The fundamental assumption of a functional system for encoding spatial information lies in the stability and preserved integrity of neural representations. In extreme cases, such as psychotic states in schizophrenia, there is a disruption of this stability, often resulting in the fusion of distinct neural representations. In this study, both familiar (F) and novel (N) linear mazes were utilized to assess the quality of neural coding across various time scales in 3-6 months old rats (N = 12). Lower (0.1 mg/kg) and higher doses (0.15 mg/kg) of MK-801 were administered. We observed disrupted spatial information coding (SI) of place-specific neurons in the N maze with lower-dose treatment, while higher doses led to the disruption of SI in both environments. On the population level, increased similarity of the network, as defined by population vector correlation, was observed in representing F and N mazes after higher-dose treatment, indicating an fusion between maps. Both doses showed decreased inter-trial stability. At a very fine time resolution (125 ms), a similar trend was observed for the N maze with lower doses, while administration of higher doses disrupted precision coding for both F and N environments. Consequently, we compared the level of temporal sequential coding on the time scale defined by theta activity. Lower doses disrupted prospective coding of the processing of novel information, whereas higher doses disrupted prospective coding of both environments. During sleep we observed a reduction in memory reactivation. Acknowledgements: GAČR 22-16717S