(1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (1S,3R-ACPD) induces burst firing via an inositol-1,4,5-triphosphate-independent pathway at rat dorsolateral septal nucleus.
We have previously reported that a L-2-amino-3-phosphonopropionate (L-AP3)-sensitive metabotropic glutamate receptor was required for the induction of long-term potentiation (LTP) in rat dorsolateral septal nucleus neurons. (1S,3R)-1-Aminocyclopentane-1,3-dicarboxylic acid (1S,3R-ACPD), a selective agonist for metabotropic glutamate receptors, also causes burst firing of dorsolateral septal nucleus (DLSN) neurons. In this study, we investigated whether this response was mediated by a phospholipase C-(PLC) coupled metabotropic glutamate receptor. The threshold concentration of 1S,3R-ACPD for the induction of burst firing was about 5 microM, while 10 microM 1S,3R-ACPD produced a maximal effect. L-AP3 (50 microM) reduced the burst firing induced by 1S,3R-ACPD (5 microM). Although 1S,3R-ACPD stimulated the formation of inositol-1,4,5-triphosphate [Ins(1,4,5)P3] suggesting the presence of PLC-coupled metabotropic glutamate receptors, it was only effective in a higher (30-100 microM) concentration range. In addition, the 1S,3R-ACPD-stimulated formation of Ins(1,4,5)P3 level was not affected by L-AP3. These observations suggest that the 1S,3R-ACPD induced burst firing is not mediated by PLC-coupled metabotropic glutamate receptors.
Zheng
F
F
Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston 77555-1031.
Lonart
G
G
Johnson
K M
KM
Gallagher
J P
JP
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D003515:Cycloleucine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004594:Electrophysiology; D066298:In Vitro Techniques; D015544:Inositol 1,4,5-Trisphosphate / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D009498:Neurotoxins / Q000494:pharmacology*; D016548:Prosencephalon / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018094:Receptors, Metabotropic Glutamate / Q000187:drug effects; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors / Q000378:metabolism
D009498:Neurotoxins; D018094:Receptors, Metabotropic Glutamate; D003515:Cycloleucine; C036361:1-amino-1,3-dicarboxycyclopentane; D015544:Inositol 1,4,5-Trisphosphate; D010738:Type C Phospholipases