There are many active research projects accessing and applying shared ADNI data. Use the search above to find specific research focuses on the active ADNI investigations. This information is requested annually as a requirement for data access.
| Principal Investigator | |
| Principal Investigator's Name: | Manuela Dorado |
| Institution: | University of Washington |
| Department: | Physiology & Biophysics |
| Country: | |
| Proposed Analysis: | OVERVIEW The hippocampus was first shown to encode maps of the physical environment, with place cells that are only active when an animal occupies the cell’s preferred location (1). Other, more recent, electrophysiological studies in rodents and monkeys have demonstrated that space alone is not a sufficient predictor of hippocampal activity. Instead, hippocampal neurons conjunctively code different aspects of behavioral task structures (2–4). The framework of my research plan is concerned with the following hypothesis: by tracking salient aspects of ongoing experiences, the hippocampal navigation system —potentially as a result of evolution— links sequences of events in cohesive episodes. If the episodes are relevant for future behavior, the hippocampus will relay them to cortical structures that will encode them as long-term memories. Specific aims Aim 1: Identify task-related representations in the hippocampal formation during virtual navigation I will record the spiking activity of multiple neurons throughout the hippocampus while monkeys engage in a virtual visuospatial navigation task. I will test the hypothesis that neurons in the hippocampal formation represent salient aspects of the task, with space being one of many encoded dimensions of the ongoing experience. Aim 2: Identify the role of temporally structured population activity during virtual navigation Temporally structured activity at specific time scales is a hallmark of hippocampal circuits. Most prominently, synchronized population activity at about 4 - 10 Hz (theta activity) represents the online state of the hippocampus (5), with eye movements resetting the phase of theta during learning of novel visual information (6). I will test the hypothesis that theta activity coordinates information across the hippocampal circuit, acting like a syntactic clock and sequencing mechanism that, through its phase reset with eye (and potentially hand-joysticks) movements, provides a unifying principle for the computation of ongoing experiences. |
| Additional Investigators |
