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Dvorakova, T.

Publications and source records attributed to Dvorakova, T..

2 recordsLinked to original sources

Internal representation of future interactions in rats

Animals and humans receive the most critical information from parts of the environment that are immediately inaccessible, possibly only visually explored, and highly dynamic. The brain must effectively process potential interactions between elements in such an environment to make appropriate decisions in critical situations. We trained male Long-Evans rats to discriminate static and dynamic visuospatial stimuli displayed on an inaccessible computer screen. We demonstrated that the rats learned to discriminate dynamic visuospatial stimuli faster, with greater accuracy and shorter reaction time than complementary static stimuli. Furthermore, we provide behavioral evidence indicating that rats internally represent dynamic environments as static maps that capture meaningful future interactions. These observations highlight the ecological importance of dynamic stimuli in the outside world and support previous findings in humans that internal static representations can encapsulate relevant spatiotemporal information of dynamic environments. Such a mechanism would allow animals and humans to process complex time-changing situations neatly.

animal behavior and cognition↗

Is Rapid Eye Movement Sleep a Paradoxical State of Sleep?

Rapid eye movement sleep (REM) is often considered as a homogeneous state of sleep. However, the frequent occurrence of transient events indicates that it may be separated into two distinct, phasic and tonic, substates. During tonic REM, we found local appearances of spindle waves in the barrel cortex concomitant with strong delta power on the local field potential. Subthreshold spindle oscillations in neurons of the ventral posterior medial nucleus further confirmed the thalamic origin of these cortical spindles. Spindle oscillations were suppressed in phasic REM, while thalamus spike firing increased associated with rapid whisker movements of mice and cortical activity transitioned to an activated state. During REM, sensory thalamus and barrel cortex therefore alternate between high (wake-like) and low (non-REM sleep-like) activation states, possibly allowing transient sensory integration windows to emerge throughout this paradoxical sleep stage.

neuroscience↗