Activation Of Nmda Receptors In Hippocampal Area Ca1 By Low And High-frequency Orthodromic Stimulation And Their Contribution To Induction Of Long-term Potentiation

Title

Activation Of Nmda Receptors In Hippocampal Area Ca1 By Low And High-frequency Orthodromic Stimulation And Their Contribution To Induction Of Long-term Potentiation

Creator

Grover L M; Teyler T J

Publisher

Synapse

Date

1994
1994-01

Description

N-methyl-D-aspartate (NMDA) receptors are important in many instances of synaptic plasticity. In hippocampal area CA1, long-term potentiation (LTP) can be induced by both NMDA receptor-dependent and -independent mechanisms. Using intracellular recordings and single-electrode voltage clamp, we isolated and characterized NMDA receptor-mediated synaptic responses. NMDA receptor-mediated responses evoked by low frequency orthodromic stimulation were inhibited in a dose-dependent manner by the competitive antagonist D,L-2-amino-5-phosphonovaleric acid (APV). High frequency (tetanic) stimulation, which facilitates synaptic release of glutamate, failed to overcome the blockade of NMDA receptors by APV. Using extracellular recordings of field potentials, we studied the contribution of NMDA receptors to LTP induced by different patterns of tetanic stimulation. LTP was inhibited in a dose-dependent manner by APV, but was more sensitive to APV than were NMDA receptor-mediated synaptic responses. This most likely reflects a threshold for NMDA receptor activation in LTP induction. A component of LTP that resisted blockade by APV was induced by high (200 Hz), but not low (25 Hz), frequency tetanization. This NMDA receptor-independent component of LTP persisted for > 4 hours and accounted for approximately half the potentiation induced by 200 Hz tetanization. Procedures necessary to induce LTP at the Schaffer collateral/commissural synapses in area CA1 by both NMDA receptor-dependent and -independent mechanisms are now well characterized. Using the same neuronal population, it will be possible to ask if processes involved in the maintenance of LTP are shared even when LTP is induced through two different mechanisms. (C) 1994 Wiley-Liss, Inc.

Subject

2-amino-5-phosphonovaleric acid; amino-acid receptors; cells; clamp; dentate gyrus; hippocampus; invitro rat hippocampus; kitten visual-cortex; n-methyl-d-aspartate receptor; Neurosciences & Neurology; pyramidal; responses; single-electrode voltage; slices; spinal-cord neurons; stimulation; synaptic plasticity; synaptic transmission; tetanic; time course

Format

Journal Article or Conference Abstract Publication

Search for Full-text

Users with a NEOMED Library login can search for full-text journal articles at the following url: https://libraryguides.neomed.edu/home

Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

Pages

66-75

Issue

1

Volume

16

Citation

Grover L M; Teyler T J, “Activation Of Nmda Receptors In Hippocampal Area Ca1 By Low And High-frequency Orthodromic Stimulation And Their Contribution To Induction Of Long-term Potentiation,” NEOMED Bibliography Database, accessed May 6, 2021, https://neomed.omeka.net/items/show/10017.

Social Bookmarking