Ovariectomy combined with amyloid β1-42 impairs memory by decreasing acetylcholine release and α7nAChR expression without induction of apoptosis in the hippocampus CA1 neurons of rats

Katsunori Iwasaki, Izzettin Hatip-Al-Khatib, Nobuaki Egashira, Yuki Akiyoshi, Takashi Arai, Kenichi Mishima, Yuki Takagaki, Keiichiro Inui, Michihiro Fujiwara

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

In this study, the effect of ovariectomy and amyloid P1-42 (Aβ1-42)on eight-armed radial maze performance, acetylcholine (ACh) release, α7nACh receptor (α7nAChR), glyceraldehyde 3-phosphate dehydrogenase (GAPDH) expression, and apoptosis of CA1 neurons in the dorsal hippocampus were investigated in rat. The results showed that the dorsal hippocampus of sham rats contains 136.7 ± 16.7 to 160.4 ± 21.1 fmol/μl ACh, and respective 201 ± 22.9 and 416.6 ± 66.3 expression of mRNA for α7nAChR and GAPDH. Ovariectomy alone, after 4 weeks, did not impair memory, and neither induced apoptosis nor changed the basal ACh release. On the other hand, Aβ1-42 (600 pmol/10 μl/ body/day i.c.v. for 7 days) impaired memory, an effect characterized by increased error choices and reduced (50-59%) ACh release, but only with slight apoptosis. Moreover, ovariectomy combined with Aβ1-42 induced memory impairment characterized by decreased numbers of correct choices and increased numbers of errors. This effect was accompanied by a decrease of the basal ACh level (67%), α7nAChR mRNA expression (52%) and α7nAChR/GAPDH ratio (44%) without induction of apoptosis in the dorsal hippocampus. The high K+-evoked ACh release was not altered in ovariectomized rats, but was decreased by Aβ1-42 (43%) and ovariectomy + Aβ1-42 (80%). These results suggest that ovariectomy-induced hormonal deprivation after 4 weeks, when accompanied by Aβ1-42 accumulation in the dorsal hippocampus, could impair memory by decreasing ACh release and α7nAChR expression without inducing apoptosis in the CA1 field of the dorsal hippocampus.

Original languageEnglish
Pages (from-to)299-309
Number of pages11
JournalNeurotoxicity Research
Volume6
Issue number4
DOIs
Publication statusPublished - Dec 1 2004
Externally publishedYes

Fingerprint

Ovariectomy
Amyloid
Acetylcholine
Neurons
Rats
Hippocampus
Apoptosis
Data storage equipment
Glyceraldehyde-3-Phosphate Dehydrogenases
Hippocampal CA1 Region
Messenger RNA

All Science Journal Classification (ASJC) codes

  • Neuroscience(all)
  • Toxicology

Cite this

Ovariectomy combined with amyloid β1-42 impairs memory by decreasing acetylcholine release and α7nAChR expression without induction of apoptosis in the hippocampus CA1 neurons of rats. / Iwasaki, Katsunori; Hatip-Al-Khatib, Izzettin; Egashira, Nobuaki; Akiyoshi, Yuki; Arai, Takashi; Mishima, Kenichi; Takagaki, Yuki; Inui, Keiichiro; Fujiwara, Michihiro.

In: Neurotoxicity Research, Vol. 6, No. 4, 01.12.2004, p. 299-309.

Research output: Contribution to journalArticle

Iwasaki, Katsunori ; Hatip-Al-Khatib, Izzettin ; Egashira, Nobuaki ; Akiyoshi, Yuki ; Arai, Takashi ; Mishima, Kenichi ; Takagaki, Yuki ; Inui, Keiichiro ; Fujiwara, Michihiro. / Ovariectomy combined with amyloid β1-42 impairs memory by decreasing acetylcholine release and α7nAChR expression without induction of apoptosis in the hippocampus CA1 neurons of rats. In: Neurotoxicity Research. 2004 ; Vol. 6, No. 4. pp. 299-309.
@article{27220aaa28564f4c846dcf6ffdea94d7,
title = "Ovariectomy combined with amyloid β1-42 impairs memory by decreasing acetylcholine release and α7nAChR expression without induction of apoptosis in the hippocampus CA1 neurons of rats",
abstract = "In this study, the effect of ovariectomy and amyloid P1-42 (Aβ1-42)on eight-armed radial maze performance, acetylcholine (ACh) release, α7nACh receptor (α7nAChR), glyceraldehyde 3-phosphate dehydrogenase (GAPDH) expression, and apoptosis of CA1 neurons in the dorsal hippocampus were investigated in rat. The results showed that the dorsal hippocampus of sham rats contains 136.7 ± 16.7 to 160.4 ± 21.1 fmol/μl ACh, and respective 201 ± 22.9 and 416.6 ± 66.3 expression of mRNA for α7nAChR and GAPDH. Ovariectomy alone, after 4 weeks, did not impair memory, and neither induced apoptosis nor changed the basal ACh release. On the other hand, Aβ1-42 (600 pmol/10 μl/ body/day i.c.v. for 7 days) impaired memory, an effect characterized by increased error choices and reduced (50-59{\%}) ACh release, but only with slight apoptosis. Moreover, ovariectomy combined with Aβ1-42 induced memory impairment characterized by decreased numbers of correct choices and increased numbers of errors. This effect was accompanied by a decrease of the basal ACh level (67{\%}), α7nAChR mRNA expression (52{\%}) and α7nAChR/GAPDH ratio (44{\%}) without induction of apoptosis in the dorsal hippocampus. The high K+-evoked ACh release was not altered in ovariectomized rats, but was decreased by Aβ1-42 (43{\%}) and ovariectomy + Aβ1-42 (80{\%}). These results suggest that ovariectomy-induced hormonal deprivation after 4 weeks, when accompanied by Aβ1-42 accumulation in the dorsal hippocampus, could impair memory by decreasing ACh release and α7nAChR expression without inducing apoptosis in the CA1 field of the dorsal hippocampus.",
author = "Katsunori Iwasaki and Izzettin Hatip-Al-Khatib and Nobuaki Egashira and Yuki Akiyoshi and Takashi Arai and Kenichi Mishima and Yuki Takagaki and Keiichiro Inui and Michihiro Fujiwara",
year = "2004",
month = "12",
day = "1",
doi = "10.1007/BF03033440",
language = "English",
volume = "6",
pages = "299--309",
journal = "Neurotoxicity Research",
issn = "1029-8428",
publisher = "Springer New York",
number = "4",

}

TY - JOUR

T1 - Ovariectomy combined with amyloid β1-42 impairs memory by decreasing acetylcholine release and α7nAChR expression without induction of apoptosis in the hippocampus CA1 neurons of rats

AU - Iwasaki, Katsunori

AU - Hatip-Al-Khatib, Izzettin

AU - Egashira, Nobuaki

AU - Akiyoshi, Yuki

AU - Arai, Takashi

AU - Mishima, Kenichi

AU - Takagaki, Yuki

AU - Inui, Keiichiro

AU - Fujiwara, Michihiro

PY - 2004/12/1

Y1 - 2004/12/1

N2 - In this study, the effect of ovariectomy and amyloid P1-42 (Aβ1-42)on eight-armed radial maze performance, acetylcholine (ACh) release, α7nACh receptor (α7nAChR), glyceraldehyde 3-phosphate dehydrogenase (GAPDH) expression, and apoptosis of CA1 neurons in the dorsal hippocampus were investigated in rat. The results showed that the dorsal hippocampus of sham rats contains 136.7 ± 16.7 to 160.4 ± 21.1 fmol/μl ACh, and respective 201 ± 22.9 and 416.6 ± 66.3 expression of mRNA for α7nAChR and GAPDH. Ovariectomy alone, after 4 weeks, did not impair memory, and neither induced apoptosis nor changed the basal ACh release. On the other hand, Aβ1-42 (600 pmol/10 μl/ body/day i.c.v. for 7 days) impaired memory, an effect characterized by increased error choices and reduced (50-59%) ACh release, but only with slight apoptosis. Moreover, ovariectomy combined with Aβ1-42 induced memory impairment characterized by decreased numbers of correct choices and increased numbers of errors. This effect was accompanied by a decrease of the basal ACh level (67%), α7nAChR mRNA expression (52%) and α7nAChR/GAPDH ratio (44%) without induction of apoptosis in the dorsal hippocampus. The high K+-evoked ACh release was not altered in ovariectomized rats, but was decreased by Aβ1-42 (43%) and ovariectomy + Aβ1-42 (80%). These results suggest that ovariectomy-induced hormonal deprivation after 4 weeks, when accompanied by Aβ1-42 accumulation in the dorsal hippocampus, could impair memory by decreasing ACh release and α7nAChR expression without inducing apoptosis in the CA1 field of the dorsal hippocampus.

AB - In this study, the effect of ovariectomy and amyloid P1-42 (Aβ1-42)on eight-armed radial maze performance, acetylcholine (ACh) release, α7nACh receptor (α7nAChR), glyceraldehyde 3-phosphate dehydrogenase (GAPDH) expression, and apoptosis of CA1 neurons in the dorsal hippocampus were investigated in rat. The results showed that the dorsal hippocampus of sham rats contains 136.7 ± 16.7 to 160.4 ± 21.1 fmol/μl ACh, and respective 201 ± 22.9 and 416.6 ± 66.3 expression of mRNA for α7nAChR and GAPDH. Ovariectomy alone, after 4 weeks, did not impair memory, and neither induced apoptosis nor changed the basal ACh release. On the other hand, Aβ1-42 (600 pmol/10 μl/ body/day i.c.v. for 7 days) impaired memory, an effect characterized by increased error choices and reduced (50-59%) ACh release, but only with slight apoptosis. Moreover, ovariectomy combined with Aβ1-42 induced memory impairment characterized by decreased numbers of correct choices and increased numbers of errors. This effect was accompanied by a decrease of the basal ACh level (67%), α7nAChR mRNA expression (52%) and α7nAChR/GAPDH ratio (44%) without induction of apoptosis in the dorsal hippocampus. The high K+-evoked ACh release was not altered in ovariectomized rats, but was decreased by Aβ1-42 (43%) and ovariectomy + Aβ1-42 (80%). These results suggest that ovariectomy-induced hormonal deprivation after 4 weeks, when accompanied by Aβ1-42 accumulation in the dorsal hippocampus, could impair memory by decreasing ACh release and α7nAChR expression without inducing apoptosis in the CA1 field of the dorsal hippocampus.

UR - http://www.scopus.com/inward/record.url?scp=21644480293&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=21644480293&partnerID=8YFLogxK

U2 - 10.1007/BF03033440

DO - 10.1007/BF03033440

M3 - Article

C2 - 15545013

AN - SCOPUS:21644480293

VL - 6

SP - 299

EP - 309

JO - Neurotoxicity Research

JF - Neurotoxicity Research

SN - 1029-8428

IS - 4

ER -