 Research FocusThe main goals of my research group are to understand the contribution of the hippocampal formation to memory, and to investigate how the hippocampus and its connections with cortical and subcortical structures allow information to be learned and remembered. We are using an integrated approach to this problem, using multiple single-unit recording from awake, behaving rats, neurochemical lesions, neuropharmacological disruption of synaptic transmission and plasticity processes, and behavioural techniques. The group is currently conducting research focused around three related projects: 1. Exploring the role of the hippocampus in episodic memoryThe hippocampus is required for episodic memory, but the precise role it plays, and the neural mechanisms involved are not completely understood. To elucidate the specific contribution to episodic memory made by the hippocampus, and the role of specific structures within the hippocampus, we are testing the effects of complete and subfield-specific hippocampal lesions in rats on tasks that tax various aspects of event memory. These include recognition memory tasks that require integrated memory for specific events including what happened where and in which context, or what happened where and when. Other tasks, such as the one-trial paired associate task in the event arena (Tse et al, 2007) and the E-maze task (Eacott et al, 2005) involve cued recall of integrated what-where or what-where-which information.
Stimuli used for testing recognition of integrated what, where and which information 2. Hippocampal mechanisms of episodic memory
3. Interactions between head direction cells, grid cells and place cellsWe are interested in understanding the functional relationships between the interconnected set of cortical and sub-cortical structures that have activity related to allocentric space – that is, place cells in hippocampal structures, grid cells in the entorhinal cortex, and head direction cells in a network of structures including the anterior thalamus, postsubiculum and entorhinal cortex. In one set of experiments we are investigating how spatial landmarks control place cells, grid cells, head direction cells, and spatial behaviour? Mammals readily recognise where they are in their environment by learning the spatial relationships between landmarks. This project, conducted in collaboration with Dr Paul Dudchenko (Stirling) combines behaviour and single unit recording to test the hypothesis that the postsubiculum, a critical input structure to the hippocampus, is the site of neuronal plasticity underlying this rapid form of learning. The project involves reversibly blocking plasticity in the postsubiculum of rats as they encode new environments, and assessing how this affects landmark control of hippocampal place cells, entorhinal grid cells, head direction cells and spatial behaviour. In a second set of experiments (also in collaboration with Paul Dudchenko), we are exploring the functional role of head direction cells in spatial navigation based on path integration. Research GroupCurrent members:
Alumni (where are they now?):
Selected Publicationsvan der Meer MAA, Knierim JJ, Yoganarasimha D, Wood ER, van Rossum MCW (2007) Anticipation in the rodent head direction system can be explained by an interaction of head movements and vestibular firing properties. J. Neurophysiology (in press) Ainge JA, Dudchenko PA, Wood ER (2007) Context-dependent firing of hippocampal place cells: does it underlie memory? In Hippocampal place fields: Relevance to learning and memory, S.J. Mizumori (Ed.), Oxford University Press. (in press) Ainge JA, van der Meer MAA, Langston RL, Wood ER (2007) Exploring the role of context-dependent hippocampal activity in spatial alternation behaviour Hippocampus (Published Online: 6 Jun 2007 DOI: 10.1002/hipo.20301) Tse D, Langston RF, Kakeyama M, Bethus I, Spooner PA, Wood ER, Witter MP, Morris RGM (2007) Schemas and memory consolidation. Science 316: 76-82 de Hoz L, Wood ER (2006) Dissociating the past from the present in the activity of place cells. Hippocampus 16(9): 704-715 Ainge JA, Heron-Maxwell C, Theofilas P, Wright P, de Hoz L, Wood V (2006) The role of the hippocampus in object recognition in rats: the influence of task parameters and lesion size. Behavioural Brain Research 167: 183-195 Wood ER, Agster K, Eichenbaum H (2004) One trial odour-reward association: A form of event memory not dependent on hippocampal function. Behavioral Neuroscience 118(3): 526-539 Wood ER, Dudchenko PA, Robitsek RJ, Eichenbaum H (2000) Hippocampal neurons encode information about different types of memory episodes occurring in the same location. Neuron 27: 623-633 Wood ER, Dudchenko PA, Eichenbaum H (1999) The global record of memory in hippocampal neuronal activity. Nature 397: 613-616 Eichenbaum H, Dudchenko PA, Wood ER, Shapiro M, Tanila H (1999) The hippocampus, memory, and place cells: Is it spatial memory or a memory space? Neuron 23: 209-226  |
