Decreased glutamate release correlates with elevated dynorphin content in the hippocampus of aged rats with spatial learning deficits.

W. Q. Zhang, W. R. Mundy, L. Thai, P. M. Hudson, Michela Gallagher, H. A. Tilson, J. S. Hong

Research output: Contribution to journalArticle

Abstract

The effects of aging on extracellular glutamate and tissue dynorphin content in the hippocampus were examined in Fischer-344 rats. Young adult (4-month-old) and aged (24-month-old) rats were trained to find a hidden platform in the Morris water task. Aged rats were unable to acquire the spatial learning task as rapidly as young controls. Following behavioral testing, an in vivo microdialysis perfusion method was used to determine extracellular glutamate levels in the hippocampus. There was a 25-35% reduction in extracellular glutamate concentration in both dorsal and ventral hippocampus of aged rats compared to young rats, in the absence of any change in tissue glutamate levels. Radioimmunoassay showed an increase in dynorphin A(1-8)-like immunoreactivity [DYN-A(1-8)LI] in both dorsal and ventral hippocampus, but not striatum, of aged rats. Immunocytochemistry indicated that this increase was localized to the dentate granule cells and mossy fibers. Furthermore, among the aged rats the increase in DYN-A(1-8)LI was inversely correlated with the decrease in extracellular glutamate. These results suggest that the disregulation of dynorphin observed in cognitively impaired aged rats is related to reduced excitatory transmission within the hippocampal formation.

Original languageEnglish (US)
Pages (from-to)391-397
Number of pages7
JournalHippocampus
Volume1
Issue number4
StatePublished - Oct 1991
Externally publishedYes

Fingerprint

Dynorphins
Glutamic Acid
Hippocampus
dynorphin (1-8)
Inbred F344 Rats
Microdialysis
Spatial Learning
Radioimmunoassay
Young Adult
Perfusion
Immunohistochemistry
Water

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

Zhang, W. Q., Mundy, W. R., Thai, L., Hudson, P. M., Gallagher, M., Tilson, H. A., & Hong, J. S. (1991). Decreased glutamate release correlates with elevated dynorphin content in the hippocampus of aged rats with spatial learning deficits. Hippocampus, 1(4), 391-397.

Decreased glutamate release correlates with elevated dynorphin content in the hippocampus of aged rats with spatial learning deficits. / Zhang, W. Q.; Mundy, W. R.; Thai, L.; Hudson, P. M.; Gallagher, Michela; Tilson, H. A.; Hong, J. S.

In: Hippocampus, Vol. 1, No. 4, 10.1991, p. 391-397.

Research output: Contribution to journalArticle

Zhang, W. Q. ; Mundy, W. R. ; Thai, L. ; Hudson, P. M. ; Gallagher, Michela ; Tilson, H. A. ; Hong, J. S. / Decreased glutamate release correlates with elevated dynorphin content in the hippocampus of aged rats with spatial learning deficits. In: Hippocampus. 1991 ; Vol. 1, No. 4. pp. 391-397.
@article{cd046425f1d54058be93e9ddc04301f7,
title = "Decreased glutamate release correlates with elevated dynorphin content in the hippocampus of aged rats with spatial learning deficits.",
abstract = "The effects of aging on extracellular glutamate and tissue dynorphin content in the hippocampus were examined in Fischer-344 rats. Young adult (4-month-old) and aged (24-month-old) rats were trained to find a hidden platform in the Morris water task. Aged rats were unable to acquire the spatial learning task as rapidly as young controls. Following behavioral testing, an in vivo microdialysis perfusion method was used to determine extracellular glutamate levels in the hippocampus. There was a 25-35{\%} reduction in extracellular glutamate concentration in both dorsal and ventral hippocampus of aged rats compared to young rats, in the absence of any change in tissue glutamate levels. Radioimmunoassay showed an increase in dynorphin A(1-8)-like immunoreactivity [DYN-A(1-8)LI] in both dorsal and ventral hippocampus, but not striatum, of aged rats. Immunocytochemistry indicated that this increase was localized to the dentate granule cells and mossy fibers. Furthermore, among the aged rats the increase in DYN-A(1-8)LI was inversely correlated with the decrease in extracellular glutamate. These results suggest that the disregulation of dynorphin observed in cognitively impaired aged rats is related to reduced excitatory transmission within the hippocampal formation.",
author = "Zhang, {W. Q.} and Mundy, {W. R.} and L. Thai and Hudson, {P. M.} and Michela Gallagher and Tilson, {H. A.} and Hong, {J. S.}",
year = "1991",
month = "10",
language = "English (US)",
volume = "1",
pages = "391--397",
journal = "Hippocampus",
issn = "1050-9631",
publisher = "Wiley-Liss Inc.",
number = "4",

}

TY - JOUR

T1 - Decreased glutamate release correlates with elevated dynorphin content in the hippocampus of aged rats with spatial learning deficits.

AU - Zhang, W. Q.

AU - Mundy, W. R.

AU - Thai, L.

AU - Hudson, P. M.

AU - Gallagher, Michela

AU - Tilson, H. A.

AU - Hong, J. S.

PY - 1991/10

Y1 - 1991/10

N2 - The effects of aging on extracellular glutamate and tissue dynorphin content in the hippocampus were examined in Fischer-344 rats. Young adult (4-month-old) and aged (24-month-old) rats were trained to find a hidden platform in the Morris water task. Aged rats were unable to acquire the spatial learning task as rapidly as young controls. Following behavioral testing, an in vivo microdialysis perfusion method was used to determine extracellular glutamate levels in the hippocampus. There was a 25-35% reduction in extracellular glutamate concentration in both dorsal and ventral hippocampus of aged rats compared to young rats, in the absence of any change in tissue glutamate levels. Radioimmunoassay showed an increase in dynorphin A(1-8)-like immunoreactivity [DYN-A(1-8)LI] in both dorsal and ventral hippocampus, but not striatum, of aged rats. Immunocytochemistry indicated that this increase was localized to the dentate granule cells and mossy fibers. Furthermore, among the aged rats the increase in DYN-A(1-8)LI was inversely correlated with the decrease in extracellular glutamate. These results suggest that the disregulation of dynorphin observed in cognitively impaired aged rats is related to reduced excitatory transmission within the hippocampal formation.

AB - The effects of aging on extracellular glutamate and tissue dynorphin content in the hippocampus were examined in Fischer-344 rats. Young adult (4-month-old) and aged (24-month-old) rats were trained to find a hidden platform in the Morris water task. Aged rats were unable to acquire the spatial learning task as rapidly as young controls. Following behavioral testing, an in vivo microdialysis perfusion method was used to determine extracellular glutamate levels in the hippocampus. There was a 25-35% reduction in extracellular glutamate concentration in both dorsal and ventral hippocampus of aged rats compared to young rats, in the absence of any change in tissue glutamate levels. Radioimmunoassay showed an increase in dynorphin A(1-8)-like immunoreactivity [DYN-A(1-8)LI] in both dorsal and ventral hippocampus, but not striatum, of aged rats. Immunocytochemistry indicated that this increase was localized to the dentate granule cells and mossy fibers. Furthermore, among the aged rats the increase in DYN-A(1-8)LI was inversely correlated with the decrease in extracellular glutamate. These results suggest that the disregulation of dynorphin observed in cognitively impaired aged rats is related to reduced excitatory transmission within the hippocampal formation.

UR - http://www.scopus.com/inward/record.url?scp=0026231035&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0026231035&partnerID=8YFLogxK

M3 - Article

VL - 1

SP - 391

EP - 397

JO - Hippocampus

JF - Hippocampus

SN - 1050-9631

IS - 4

ER -