QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

This Article Full Text Full Text (PDF) Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (31) Citing Articles via Google Scholar Google Scholar Articles by Ouanounou, A. Articles by Carlen, P. L. Search for Related Content PubMed PubMed Citation Articles by Ouanounou, A. Articles by Carlen, P. L.

 Previous Article  |  Next Article 

The Journal of Neuroscience, February 1, 1999, 19(3):906-915

Differential Modulation of Synaptic Transmission by Calcium Chelators in Young and Aged Hippocampal CA1 Neurons: Evidence for Altered Calcium Homeostasis in Aging

Aviv Ouanounou^{1, 2, 3, 4}, Liang Zhang^{1, 3}, Milton P. Charlton^{1, 2, 4}, and Peter L. Carlen^{1, 2, 3, 4}

¹ Playfair Neuroscience Unit, Toronto Hospital Research Institute, ² Medical Research Council Group on Nerve Cells and Synapses, and Departments of ³ Medicine (Neurology) and ⁴ Physiology, University of Toronto, Toronto, Ontario M5T 2S8, Canada

The effects of membrane-permeant Ca²⁺ chelators on field EPSPs (fEPSPs) were measured in the hippocampal CA1 region of brain slices from young (2-4 months) and old (24-27 months) Fischer 344 rats. BAPTA-AM depressed fEPSPs in young slices by up to 70% but enhanced fEPSPs by 30% in aged slices. EGTA-AM, with slower binding kinetics, did not affect fEPSPs from young slices but enhanced fEPSPs in aged slices. BAPTA derivatives with calcium dissociation constants (K_d) of 0.2-3.5 µM reduced or enhanced fEPSPs in young and aged slices, respectively, but 5',5'-dinitro BAPTA-AM (K_d of ~7000 µM) had no effect. Frequency facilitation of the fEPSPs occurred in young, but not in aged, slices, except when BAPTA-AM or EGTA-AM was perfused onto aged slices. The differential effects of BAPTA-AM in young and old slices were eliminated by perfusing with a low Ca²⁺-high Mg²⁺ saline or with the calcium blocker Co²⁺. These data suggest that intracellular Ca²⁺ regulation is altered and raised in aged neurons. Cell-permeant calcium buffers may be able to "ameliorate" deficits in synaptic transmission in the aged brain.

Key words: calcium chelator; BAPTA-AM; EGTA-AM; probenecid; hippocampus; field EPSP; frequency facilitation; synaptic transmission; aging

---

Copyright © 1999 Society for Neuroscience  0270-6474/99/193906-10$05.00/0

This article has been cited by other articles:

				G. F. Reis, M. B. Lee, A. S. Huang, and K. D. Parfitt Adenylate Cyclase-Mediated Forms of Neuronal Plasticity in Hippocampal Area CA1 Are Reduced With Aging J Neurophysiol, June 1, 2005; 93(6): 3381 - 3389. [Abstract] [Full Text] [PDF]

				X.-L. Zhang, L. Zhang, and P. L. Carlen Electrotonic coupling between stratum oriens interneurones in the intact in vitro mouse juvenile hippocampus J. Physiol., August 1, 2004; 558(3): 825 - 839. [Abstract] [Full Text] [PDF]

				O. Thibault, R. Hadley, and P. W. Landfield Elevated Postsynaptic [Ca2+]i and L-Type Calcium Channel Activity in Aged Hippocampal Neurons: Relationship to Impaired Synaptic Plasticity J. Neurosci., December 15, 2001; 21(24): 9744 - 9756. [Abstract] [Full Text] [PDF]

				A. Ouanonou, Y. Zhang, and L. Zhang Changes in the Calcium Dependence of Glutamate Transmission in the Hippocampal CA1 Region After Brief Hypoxia-Hypoglycemia J Neurophysiol, September 1, 1999; 82(3): 1147 - 1155. [Abstract] [Full Text] [PDF]

				G. F. Reis, M. B. Lee, A. S. Huang, and K. D. Parfitt Adenylate Cyclase-Mediated Forms of Neuronal Plasticity in Hippocampal Area CA1 Are Reduced With Aging J Neurophysiol, June 1, 2005; 93(6): 3381 - 3389. [Abstract] [Full Text] [PDF]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help