Spatial memory formation differentially affects c-Fos expression in retrosplenial areas during place avoidance training in rats

Abstract

Authors' contributions: M.M. designed the research; M.M. and M.W. performed the research, analyzed the data and wrote the paper; M.N. performed ~20% of the research.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 group 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.

Effect of combined administration of aripiprazole and fluoxetine on cognitive functions in female rats exposed to ethyl alcohol

“…Fluoxetine (FLU) is an antidepressant being a selective serotonin reuptake inhibitor (SSRI) used to treat major depressive disorders (MDDs) (Holladay et al 1998). Fluoxetine has been shown to have neuroprotective properties and to improve cognitive functions -memory in particular -in both animals (Li et al 2009, Malinowska et al 2016) and humans (Gudayol-Ferré et al 2015) and, thus, may be used to treat memory disorders in alcohol addicts (Szymańska et al 2009). Memory improvement was also observed in animals exposed to ethyl alcohol (Szymańska et al 2009, Ratajczak et al 2015.…”

The retrosplenial cortex and object recency memory in the rat

“…As already noted, the present study did not find activity differences between the deep or superficial retrosplenial layers with respect to performance. Meanwhile, previous immediate‐early gene studies of spatial memory have found retrosplenial changes across days of training (Maviel et al ., ; Malinowska et al ., ), including switches in c‐ fos expression from deep (recent memory) to more superficial (remote memory) layers (Frankland & Bontempi, ). In addition, electrophysiological analyses of retrosplenial cortex during the development of avoidance learning have highlighted lamina activity differences with respect to different stages of learning (Gabriel et al ., , ; Gabriel & Talk, ).…”

Strategy-Specific Patterns of Arc Expression in the Retrosplenial Cortex and Hippocampus during T-Maze Learning in Rats

“…Finally, immediate early gene studies started to reveal the map of learning-induced plasticity within the structures responsible for spatial memory. This third approach currently allows to visualize the progression of the memory formation process [ 12 , 13 , 28 , 29 ] as well as anatomical differences within the structures involved [ 30 , 31 ]. Our study contributes to the existing body of work by correlating the immediate early genes (IEG) activation with behavioral strategy assumed by rats during the execution of a spatial task.…”