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Human Hippocampal Activation during Stance and Locomotion
Author(s) -
Jahn Klaus,
Wagner Judith,
Deutschländer Angela,
Kalla Roger,
Hüfner Katharina,
Stephan Thomas,
Strupp Michael,
Brandt Thomas
Publication year - 2009
Publication title -
annals of the new york academy of sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.712
H-Index - 248
eISSN - 1749-6632
pISSN - 0077-8923
DOI - 10.1111/j.1749-6632.2009.03770.x
Subject(s) - hippocampal formation , neuroscience , parahippocampal gyrus , vestibular system , psychology , entorhinal cortex , fusiform gyrus , lingual gyrus , functional magnetic resonance imaging , temporal lobe , epilepsy
The hippocampal formation, including the parahippocampal gyrus, is known to be involved in different aspects of navigation and spatial orientation. Recently, bilateral parahippocampal activation during mental imagery of walking and running was demonstrated in fMRI. For the current study the question was whether distinct functional regions within the hippocampal formation could be defined from the analysis of brain activity during imagery of stance and locomotion in healthy, blind, and vestibular‐loss subjects. Using the same experimental paradigm in all groups (fMRI during mental imagery of stance and locomotion after training of actual performance, regions of interest [ROI] analysis), activations were found in the hippocampal formation, predominantly on the right side, in all subjects. In healthy subjects, standing was associated with anterior hippocampal activation; during locomotion widespread activity was found in the right parahippocampal gyrus. Compared to healthy controls, blind subjects showed less activity in the right dorsal parahippocampal region, whereas vestibular‐loss subjects had less activity in the anterior hippocampal formation. The findings show that the hippocampal formation in humans processes visual and vestibular signals in different regions. The data support the assumption that the anterior hippocampus and the entorhinal cortex in the parahippocampal region are input areas for vestibular and somatosensory signals. Posterior parahippocampal and fusiform gyri, which are connected to visual cortical areas, are more important for visually guided locomotion and landmark recognition during navigation. The right‐sided dominance reflects the importance of the right hemisphere for spatial orientation.