Spatial- and locomotion-related neural representation in rat hippocampus following long-term survival from ischemia.
Spatial and locomotion-related behavioral correlates of hippocampal cell discharge were compared between ischemic and sham-control rats performing a spatial maze. Ischemic rats showed impaired choice accuracy during maze acquisition, but not during asymptote performance. Single-unit correlates during asymptote performance revealed enhanced spatial selectivity of CA2/3 complex-spike cells coincident with attenuated place-specific firing by hilar complex-spike or subicular cells. Responsivity to locomotion state by stratum granulosum interneurons was exaggerated, and locomotion-induced changes in firing of hilar and subicular interneurons was reduced. Ischemic rats showed recovered spatial learning abilities as evidenced by the fact that acquisition of the spatial task in a second environment was not impaired. Because representational reorganization was also observed in ischemic, maze-naive rats, brain injury per se appears to change information coding schemes.
Mizumori
S J
SJ
Department of Psychology, University of Utah, Salt Lake City 84112, USA. mizumori@behsci.utah.edu
Garcia
P A
PA
Raja
M A
MA
Volpe
B T
BT
D000818:Animals; D001925:Brain Damage, Chronic / Q000503:physiopathology*; D002545:Brain Ischemia / Q000503:physiopathology*; D001931:Brain Mapping; D005071:Evoked Potentials / Q000502:physiology; D006624:Hippocampus / Q000503:physiopathology*; D007395:Interneurons / Q000502:physiology; D008124:Locomotion / Q000502:physiology*; D008297:Male; D018782:Maze Learning / Q000502:physiology*; D011939:Mental Recall / Q000502:physiology*; D009416:Nerve Regeneration / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology; D009949:Orientation / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D009435:Synaptic Transmission / Q000502:physiology*