Long-Term Regulation of Neuronal High-Affinity Glutamate and Glutamine Uptake In Aplysia

Authors

J Levenson, University of Houston, Department of Biology and Biochemistry, 4800 Calhoun Road, Houston, TX 77204-5513
S Endo, University of Houston, Department of Biology and Biochemistry, 4800 Calhoun Road, Houston, TX 77204-5513
L S. Kategaya, University of Houston, Department of Biology and Biochemistry, 4800 Calhoun Road, Houston, TX 77204-5513
R I. Fernandez, University of Houston, Department of Biology and Biochemistry, 4800 Calhoun Road, Houston, TX 77204-5513
D G. Brabham, University of Houston, Department of Biology and Biochemistry, 4800 Calhoun Road, Houston, TX 77204-5513
J Chin, Department of Neurobiology and Anatomy, University of Texas, Houston Medical School, Houston, TX 77225
J H. Byrne, Department of Neurobiology and Anatomy, University of Texas, Houston Medical School, Houston, TX 77225
A Eskin, University of Houston, Department of Biology and Biochemistry, 4800 Calhoun Road, Houston, TX 77204-5513

Language

English

Publication Date

11-7-2000

Journal

Proceedings of the National Academy of Sciences of the United States of America

DOI

10.1073/pnas.220256497

PMID

11050153

PMCID

PMC18854

PubMedCentral® Posted Date

October 2000

PubMedCentral® Full Text Version

Post-print

Abstract

An increase in transmitter release accompanying long-term sensitization and facilitation occurs at the glutamatergic sensorimotor synapse of Aplysia. We report that a long-term increase in neuronal Glu uptake also accompanies long-term sensitization. Synaptosomes from pleural-pedal ganglia exhibited sodium-dependent, high-affinity Glu transport. Different treatments that induce long-term enhancement of the siphon-withdrawal reflex, or long-term synaptic facilitation increased Glu uptake. Moreover, 5-hydroxytryptamine, a treatment that induces long-term facilitation, also produced a long-term increase in Glu uptake in cultures of sensory neurons. The mechanism for the increase in uptake is an increase in the V(max) of transport. The long-term increase in Glu uptake appeared to be dependent on mRNA and protein synthesis, and transport through the Golgi, because 5,6-dichlorobenzimidazole riboside, emetine, and brefeldin A inhibited the increase in Glu uptake. Also, injection of emetine and 5,6-dichlorobenzimidazole into Aplysia prevented long-term sensitization. Synthesis of Glu itself may be regulated during long-term sensitization because the same treatments that produced an increase in Glu uptake also produced a parallel increase in Gln uptake. These results suggest that coordinated regulation of a number of different processes may be required to establish or maintain long-term synaptic facilitation.

Keywords

Animals, Aplysia, Carrier Proteins, Glutamic Acid, Glutamine, Neurons, Time Factors

Published Open-Access

yes

Recommended Citation

Levenson, J; Endo, S; Kategaya, L S.; et al., "Long-Term Regulation of Neuronal High-Affinity Glutamate and Glutamine Uptake In Aplysia" (2000). Faculty, Staff and Student Publications. 19.
https://digitalcommons.library.tmc.edu/uthmed_docs/19