Temporal aspects of spatial task performance during intermittent hypoxia in the rat: evidence for neurogenesis.
Intermittent hypoxia (IH) during sleep, such as occurs in obstructive sleep apnea, leads to degenerative changes in the hippocampus, and is associated with spatial learning deficits in the adult rat. We report that in Sprague-Dawley rats the initial IH-induced impairments in spatial learning are followed by a partial functional recovery over time, despite continuing IH exposure. These functional changes coincide with initial decreases in basal neurogenesis as shown by the number of positively colabelled cells for BrdU and neurofilament in the dentate gyrus of the hippocampus, and are followed by increased expression of neuronal progenitors and mature neurons (nestin and BrdU-neurofilament positively labelled cells, respectively). In contrast, no changes occurred during the course of IH exposures in the expression of the synaptic proteins synaptophysin, SNAP25, and drebrin. Collectively, these findings indicate that the occurrence of IH during the lights on period results in a biphasic pattern of neurogenesis in the hippocampus of adult rats, and may account for the observed partial recovery of spatial function.
Gozal
David
D
Department of Pediatrics, Kosair Children's Hospital Research Institute, University of Louisville School of Medicine, 570 South Preston St., Louisville, KY 40202 USA. david.gozal@louisville.edu
Row
Barry W
BW
Gozal
Evelyne
E
Kheirandish
Leila
L
Neville
Jennifer J
JJ
Brittian
Kenneth R
KR
Sachleben
Leroy R
LR
Guo
Shang Z
SZ
D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D001973:Bromodeoxyuridine / Q000378:metabolism; D003463:Cues; D004924:Escape Reaction; D006624:Hippocampus / Q000378:metabolism / Q000473:pathology*; D000860:Hypoxia / Q000503:physiopathology*; D007150:Immunohistochemistry; D008297:Male; D018782:Maze Learning; D009474:Neurons / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time; D020127:Recovery of Function; D013037:Spatial Behavior / Q000502:physiology*; D013997:Time Factors
D001973:Bromodeoxyuridine; D010100:Oxygen