PMID- 24687840
OWN - NLM
STAT- MEDLINE
DCOM- 20150221
LR  - 20140616
IS  - 1097-4547 (Electronic)
IS  - 0360-4012 (Linking)
VI  - 92
IP  - 8
DP  - 2014 Aug
TI  - Liquid diet induces memory impairment accompanied by a decreased number of 
      hippocampal neurons in mice.
PG  - 1010-7
LID - 10.1002/jnr.23383 [doi]
AB  - It is suggested that masticatory dysfunction affects the central nervous system; 
      however, the underlying mechanism remains unknown. Brain-derived neurotrophic 
      factor (BDNF) and its receptor, TrkB, are known to play important roles in memory 
      and learning. In this study, we examined the effects of mastication on memory, 
      the expression levels of BDNF and TrkB, and the number of neurons in the 
      hippocampus of mice. Male C57 BL/6J mice (3 weeks old) were randomly divided into 
      the control group (N = 7) fed chow pellets and the experimental group (N = 7) fed 
      a liquid diet, which reduces mastication during eating. At 14 weeks of age, we 
      performed a passive avoidance test and found that memory and learning ability 
      were impaired in the experimental group compared with the control group. After 
      the behavioral experiment, brains were harvested and analyzed morphologically and 
      biochemically. In the hippocampus of the experimental group, the expression 
      levels of BDNF were significantly higher, whereas those of TrkB were lower than 
      those of the control group. In the cerebral cortex, these levels remained 
      unchanged between the two groups. The ratio of phospho-p44/42 ERK/pan ERK, a 
      downstream molecule of BDNF/TrkB signaling, in the experimental group was 
      significantly lower than that of the control group in the cortex and hippocampus. 
      The number of pyramidal neurons in the hippocampus was lower in the experimental 
      group than in the control group. These findings suggest that reduced mastication 
      induced by a liquid diet in early childhood may impair memory and learning 
      ability, accompanied by neuronal loss in the hippocampus.
CI  - (c) 2014 Wiley Periodicals, Inc.
FAU - Okihara, Hidemasa
AU  - Okihara H
AD  - Department of Biochemistry, Graduate School of Medical Sciences, Nagoya City 
      University, Nagoya, Japan; Department of Orthodontic Science, Oral Health 
      Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and 
      Dental University, Tokyo, Japan.
FAU - Ito, Jin-Ichi
AU  - Ito J
FAU - Kokai, Satoshi
AU  - Kokai S
FAU - Ishida, Takayoshi
AU  - Ishida T
FAU - Hiranuma, Maya
AU  - Hiranuma M
FAU - Kato, Chiho
AU  - Kato C
FAU - Yabushita, Tadachika
AU  - Yabushita T
FAU - Ishida, Kazuto
AU  - Ishida K
FAU - Ono, Takashi
AU  - Ono T
FAU - Michikawa, Makoto
AU  - Michikawa M
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20140331
PL  - United States
TA  - J Neurosci Res
JT  - Journal of neuroscience research
JID - 7600111
RN  - 0 (Brain-Derived Neurotrophic Factor)
RN  - EC 2.7.10.1 (Receptor, trkB)
SB  - IM
MH  - Animals
MH  - Avoidance Learning/physiology
MH  - Behavior, Animal/physiology
MH  - Brain-Derived Neurotrophic Factor/metabolism
MH  - Cell Count
MH  - *Diet
MH  - Hippocampus/*cytology/metabolism
MH  - Male
MH  - Mastication/*physiology
MH  - Memory Disorders/*metabolism
MH  - Mice
MH  - Mice, Inbred C57BL
MH  - Neurons/*cytology/metabolism
MH  - Receptor, trkB/metabolism
OTO - NOTNLM
OT  - hippocampal neuron
OT  - mastication
OT  - memory impairment
OT  - soft diet
EDAT- 2014/04/02 06:00
MHDA- 2015/02/24 06:00
CRDT- 2014/04/02 06:00
PHST- 2013/10/15 00:00 [received]
PHST- 2014/02/19 00:00 [revised]
PHST- 2014/02/19 00:00 [accepted]
PHST- 2014/04/02 06:00 [entrez]
PHST- 2014/04/02 06:00 [pubmed]
PHST- 2015/02/24 06:00 [medline]
AID - 10.1002/jnr.23383 [doi]
PST - ppublish
SO  - J Neurosci Res. 2014 Aug;92(8):1010-7. doi: 10.1002/jnr.23383. Epub 2014 Mar 31.