Suppression of enriched environment-induced neurogenesis in a rodent model of neuropathic pain.
Exposure to an enriched environment (EE) enhances neurogenesis and regulates emotionality. Previous reports have revealed that the rate of neurogenesis can be influenced by various environmental, endocrine, and pharmacologic stimuli. Chronic pain is a debilitating disease state characterized by complex alterations in both peripheral and central nociceptive pathways. In the present study, we evaluated the effect of chronic pain on environmental enrichment-induced hippocampal neurogenesis. Nerve-ligated mice were housed either in a standard environment or in the EE for 4 weeks. EE increased the immunoreactivity for doublecortin (DCX), a marker for immature neuron-positive cells, in the dentate gyrus (DG). Furthermore, the number of NeuroD (a neurogenic basic helix-loop-helix factor)-positive cells, in the DG was clearly increased by EE. Under these conditions, chronic pain suppressed enriched environment-mediated induction of both DCX- and NeuroD-labeled cells. These results suggest that chronic pain has stress-like damaging modulatory effects on hippocampal neurogenesis.
Department of Anesthesiology, University of Toyama, Faculty of Medicine, 2630 Sugitani, Toyama, Toyama 930-0194, Japan.
Mioko
M
Terada
Naoko
N
Kuzumaki
Nana
N
Hareyama
Satoshi
S
Imai
Keiich
K
Niikura
Michiko
M
Narita
Mitsuaki
M
Yamazaki
Tsutomu
T
Suzuki
Minoru
M
Narita
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism; D001522:Behavior, Animal; D002452:Cell Count / Q000379:methods; D049109:Cell Proliferation; D004195:Disease Models, Animal; D000089622:Doublecortin Domain Proteins; D000089662:Doublecortin Protein; D004777:Environment; D006624:Hippocampus / Q000473:pathology / Q000503:physiopathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000502:physiology*; D009479:Neuropeptides / Q000378:metabolism; D010147:Pain Measurement / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D012585:Sciatica / Q000473:pathology* / Q000628:therapy*; D013997:Time Factors
D051792:Basic Helix-Loop-Helix Proteins; D000089622:Doublecortin Domain Proteins; D000089662:Doublecortin Protein; D008869:Microtubule-Associated Proteins; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; C000714847:Dcx protein, mouse; C093564:Neurogenic differentiation factor 1