University of California, Los Angeles

While Einstein revealed the nature of physical space, the nature of mental representation of space is not well understood. The UCLA team lead by Mayank Mehta will address this question at the interface of physics and neurobiology using novel experimental tools and mathematical theories. They hypothesize that mental space is defined by a sequence of neuronal events, or neural ensemble activity patterns. To test this hypothesis, they will focus on a brain region called the hippocampus which is known to be involved in spatial perception and shows spatially selective activity. The team will measure the influence of behavior on hippocampal ensemble activity, including its rhythmicity and the precise spike timing of neurons using whole cell patch clamp, multi-electrode devices and two-photon microscopy. The sequence of neural events measured during natural navigation will be manipulated by a virtual reality system. The emergence of long-term spatial memories will be investigated by determining the influence of calcium influx on hippocampal synaptic plasticity that could permanently encode the sequence of events using distinct neural activity patterns and oscillations. The results could provide a new theory of how a mental representation of space is generated from environmental stimuli, behavior and brain’s internal dynamics.