Alteration of cingulate long-term plasticity and behavioral sensitization to inflammation by environmental enrichment.
Exposure to an enriched environment (EE) has been shown to induce cortical plasticity. Considerable amount of research is focused on the effects of EE in the hippocampus; however, effects of EE on other brain regions and the mechanisms involved are not well known. To investigate this, we induced cortical plasticity by placing mice in an EE for one month and measured the effects of EE in the anterior cingulate cortex (ACC). Here, we show that EE enhanced the expression of the plasticity gene, egr-1, in the ACC of EE animals accompanied by enhanced cingulate long-term potentiation (LTP) and decreased cingulate long-term depression (LTD). The increased NMDA receptor NR2B/NR2A subunits current ratio is associated with the plasticity seen in the ACC while total protein levels remain unchanged. Furthermore, behavioral experiments show that these mice exposed to EE demonstrate enhanced responses to acute and long-term inflammation. Our findings suggest that exposure to EE alters physiological properties within the ACC which results in enhanced responses to inflammation.
Shum
Fanny W F
FW
Department of Physiology, Faculty of Medicine, University of Toronto, University of Toronto Centre for the Study of Pain, 1 King's College Circle, University of Toronto, Toronto, Canada.
Wu
Long-Jun
LJ
Zhao
Ming-Gao
MG
Toyoda
Hiroki
H
Xu
Hui
H
Ren
Ming
M
Pinaud
Raphael
R
Ko
Shanelle W
SW
Lee
Yong-Seok
YS
Kaang
Bong-Kiun
BK
Zhuo
Min
M
D000818:Animals; D001522:Behavior, Animal; D051766:Early Growth Response Protein 1 / Q000378:metabolism; D004777:Environment; D019706:Excitatory Postsynaptic Potentials; D005557:Formaldehyde / Q000008:administration & dosage; D018698:Glutamic Acid / Q000378:metabolism; D006179:Gyrus Cinguli / Q000378:metabolism / Q000503:physiopathology*; D006614:Hindlimb; D066298:In Vitro Techniques; D007249:Inflammation / Q000139:chemically induced / Q000503:physiopathology* / Q000523:psychology*; D007279:Injections, Subcutaneous; D017774:Long-Term Potentiation; D036881:Long-Term Synaptic Depression; D051379:Mice; D008810:Mice, Inbred C57BL; D009473:Neuronal Plasticity; D010146:Pain / Q000523:psychology; D017729:Presynaptic Terminals / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D012449:Safety; D009435:Synaptic Transmission; D013997:Time Factors
D051766:Early Growth Response Protein 1; C486109:Egr1 protein, mouse; C120997:NR2A NMDA receptor; C121001:NR2B NMDA receptor; D016194:Receptors, N-Methyl-D-Aspartate; D005557:Formaldehyde; D018698:Glutamic Acid