Differential effects of aging and insulin-like growth factor-1 on synapses in CA1 of rat hippocampus

Lei Shi, Martha Constance Linville, Elizabeth Tucker, William Edmund Sonntag, Judy Karen Brunso-Bechtold

Research output: Contribution to journalArticle

Abstract

Aging-related impairments of learning and memory can be ameliorated by 28 days of intracerebroventricular (icv) infusion of insulin-like growth factor-1 (IGF-1) in old rats. The present study investigated whether there is an aging-related synaptic decline in the stratum radiatum of hippocampal CA1 and whether IGF-1 can ameliorate that decline. Five young (4 months), five middle-aged (18 months) and five old (29 months) Fischer 344xBrown Norway rats received saline infusion; five old (29 months) rats received IGF-1 infusion for 28 days preceding sacrifice. Pyramidal neurons, total synaptic profiles as well as synaptic profiles in multiple spine bouton (MSB) complexes in CA1 were quantified stereologically with the physical disector technique and the postsynaptic density (PSD) length was determined as well. The results indicated a decrease of total synapses between middle and old age but a maintenance of PSD length and MSB synapses throughout life. IGF-1 infusion in old rats did not reverse the aging-related decline in total synapses but did increase PSD length and the number of MSB synapses. These changes in synaptic configurations are morphological correlates of enhanced synaptic efficacy. Thus, aging and IGF-1 affect different, but complementary, aspects of synapses in hippocampal CA1.

Original languageEnglish (US)
Pages (from-to)571-577
Number of pages7
JournalCerebral Cortex
Volume15
Issue number5
DOIs
StatePublished - May 2005
Externally publishedYes

Fingerprint

Somatomedins
Synapses
Hippocampus
Post-Synaptic Density
Spine
Intraventricular Infusions
Hippocampal CA1 Region
Pyramidal Cells
Maintenance
Learning

Keywords

  • MSB complex
  • Plasticity
  • PSD length
  • Quantitative EM
  • Stereology

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Differential effects of aging and insulin-like growth factor-1 on synapses in CA1 of rat hippocampus. / Shi, Lei; Linville, Martha Constance; Tucker, Elizabeth; Sonntag, William Edmund; Brunso-Bechtold, Judy Karen.

In: Cerebral Cortex, Vol. 15, No. 5, 05.2005, p. 571-577.

Research output: Contribution to journalArticle

Shi, Lei ; Linville, Martha Constance ; Tucker, Elizabeth ; Sonntag, William Edmund ; Brunso-Bechtold, Judy Karen. / Differential effects of aging and insulin-like growth factor-1 on synapses in CA1 of rat hippocampus. In: Cerebral Cortex. 2005 ; Vol. 15, No. 5. pp. 571-577.
@article{44687f6daeeb4f8988f89a5cd48085de,
title = "Differential effects of aging and insulin-like growth factor-1 on synapses in CA1 of rat hippocampus",
abstract = "Aging-related impairments of learning and memory can be ameliorated by 28 days of intracerebroventricular (icv) infusion of insulin-like growth factor-1 (IGF-1) in old rats. The present study investigated whether there is an aging-related synaptic decline in the stratum radiatum of hippocampal CA1 and whether IGF-1 can ameliorate that decline. Five young (4 months), five middle-aged (18 months) and five old (29 months) Fischer 344xBrown Norway rats received saline infusion; five old (29 months) rats received IGF-1 infusion for 28 days preceding sacrifice. Pyramidal neurons, total synaptic profiles as well as synaptic profiles in multiple spine bouton (MSB) complexes in CA1 were quantified stereologically with the physical disector technique and the postsynaptic density (PSD) length was determined as well. The results indicated a decrease of total synapses between middle and old age but a maintenance of PSD length and MSB synapses throughout life. IGF-1 infusion in old rats did not reverse the aging-related decline in total synapses but did increase PSD length and the number of MSB synapses. These changes in synaptic configurations are morphological correlates of enhanced synaptic efficacy. Thus, aging and IGF-1 affect different, but complementary, aspects of synapses in hippocampal CA1.",
keywords = "MSB complex, Plasticity, PSD length, Quantitative EM, Stereology",
author = "Lei Shi and Linville, {Martha Constance} and Elizabeth Tucker and Sonntag, {William Edmund} and Brunso-Bechtold, {Judy Karen}",
year = "2005",
month = "5",
doi = "10.1093/cercor/bhh158",
language = "English (US)",
volume = "15",
pages = "571--577",
journal = "Cerebral Cortex",
issn = "1047-3211",
publisher = "Oxford University Press",
number = "5",

}

TY - JOUR

T1 - Differential effects of aging and insulin-like growth factor-1 on synapses in CA1 of rat hippocampus

AU - Shi, Lei

AU - Linville, Martha Constance

AU - Tucker, Elizabeth

AU - Sonntag, William Edmund

AU - Brunso-Bechtold, Judy Karen

PY - 2005/5

Y1 - 2005/5

N2 - Aging-related impairments of learning and memory can be ameliorated by 28 days of intracerebroventricular (icv) infusion of insulin-like growth factor-1 (IGF-1) in old rats. The present study investigated whether there is an aging-related synaptic decline in the stratum radiatum of hippocampal CA1 and whether IGF-1 can ameliorate that decline. Five young (4 months), five middle-aged (18 months) and five old (29 months) Fischer 344xBrown Norway rats received saline infusion; five old (29 months) rats received IGF-1 infusion for 28 days preceding sacrifice. Pyramidal neurons, total synaptic profiles as well as synaptic profiles in multiple spine bouton (MSB) complexes in CA1 were quantified stereologically with the physical disector technique and the postsynaptic density (PSD) length was determined as well. The results indicated a decrease of total synapses between middle and old age but a maintenance of PSD length and MSB synapses throughout life. IGF-1 infusion in old rats did not reverse the aging-related decline in total synapses but did increase PSD length and the number of MSB synapses. These changes in synaptic configurations are morphological correlates of enhanced synaptic efficacy. Thus, aging and IGF-1 affect different, but complementary, aspects of synapses in hippocampal CA1.

AB - Aging-related impairments of learning and memory can be ameliorated by 28 days of intracerebroventricular (icv) infusion of insulin-like growth factor-1 (IGF-1) in old rats. The present study investigated whether there is an aging-related synaptic decline in the stratum radiatum of hippocampal CA1 and whether IGF-1 can ameliorate that decline. Five young (4 months), five middle-aged (18 months) and five old (29 months) Fischer 344xBrown Norway rats received saline infusion; five old (29 months) rats received IGF-1 infusion for 28 days preceding sacrifice. Pyramidal neurons, total synaptic profiles as well as synaptic profiles in multiple spine bouton (MSB) complexes in CA1 were quantified stereologically with the physical disector technique and the postsynaptic density (PSD) length was determined as well. The results indicated a decrease of total synapses between middle and old age but a maintenance of PSD length and MSB synapses throughout life. IGF-1 infusion in old rats did not reverse the aging-related decline in total synapses but did increase PSD length and the number of MSB synapses. These changes in synaptic configurations are morphological correlates of enhanced synaptic efficacy. Thus, aging and IGF-1 affect different, but complementary, aspects of synapses in hippocampal CA1.

KW - MSB complex

KW - Plasticity

KW - PSD length

KW - Quantitative EM

KW - Stereology

UR - http://www.scopus.com/inward/record.url?scp=14244251413&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=14244251413&partnerID=8YFLogxK

U2 - 10.1093/cercor/bhh158

DO - 10.1093/cercor/bhh158

M3 - Article

VL - 15

SP - 571

EP - 577

JO - Cerebral Cortex

JF - Cerebral Cortex

SN - 1047-3211

IS - 5

ER -