title: Do two models of acute and chronic stress stimulation influence the amount of nerve growth factor (NGF) and its receptor TrkA in the hippocampal neurons of middle aged rats?
abstract: Our study aimed to explore the influence of two different stressors: acute (once for 15 min) and chronic (15 min daily for 21 days) exposure to high light open field (HL-OF) or forced swim (FS) on the density of nerve growth factor (NGF) and tyrosine kinase A (TrkA) immunoreactive neurons in the hippocampal CA1 and CA3 pyramidal cell layers and dentate gyrus (DG) granule cell layer in middle aged (360 days old; P360; P, postnatal day) rats. In contrast to non-stressed animals, acute HL-OF stimulation resulted in an increase (p<0.001) in the density of NGF-ir cells in CA1, CA3, DG, whereas chronic HL-OF produced no changes in all hippocampal regions. The rats which underwent acute and chronic FS tests showed no statistically significant differences in the density of NGF-ir containing cells in the CA1, CA3, and DG subfields compared with control rats. Except for DG, where after 21 days of FS the density of TrkA-ir neurons was found to increase (p<0.05) in comparison to unstressed rats, no changes were noted in the density of TrkA-ir in the studied hippocampal structures as a result of acute and chronic HL-OF or FS exposure. These results indicate that acute HL-OF stress stimulation was the only factor inducing changes in the density of NGF-ir containing neurons in the hippocampal CA1, CA3, and DG of middle aged rats. In respect of the density of NGF-ir and TrkA-ir cells in the hippocampal structures, prolonged exposure to HL-OF or FS stressors did not constitute an aggravating factor for rats in the studied ontogenetic period.
authors.affiliation: Department of Anatomy and Neurobiology, Medical University of Gdańsk, Dębinki 1 St., 80–211 Gdańsk, Poland. ewabadowska@gumed.edu.pl
authors.forename: Ewa
authors.initials: E
authors.lastname: Badowska-Szalewska
authors.forename: Edyta
authors.initials: E
authors.lastname: Spodnik
authors.forename: Ilona
authors.initials: I
authors.lastname: Klejbor
authors.forename: Beata
authors.initials: B
authors.lastname: Ludkiewicz
authors.forename: Janusz
authors.initials: J
authors.lastname: Moryś
mesh_terms: D000223:Adaptation, Psychological / Q000502:physiology; D000367:Age Factors; D000704:Analysis of Variance; D000818:Animals; D004195:Disease Models, Animal; D005106:Exploratory Behavior / Q000502:physiology; D006624:Hippocampus / Q000473:pathology*; D008297:Male; D020932:Nerve Growth Factor / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D020917:Receptor, trkA / Q000378:metabolism*; D013315:Stress, Psychological / Q000473:pathology*; D013550:Swimming / Q000523:psychology; D013997:Time Factors
chemical_list: D020932:Nerve Growth Factor; D020917:Receptor, trkA