Finite scale of spatial representation in the hippocampus.

David P Wolfer

David P Wolfer

David P Wolfer

+ -1 Evaluators

Using an exceptionally large arena of 18 m length, this study demonstrates that place cells exist along the entire longitudinal axis of the rat hippocampus, with a topographically graded scale of representation. The size of place fields decreases approximately linearly from about 10 m near the ventral to less than 1 m near the dorsal pole of the hippocampus.

Neil Burgess

Neil Burgess

Neil Burgess

+ -1 Evaluators

The finding in this paper of hippocampal place fields of increasing size throughout the dorso-ventral extent of the rat hippocampus has important implications. Previous findings indicated that spatial processing preferentially involves the dorsal hippocampus {1}, while the ventral hippocampus is more involved in provision of the context of affective or episodic experience. These findings indicate a simpler organizational principal of more detailed spatial representations supporting accurate navigation dorsally and larger-scale representations conveying 'context' ventrally. The finding of place fields up to 10m in length also implies that place cell firing may provide a multi-scale representation of relevance to spatial memory over ecologically valid ranges. Reference: {1} Moser et al. Proc Natl Acad Sci USA 1995, 92:9697-9701 [PMID:7568200].

Michael E Hasselmo

Michael E Hasselmo

Michael E Hasselmo

+ -1 Evaluators

This paper provides a dramatic new perspective on the representation of space by hippocampal place cells by showing that the scale of spatial firing fields for ventral hippocampal neurons increases to large firing fields up to 10 meters in length, compared to fields less than 1 meter in dorsal hippocampus. Combined with new data showing similar increases in spatial scale along the dorsal to ventral axis of entorhinal cortex, this exciting work indicates a systematic neuroanatomical representation of the spatial scale of behavioral experience. The finding of large firing fields in ventral hippocampus suggests that the apparent selective role of ventral hippocampus in the context of fear responses may arise from the coding of larger spatial scales in ventral hippocampus. This Recommendation is of an article referenced in an F1000Prime Report also written by Michael E Hasselmo and Mark P Brandon.

James Knierim

James Knierim

James Knierim

+ -1 Evaluators

This study demonstrates convincingly that spatially tuned firing occurs throughout the dorsal-ventral (septotemporal) axis of the rat hippocampus, with small place fields in the dorsal region and large place fields in the ventral region. Previous studies had shown that small place fields existed in the dorsal hippocampus and larger place fields existed in the intermediate hippocampus {1}. This study extends these results to the ventral pole of the hippocampus, which has been suggested to serve different functions than the dorsal pole based on anatomical connections and lesion studies. The results suggest that spatial representations in the hippocampus exist at different resolutions along the dorsal-ventral axis, and that different brain areas communicate with different regions of the hippocampus depending on the spatial scale necessary for the particular computations they perform. {1} Jung et al. J Neurosci 1994, 14:7347-7356 [PMID:7996180].