Spatial memory formation differentially affects c-Fos expression in retrosplenial areas during place avoidance training in rats.
The retrosplenial cortex is involved in spatial memory function, but the contribution of its individual areas is not well known. To elucidate the involvement of retrosplenial cortical areas 29c and 30 in spatial memory, we analyzed the expression of c-Fos in these areas in the experimental group of rats that were trained in a spatial place avoidance task, i.e. to avoid shocks presented in an unmarked sector of a stable arena under light conditions. Control rats were trained in the same context as the experimental rats either without (Control-noUS) or with shocks (Control-US) that were delivered in a random, noncontingent manner for three days. On the first day of place avoidance learning, the experimental group exhibited c-Fos induction in area 29c, similar to both control groups. In area 30, similarly high levels of c-Fos expression were observed in the experimental and Control-US groups. On the third day of training, when the experimental group efficiently avoided c-Fos expression in areas 29c and 30 was lower compared with the first day of training. In area 29c c-Fos level was also lower in the experimental than in comparison to the Control-US group. In area 30, c-Fos expression in the experimental group was lower than in both control groups. In conclusion, areas 29c and 30 appear to be activated during spatial memory acquisition on the first day of training, whereas area 30 seems suppressed during long-term memory functioning on the third day of training when rats effectively avoid.
Laboratory of Molecular and Systemic Neuromorphology, Department of Neurophysiology of Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland. m.malinowska@nencki.gov.pl.
Monika
M
Malinowska
Laboratory of Fungal Glycobiology, Institute of Biochemistry and Biophysics of Polish Academy of Sciences, Warsaw, Poland.
Monika
M
Niewiadomska
Laboratory of Neuropsychology, Department of Neurophysiology of Nencki Institute of Experimental Biology of Polish Academy of Sciences, Warsaw, Poland.
Malgorzata
M
Wesierska
D000704:Analysis of Variance; D000818:Animals; D001362:Avoidance Learning / Q000502:physiology*; D002540:Cerebral Cortex / Q000378:metabolism*; D003214:Conditioning, Classical; D005215:Fasting; D008297:Male; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D051381:Rats; D020318:Rats, Long-Evans; D065852:Spatial Memory / Q000502:physiology*; D013997:Time Factors
D016760:Proto-Oncogene Proteins c-fos