title: Diurnal effects of enriched environment on immediate early gene expression in the rat brain.
abstract: Rodents housed in an enriched environment (EE) show increased neuronal plasticity with enhanced long-term potentiation and memory performance. We report an EE-induced increase in NGFI-A and Krox-20 mRNA expression exclusively during the dark period of the day. In addition, EE-housed rats showed considerable diurnal variation in NGFI-A, Krox-20, and NGFI-B mRNA expression which was absent in single-housed rats. Thus, EE-induced molecular changes are more evident during the dark phase when the rats have higher motor and exploratory activity. This is important to take into account in future studies of molecular mediators of experience-dependent neuronal plasticity.
authors.affiliation: Department of Public Health and Clinical Medicine, Medicine, Umeå University Hospital, Sweden.
authors.forename: Annica
authors.initials: A
authors.lastname: Rönnbäck
authors.forename: Per
authors.initials: P
authors.lastname: Dahlqvist
authors.forename: Sven-Anders
authors.initials: SA
authors.lastname: Bergström
authors.forename: Tommy
authors.initials: T
authors.lastname: Olsson
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001921:Brain / Q000378:metabolism; D002940:Circadian Rhythm / Q000235:genetics / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D003624:Darkness; D051766:Early Growth Response Protein 1; D051767:Early Growth Response Protein 2; D004777:Environment; D015870:Gene Expression / Q000502:physiology; D017874:Immediate-Early Proteins / Q000235:genetics / Q000378:metabolism*; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism; D011987:Receptors, Steroid / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; D051766:Early Growth Response Protein 1; D051767:Early Growth Response Protein 2; C497328:Egr2 protein, rat; D017874:Immediate-Early Proteins; C539820:Nr4a1 protein, rat; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D011987:Receptors, Steroid; D014157:Transcription Factors