Effects of early experience on c-fos gene expression in the chick forebrain

• Published in: Brain research Vol. 544; no. 1; p. 101
• Main Authors: Anokhin, K V, Mileusnic, R, Shamakina, I Y, Rose, S P
• Format: Journal Article
• Language: English
• Published: Netherlands 22.03.1991
• Subjects: Animals; Avoidance Learning; Brain - physiology; Chickens; Darkness; Female; Gene Expression; Light; Male; Organ Specificity; Photic Stimulation; Protein-Tyrosine Kinases - genetics; Proto-Oncogene Proteins - genetics; Proto-Oncogene Proteins c-fos; Proto-Oncogenes; RNA, Messenger - genetics; RNA, Messenger - metabolism; Vision, Monocular
• ISSN: 0006-8993
• DOI: 10.1016/0006-8993(91)90890-8

The expression of c-fos mRNA was studied by blot and in situ hybridisation in the forebrains of young chicks subjected to different types of experience-dependent stimulation. Exposure to one hour of activity in a rich visual environment produced a significant increase in forebrain c-fos mRNA in 1-day or 2-day-old chicks; this increase was most marked in cerebellum and medial forebrain--especially intermediate medial hyperstriatum ventrale (IMHV) regions. Levels of c-fos mRNA were not elevated in birds which had been accommodated to the enriched environment for 2 days, suggesting that the novelty of presented stimuli play a critical role in the c-fos induction. Training chicks on a one-trial passive avoidance task was followed by 2- to 2.5-fold increases in c-fos mRNA in both left and right IMHV and lobus parolfactorius (LPO) 30 min after the learning experience. Occlusion of one eye during training resulted in an asymmetrical expression of c-fos in the hemisphere contralateral to the open eye. Therefore c-fos is induced in the chick forebrain during learning and its activation cannot be attributed to 'stress', arousal or intensity of sensory stimulation alone. These observations support the hypothesis that c-fos expression in the brain is related to the acquisition of new experience.