Contributor:

Czajkowski, Rafał (1976- ) : Supervisor

Publisher:

Instytut Biologii Doświadczalnej im. Marcelego Nenckiego PAN

Place of publishing:

Warszawa

Description:

131 pages : illustrations ; 30 cm ; Bibliography ; Summary in English

Degree name:

PhD in Biological Sciences

Degree discipline :

Biological Sciences

Degree grantor:

Nencki Institute of Experimental Biology PAS ; degree obtained: 2026

Type of object:

Thesis

Abstract:

Retrosplenial cortex (RSC) is an important hub connecting sensory areas with brain structures engaged in spatial memory and navigation. Numerous studies confirm its involvement in processing of visual stimuli. One of the leading hypotheses postulates that RSC plays a crucial role in the ability to shift perspective during exploration of the environment. This work investigates the mechanisms of mouse navigation in an automated T-maze in a paradigm where flexible adaptation to environmental changes is required. The chosen experimental design allowed us to conduct two separate studies. In the first one, mice underwent training leading up to a strategy shift from egocentric alternation to external visual cue-based. In the second one, animals well adapted to the allocentric spatial strategy based on cues with different degrees of complexity were tested in conditions of only partial access to the cues available during the training period. Using two-photon in vivo microscopy we have shown that the differences in the cell turnover (retention and recruitment) during behavioral training is strongly dependent on the time interval between sessions. This makes it difficult to elucidate the underlying mechanisms of processing the presented cues. We show that cells that are active in more than one test session display different patterns of change in fluorescence when comparing sessions with the same cue type versus two distinct ones. This effect is only partially affected by the order of cue presentation, but the two factors cannot be separated without introducing an extended protocol. We used whole-brain c-Fos protein distribution analysis as a tool to verify whether the cues we used are processed in a conceptually distinct way. After exposing two experimental groups to different cue types we were not able to prove the existence of an effect on a global level. We investigated a possible link between c-Fos+ cell density and two behavioral variables. We have found a negative correlation between training duration and the activation of brain structures involved in object recognition, notably the perirhinal cortex (PRC). In the landmark-cue condition PRC exhibited an increased level of c-Fos+ in comparison with the context-cue condition. In summary, the conducted research points to the existence of distinct cellular subpopulations in the RSC, which are differentially engaged during various stages of memory maturation. However, the employed imaging techniques did not allow for separation of the neural activity related specifically to navigation from other processes occurring in parallel within the RSC. In addition, we observed a trend connecting differences in scene perception to the rate of acquisition of a new spatial strategy.

Detailed Resource Type:

PhD Dissertations

Resource Identifier:

oai:rcin.org.pl:248033

Source:

IBD PAN, call no. 20887

Language:

pol

Language of abstract:

eng

Rights:

Rights Reserved - Free Access

Terms of use:

Copyright-protected material. May be used within the limits of statutory user freedoms

Copyright holder:

Publication made available with the written permission of the author

Digitizing institution:

Nencki Institute of Experimental Biology of the Polish Academy of Sciences

Original in:

Library of the Nencki Institute of Experimental Biology PAS

Access:

Open