Brain oscillations and temporal structure of spatial memory pattern retrieval

The hippocampus is a brain structure essentially involved in episodic memory, spatial navigation and other complex cognitive functions. The distinct network architecture of hippocampal CA3 allows to combine converging sensory inputs in creation of complex neural representations. The hippocampus further interacts with the entorhinal cortex to organize knowledge into relational representations, also known as 'cognitive maps'. In rodents, the hippocampal pyramidal neurons behave as place cells, where a neuron is active whenever the subject occupies specific location in the environment. The collective activity of the place cells represents a neural map that is reinstated during repeated exploration of the same space. The place cell maps are thus recognized as neural substrate of spatial memory. In this work, we aimed at better understanding of hippocampal CA3 network dynamics during period of reinstatement of the appropriate place cell representation. We thus analysed CA3 place cell activity recorded during 'teleportation' experiment, where the rats are exposed to abrupt changes in spatial context identity. As shown previously, the network state transitions involve short competitive period, where network state quickly switches between the representations of the previous and the present environment. We..