title: The effects of MyD88 deficiency on exploratory activity, anxiety, motor coordination, and spatial learning in C57BL/6 and APPswe/PS1dE9 mice.
abstract: Toll-like receptors (TLRs) are a family of pattern-recognition receptors in innate immunity and provide a first line defense against pathogens and tissue injuries. In addition to important roles in infection, inflammation, and immune diseases, recent studies show that TLR signaling is involved in modulation of learning, memory, mood, and neurogenesis. Because MyD88 is essential for the downstream signaling of all TLRs, except TLR3, we investigated the effects of MyD88 deficiency (MyD88-/-) on behavioral functions in mice. Additionally, we recently demonstrated that a mouse model of Alzheimer's disease (AD) deficient for MyD88 had decreases in Aβ deposits and soluble Aβ in the brain as compared with MyD88 sufficient AD mouse models. Because accumulation of Aβ in the brain is postulated to be a causal event leading to cognitive deficits in AD, we investigated the effects of MyD88 deficiency on behavioral functions in the AD mouse model at 10 months of age. MyD88 deficient mice showed more anxiety in the elevated plus-maze. In the motor coordination tests, MyD88 deficient mice remained on a beam and a bar for a longer time, but with slower initial movement on the bar. In the Morris water maze test, MyD88 deficiency appeared to improve spatial learning irrespective of the transgene. Our findings suggest that the MyD88-dependent pathway contributes to behavioral functions in an AD mouse model and its control group.
authors: Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, P.O. Box 1649, Peoria, IL 61656, USA.
authors: Jeong-Eun
authors: JE
authors: Lim
authors: Min
authors: M
authors: Song
authors: Jingji
authors: J
authors: Jin
authors: Jinghong
authors: J
authors: Kou
authors: Abhinandan
authors: A
authors: Pattanayak
authors: Robert
authors: R
authors: Lalonde
authors: Ken-Ichiro
authors: K
authors: Fukuchi
mesh_terms: D000544:Alzheimer Disease / Q000150:complications* / Q000235:genetics; D016564:Amyloid beta-Protein Precursor / Q000235:genetics; D000818:Animals; D001007:Anxiety / Q000209:etiology*; D004195:Disease Models, Animal; D005106:Exploratory Behavior / Q000502:physiology*; D006801:Humans; D018782:Maze Learning / Q000502:physiology; D008568:Memory / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009043:Motor Activity / Q000502:physiology*; D053594:Myeloid Differentiation Factor 88 / Q000172:deficiency*; D053764:Presenilin-1 / Q000235:genetics; D011597:Psychomotor Performance / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*; D013997:Time Factors
chemical_list: D016564:Amyloid beta-Protein Precursor; C507780:Myd88 protein, mouse; D053594:Myeloid Differentiation Factor 88; C508853:PSEN1 protein, human; D053764:Presenilin-1