RT Journal Article
SR Electronic
T1 Spatial Information Encoding across Multiple Neocortical Regions Depends on an Intact Hippocampus
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 307
OP 319
DO 10.1523/JNEUROSCI.1788-20.2020
VO 41
IS 2
A1 Ingrid M. Esteves
A1 HaoRan Chang
A1 Adam R. Neumann
A1 JianJun Sun
A1 Majid H. Mohajerani
A1 Bruce L. McNaughton
YR 2021
UL http://www.jneurosci.org/content/41/2/307.abstract
AB There has been considerable research showing populations of neurons encoding for different aspects of space in the brain. Recently, several studies using two-photon calcium imaging and virtual navigation have identified “spatially” modulated neurons in the posterior cortex. We enquire here whether the presence of such spatial representations may be a cortex-wide phenomenon and, if so, whether these representations can be organized in the absence of the hippocampus. To this end, we imaged the dorsal cortex of mice running on a treadmill populated with tactile cues. A high percentage (40–80%) of the detected neurons exhibited sparse, spatially localized activity, with activity fields uniformly localized over the track. The development of this location specificity was impaired by hippocampal damage. Thus, there is a substantial population of neurons distributed widely over the cortex that collectively form a continuous representation of the explored environment, and hippocampal outflow is necessary to organize this phenomenon.SIGNIFICANCE STATEMENT Increasing evidence points to the role of the neocortex in encoding spatial information. Whether this feature is linked to hippocampal functions is largely unknown. Here, we systematically surveyed multiple regions in the dorsal cortex of the same animal for the presence of signals encoding for spatial position. We described populations of cortical neurons expressing sequential patterns of activity localized in space in primary, secondary, and associational areas. Furthermore, we showed that the formation of these spatial representations was impacted by hippocampal lesion. Our results indicate that hippocampal inputs are necessary to maintain a precise cortical representation of space.