CT), on operant self-administration of ethanol in rats. Male Wistar rats were trained to lever press for 8% [volume/volume (vol./vol.)] ethanol solution. When 8% ethanol intake stabilized, the CT nerve was transected bilaterally in six subjects. Another group received sham operations. There were no between-group differences in terms of self-administration of 8% ethanol, either before or after surgery. In addition, self-administration of 2% and 4% ethanol, measured after surgery, did not differ between the groups. In a control experiment, two-bottle consumption of as well as preference for 0.625% [weight/volume (wt./vol.)] sucrose were significantly decreased in the lesioned subjects. The results may indicate that gustatory input of the CT nerve is not necessary for maintenance of operant oral self-administration of ethanol.

Animals↗