Self-Motion and the Hippocampal Spatial Metric

• DOI: 10.1523/jneurosci.0693-05.2005
• Publication Date: 2005-08-31T19:18:36Z
• Authors: Alejandro Terrazas; Michael Krause; Peter Lipa; Katalin M. Gothard; Carol A. Barnes; Bruce L. McNaughton
• Keywords: Path integration

Self-motion signals are sufficient for animal navigation (“path integration”) and updating hippocampal location-specific firing. The contributions of ambulatory, vestibular, optic self-motion to CA1 unit activity EEG were studied while rats either walked or drove a car between locations on circular track (referred as WALK CAR, respectively) experienced pseudomotion, in which the was stationary environment rotated (WORLD). Fewer pyramidal cells expressed place fields during CAR those that did exhibited substantially larger fields. number theta cycles required traverse field increased, whereas slope phase firing versus position function reduced. presence and/or location not well correlated conditions. These effects even more accentuated WORLD. results explainable by simple “smearing out” but, terms size relative size, comparable with what would be observed if circumference reduced moved around it at correspondingly slower speed. Theta (and its 14–18 Hz harmonic) power dependent velocity, but gain this WORLD, again rat moving slowly. spatial scale over population vector is updated appears derived primarily from velocity signal approximately equal components ambulation, optic-flow signals.