[Effects of sex factors and hemispheric localization on the involvement of serotonin from the frontal cortex, striatum, and nucleus accumbens into the processing of novel and repeatedly presented information in rats].
The effects of novel or relevant (a single exposure to experimental chamber) and irrelevant (20 exposures to experimental chamber) stimuli on the levels of serotonin (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) in the frontal cortex, striatum, and nucleus accumbens in the left and right hemispheres were studied in male and female rats. It was found that 5-HT and 5-HIAA contents in the frontal cortex changed in response to neither relevant nor irrelevant stimuli. However, there were hemispheric difference in 5-HT and 5-HIAA in the frontal cortex of intact animals. The level of 5-HT in males and the level of 5-HIAA in females were higher in the left frontal cortex. In females, the level of 5-HIAA in the left striatum decreased in response to the novel stimulus. Sex differences in: a) 5-HT metabolism (increase in the level of 5-HIAA in males and increase in 5-HT in females) and b) lateralization (the striatal 5-HT metabolism in males changed bilaterally and only in the left hemisphere in females) were observed in reactions to irrelevant stimuli. Both in male and female rats, serotonin content in the nucleus accumbens changed only in response to the irrelevant stimuli. The 5-HT level increased in the left and right hemispheres independently of sex, but hemispheric difference was revealed only in females, in which the serotonin level was higher in the left nucleus accumbens. It is concluded that serotonergic neurotransmitter mechanisms are involved in hemispheric and sex differences in selective attention.
Institute of Physiology, Russian Academy of Medical Sciences, Siberian Branch, Novosibirsk.
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Molodtsova
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D003342:Corpus Striatum / Q000378:metabolism / Q000502:physiology*; D005260:Female; D005625:Frontal Lobe / Q000378:metabolism / Q000502:physiology*; D007839:Functional Laterality; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D008297:Male; D008606:Mental Processes / Q000502:physiology*; D009714:Nucleus Accumbens / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000378:metabolism / Q000502:physiology*; D012737:Sex Factors
D012701:Serotonin; D006897:Hydroxyindoleacetic Acid