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Publications (3)17.18 Total impact

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    ABSTRACT: Androgens are involved in regulation of behaviour through intracellular mechanisms owing to their receptors. Involvement of intercellular messengers such as brain norepinephrine and adrenergic receptors (ARs) is seemed to be necessary to realise hormone-dependent behavioural effects. Castration of adult male rats, which decreases copulatory activity in the animals, was accompanied by a significant increase in 3H-clonidine (alpha2-AR agonist) binding site density in the frontal cortex. The levels of mRNA for the alpha2A-ARs (measured by RT-PCR) were increased in the brainstem of castrated males in parallel to the changes in cortical ARs densities. Testosterone treatment, that activates copulatory behaviour in castrates, down regulated alpha2A-AR mRNA levels in the brainstem and 3H-clonidine binding sites densities in the cortex, where terminals of the brain stem neurones are situated. Unlike in the brainstem, castration caused a decrease in alpha2A-AR mRNA in the cortex and testosterone up-regulated this mRNA in the cortical region. The data suggested that down-regulation of alpha2-ARs densities in the cortex that is induced by testosterone can be preferentially related to alpha2-ARs subpopulation which is expressed by the brainstem neurones and imported into the cortex by axons of these neurones.
    Psychoneuroendocrinology 08/2002; 27(5):585-92. · 5.14 Impact Factor
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    ABSTRACT: Antisense strategy was used to investigate the role of alpha2A-adrenoceptor (alpha2A-AR) subtype in anxiety-related behavior. A 18-mer phosphorothioate oligodeoxynucleotide (AS-ODN) complementary to the alpha2A-AR mRNA was administered to the adult male rats for 3 days (1 nmol/5 microl/day) into the region of locus coeruleus (LC). Control groups received infusions of either oligodeoxynucleotide of a random sequence (RS-ODN) or saline. Treatment with AS-ODN significantly reduced the levels of alpha2A-AR mRNA in the brain stem. At the same time, AS-ODN treatment caused only a small reduction in [(3)H]clonidine binding (by 26-32%) in the brain stem which was not significant. Compared to both RS-ODN and saline controls, treatment with AS-ODN significantly increased the percentage of open arm entries in the elevated plus-maze while the total number of arm entries was unaltered. Also, AS-ODN treatment elevated basal levels of plasma corticosterone by 217% and 96% compared to both RS-ODN and saline controls. These changes in the hormone concentrations were at a level of marginal significance (p<0.1 versus random group). Taken together, the data indicate that administration of AS-ODN against alpha2A-ARs in the LC significantly reduced expression of alpha2A-AR mRNA in brain stem, moderately increased plasma corticosterone and had anxiolytic-like effect in the elevated plus-maze.
    Psychoneuroendocrinology 07/2002; 27(5):593-601. · 5.14 Impact Factor
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    ABSTRACT: Clinical and experimental findings have implicated brain alpha2-adrenoceptors in the regulation of many physiological functions, including sexual activity and stress-related behavior. However, which subtypes of the three alpha2-adrenoceptors that have now been cloned (alpha2A, alpha2B, and alpha2C) are involved in these controls have yet to be established. Here, we investigated the contribution of alpha2A-adrenoceptors of the locus ceruleus, the principal source of brain noradrenaline, to exploratory and sexual behaviors. Using administration of antisense oligodeoxynucleotide to inhibit the receptor expression, we found that reductions in brainstem alpha2A-adrenoceptor mRNA levels and alpha2-adrenoceptor densities induced by antisense treatment were not accompanied by any changes in the major characteristics of male sexual activity, such as mount latencies and numbers of mounts. However, in sexual behavior tests, antisense-treated male rats had decreased numbers of rearings and thus have higher percentages of behaviors positively correlated with sexual activity. Besides, antisense-treated animals had decreased anxiety in plus-maze tests. The data demonstrate that inhibition of alpha2A-adrenoceptor expression in the region of the locus ceruleus has an anxiolytic-like effect and facilitates male's attention to female in sexual behavior test.
    Journal of Neuroscience 02/2001; 21(2):726-31. · 6.91 Impact Factor