Author(s)

Ramiz M. Salimov, Georgy I. Kovalev

Laboratory of Radioisotope Researches, Zakusov Institute of Pharmacology, Russian Academy of Medical Sciences,Moscow, Russia.

Objectives: 1) To reveal, among spontaneously hypertensive rats, subpopulations that diverge in attention to objects enriching an empty cross-maze; 2) To evaluate effect of clinically efficient drug for treatment of attention deficiency atomoxetine on the attention to environmental cues in attentionally-low rats. Method: A novel paradigm that provides measure of attention towards enriching objects independent of general locomotor activity and spatial orientation is employed. The apparatus consists of 4-arm radial maze, two arms of which contain objects (enriched compartments). Animals exploring the objects typically stay longer in enriched parts of maze than in empty arms and have a higher score of enrichment discrimination ratio. Results: Frequency distribution of the enrichment discrimination ratio had clear bimodal shape that differed significantly from normal distribution suggesting the existence of subpopulations of attentionally-low and -high individuals. The attentionally-low phenotype did not show inferiority in spatial orientation as compared with attentionally-high phenotype. The phenotypes did not differ from each other in measures of locomo- tor activity and blood pressure. Atomoxetine (3 mg/kg, orally, once daily for 4 days) enhanced enrichment discrimina- tion in animals of attentionally-low phenotype. Single administration of the drug was ineffective. Conclusion: Popula- tion of spontaneously hypertensive rat includes two phenotypes of attentionally-low and -high individuals. Subchronic atomoxetine ameliorates attention to environmental cues in attentionally-low rats. The enrichment discrimination test could be useful in studies of neurobiology of attention deficit condition and for screening of novel drug candidates.

Attention Deficit; Enrichment Discrimination; Spontaneously Hypertensive Rat; Atomoxetine

R. Salimov and G. Kovalev, "Enrichment Discrimination Behavior in Spontaneously Hypertensive Rats," Journal of Behavioral and Brain Science, Vol. 2 No. 4, 2012, pp. 479-484. doi: 10.4236/jbbs.2012.24056.