Biomedical subjects

Katarzyna Radwanska

Publications and source records attributed to Katarzyna Radwanska.

4 recordsLinked to original sources

PubMed2006

Cycloheximide impairs acquisition but not extinction of cocaine self-administration.

The aim of the present study was to assess the role of de novo protein synthesis in the acquisition and extinction of cocaine self-administration. In a first experiment, rats were trained to respond for intravenous cocaine infusions (0.3 mg/kg) and a protein synthesis inhibitor, cycloheximide (CHX; 3 mg/kg, s.c.) was injected immediately after each self-administration session. In a second experiment, rats were allowed to acquire cocaine self-administration and CHX was injected immediately after subsequent extinction sessions. CHX impaired the acquisition, but not extinction, of cocaine self-administration. In control experiments, CHX (3 mg/kg) blocked c-Fos protein expression after foot-shock stress and impaired the acquisition of conditioned freezing but did not inhibit spontaneous locomotor activity and sucrose drinking. Our results suggest that: i) the acquisition and extinction of cocaine-reinforced behaviour have a different molecular basis; and ii) only the former process requires de novo protein synthesis.

Animals↗

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

Evaluation of mRNA expression of estrogen receptor beta and its isoforms in human normal and neoplastic endometrium.

Endometrial cancer is well known to be estrogen-dependent. Two estrogen receptor types, ERalpha and ERbeta, are major mediators of a diversity of biologic functions of estrogen and play an important role in estrogen-dependent tissues and cancers. Cloning of ERbeta was followed by the discovery of a variety of its isoforms. Using real-time RT-PCR, the relative expression levels of ERbeta1, ERbeta2 (ERbetacx), ERbeta3, ERbeta4 and ERbeta5 were studied. We observed coexpression of ERbeta isoforms in the endometrium and upregulation of the ERbeta5 transcript in malignant endometrium. We also observed downregulation of ERbeta2Delta5 transcript in neoplastic endometrium, using a semiquantitative method. Our results suggest that analyzing the changes in ERbeta and its isoforms may be important in the diagnosis, prognosis and treatment of endometrial cancer.

Adenocarcinoma↗

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↗