|
|
||||||||
The Journal of Neurophysiology Vol. 82 No. 3 September 1999, pp. 1477-1488
Copyright ©1999 by the American Physiological Society
Committee on Neurobiology and Department of Neurobiology, Pharmacology, and Physiology, University of Chicago, Chicago, Illinois 60637
Fox, Lyle E. and
Philip E. Lloyd.
Glutamate is a Fast Excitatory Transmitter at Some Buccal
Neuromuscular Synapses in Aplysia. J. Neurophysiol. 82: 1477-1488, 1999. Studies of the modulation
of synaptic transmission in buccal muscle of Aplysia
were limited because the conventional fast transmitter used by a number
of large buccal motor neurons was unknown. Most of the identified
buccal motor neurons are cholinergic because they synthesize
acetylcholine (ACh) and their excitatory junction potentials (EJPs) are
blocked by the cholinergic antagonist hexamethonium. However, three
large identified motor neurons (B3, B6, and B38) do not synthesize ACh
and their EJPs are not inhibited by hexamethonium. To identify the fast
excitatory transmitter used by these noncholinergic motor neurons, we
surveyed putative transmitters for their ability to evoke contractions.
Of the noncholinergic transmitters tested, glutamate was the most
effective at evoking contractions. The pharmacology of the putative
glutamate receptor is different from previously characterized glutamate
receptors in that glutamate agonists and antagonists previously used to classify glutamate receptors had little effect in this system. In
addition, glutamate itself was the most effective agent tested at
reducing EJPs evoked by the noncholinergic motor neurons presumably by
desensitizing glutamate receptors. Finally, immunocytology using an
antiserum raised to conjugated glutamate in parallel with intracellular
fills indicated that the varicose axons of these motor neurons were
glutamate-immunoreactive. Taken together, these results indicate that
the fast transmitter used by the noncholinergic neurons is almost
certainly glutamate itself. This information should help us understand
the role of transmitters and cotransmitters in the generation of
feeding behaviors in Aplysia.
This article has been cited by other articles:
![]() |
D. Hatakeyama, H. Aonuma, E. Ito, and K. Elekes Localization of Glutamate-like Immunoreactive Neurons in the Central and Peripheral Nervous System of the Adult and Developing Pond Snail, Lymnaea stagnalis Biol. Bull., October 1, 2007; 213(2): 172 - 186. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. Brunelli, P. Spano, S. Barlati, B. Guarneri, A. Barbon, R. Bresciani, and M. Pizzi Glutamatergic reinnervation through peripheral nerve graft dictates assembly of glutamatergic synapses at rat skeletal muscle PNAS, June 14, 2005; 102(24): 8752 - 8757. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. E. Fox and P. E. Lloyd Mechanisms Involved in Persistent Facilitation of Neuromuscular Synapses in Aplysia J Neurophysiol, April 1, 2002; 87(4): 2018 - 2030. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. J. H. Elliott and A. J. Susswein Comparative neuroethology of feeding control in molluscs J. Exp. Biol., April 1, 2002; 205(7): 877 - 896. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. E. Fox and P. E. Lloyd Evidence That Post-Tetanic Potentiation Is Mediated by Neuropeptide Release in Aplysia J Neurophysiol, December 1, 2001; 86(6): 2845 - 2855. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Matzner, Y. Gutfreund, and B. Hochner Neuromuscular System of the Flexible Arm of the Octopus: Physiological Characterization J Neurophysiol, March 1, 2000; 83(3): 1315 - 1328. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. E. Fox and P. E. Lloyd Role of cAMP in the Short-Term Modulation of a Neuromuscular System in Aplysia J Neurophysiol, March 1, 2000; 83(3): 1567 - 1579. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Keating and P. E. Lloyd Differential Modulation of Motor Neurons That Innervate the Same Muscle but Use Different Excitatory Transmitters in Aplysia J Neurophysiol, October 1, 1999; 82(4): 1759 - 1767. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |