Release of endogenous excitatory amino acids from turtle photoreceptors

David R. Copenhagen, Craig Jahr

Research output: Contribution to journalArticle

206 Citations (Scopus)

Abstract

RESPONSES to light are transmitted from photoreceptors to second-order retinal neurons by chemical synapses that may use an excitatory amino acid (EAA) as the neurotransmitter. This hypothesis is based primarily on the pharmacological actions of EAA agonists and antagonists on the membrane potentials and light responses of second-order neurons. But the release of endogenous EAAs, which is a critical criterion for the identification of EAAs as transmitters, has not been demonstrated. Here we report the use of outside-out membrane patches excised from rat hippocampal neurons to detect the release of EAAs from synaptic terminals of isolated turtle photoreceptors. Electrical stimulation of or application of lanthanum chloride to photoreceptors induced an increase in the frequency of opening of 50-pS channels in the patches. These channels were identified as the class of glutamate-activated channels that are also gated by aspartate and NMDA (N-methyl-D-aspartate). In several photoreceptor-patch pairs, spontaneous channel activity was observed near the synaptic terminals. These results provide strong evidence to support the hypothesis that both rods and cones of the turtle use an EAA as their neurotransmitter.

Original languageEnglish (US)
Pages (from-to)536-539
Number of pages4
JournalNature
Volume341
Issue number6242
StatePublished - 1989

Fingerprint

Excitatory Amino Acids
Turtles
Presynaptic Terminals
Neurotransmitter Agents
Retinal Neurons
Excitatory Amino Acid Agonists
Neurons
Light
Excitatory Amino Acid Antagonists
Vertebrate Photoreceptor Cells
N-Methylaspartate
Aspartic Acid
Membrane Potentials
Synapses
Electric Stimulation
Glutamic Acid
Pharmacology
Membranes
lanthanum chloride

ASJC Scopus subject areas

  • General

Cite this

Copenhagen, D. R., & Jahr, C. (1989). Release of endogenous excitatory amino acids from turtle photoreceptors. Nature, 341(6242), 536-539.

Release of endogenous excitatory amino acids from turtle photoreceptors. / Copenhagen, David R.; Jahr, Craig.

In: Nature, Vol. 341, No. 6242, 1989, p. 536-539.

Research output: Contribution to journalArticle

Copenhagen, DR & Jahr, C 1989, 'Release of endogenous excitatory amino acids from turtle photoreceptors', Nature, vol. 341, no. 6242, pp. 536-539.
Copenhagen, David R. ; Jahr, Craig. / Release of endogenous excitatory amino acids from turtle photoreceptors. In: Nature. 1989 ; Vol. 341, No. 6242. pp. 536-539.
@article{0afc4e717852495c800529c176ec3bc4,
title = "Release of endogenous excitatory amino acids from turtle photoreceptors",
abstract = "RESPONSES to light are transmitted from photoreceptors to second-order retinal neurons by chemical synapses that may use an excitatory amino acid (EAA) as the neurotransmitter. This hypothesis is based primarily on the pharmacological actions of EAA agonists and antagonists on the membrane potentials and light responses of second-order neurons. But the release of endogenous EAAs, which is a critical criterion for the identification of EAAs as transmitters, has not been demonstrated. Here we report the use of outside-out membrane patches excised from rat hippocampal neurons to detect the release of EAAs from synaptic terminals of isolated turtle photoreceptors. Electrical stimulation of or application of lanthanum chloride to photoreceptors induced an increase in the frequency of opening of 50-pS channels in the patches. These channels were identified as the class of glutamate-activated channels that are also gated by aspartate and NMDA (N-methyl-D-aspartate). In several photoreceptor-patch pairs, spontaneous channel activity was observed near the synaptic terminals. These results provide strong evidence to support the hypothesis that both rods and cones of the turtle use an EAA as their neurotransmitter.",
author = "Copenhagen, {David R.} and Craig Jahr",
year = "1989",
language = "English (US)",
volume = "341",
pages = "536--539",
journal = "Nature",
issn = "0028-0836",
publisher = "Nature Publishing Group",
number = "6242",

}

TY - JOUR

T1 - Release of endogenous excitatory amino acids from turtle photoreceptors

AU - Copenhagen, David R.

AU - Jahr, Craig

PY - 1989

Y1 - 1989

N2 - RESPONSES to light are transmitted from photoreceptors to second-order retinal neurons by chemical synapses that may use an excitatory amino acid (EAA) as the neurotransmitter. This hypothesis is based primarily on the pharmacological actions of EAA agonists and antagonists on the membrane potentials and light responses of second-order neurons. But the release of endogenous EAAs, which is a critical criterion for the identification of EAAs as transmitters, has not been demonstrated. Here we report the use of outside-out membrane patches excised from rat hippocampal neurons to detect the release of EAAs from synaptic terminals of isolated turtle photoreceptors. Electrical stimulation of or application of lanthanum chloride to photoreceptors induced an increase in the frequency of opening of 50-pS channels in the patches. These channels were identified as the class of glutamate-activated channels that are also gated by aspartate and NMDA (N-methyl-D-aspartate). In several photoreceptor-patch pairs, spontaneous channel activity was observed near the synaptic terminals. These results provide strong evidence to support the hypothesis that both rods and cones of the turtle use an EAA as their neurotransmitter.

AB - RESPONSES to light are transmitted from photoreceptors to second-order retinal neurons by chemical synapses that may use an excitatory amino acid (EAA) as the neurotransmitter. This hypothesis is based primarily on the pharmacological actions of EAA agonists and antagonists on the membrane potentials and light responses of second-order neurons. But the release of endogenous EAAs, which is a critical criterion for the identification of EAAs as transmitters, has not been demonstrated. Here we report the use of outside-out membrane patches excised from rat hippocampal neurons to detect the release of EAAs from synaptic terminals of isolated turtle photoreceptors. Electrical stimulation of or application of lanthanum chloride to photoreceptors induced an increase in the frequency of opening of 50-pS channels in the patches. These channels were identified as the class of glutamate-activated channels that are also gated by aspartate and NMDA (N-methyl-D-aspartate). In several photoreceptor-patch pairs, spontaneous channel activity was observed near the synaptic terminals. These results provide strong evidence to support the hypothesis that both rods and cones of the turtle use an EAA as their neurotransmitter.

UR - http://www.scopus.com/inward/record.url?scp=0024423904&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0024423904&partnerID=8YFLogxK

M3 - Article

C2 - 2477707

AN - SCOPUS:0024423904

VL - 341

SP - 536

EP - 539

JO - Nature

JF - Nature

SN - 0028-0836

IS - 6242

ER -