title: Further structure activity studies on the excitatory amino acid receptors of the crustacean neuromuscular junction.
abstract: Intracellular recordings of the membrane potential and evoked excitatory junction potentials were made from the opener muscle in the walking leg of the Hermit crab ( Eupagurus bernhardus ). A variety of amino acid analogues including cis and trans 1-amino-1,3- dicarboxycyclopentane were tested for agonist activity and their potencies were compared with L-glutamate. Quisqualic acid was the most powerful excitant whereas N-methyl-DL-aspartic acid and ibotenic acid were the least active. Threshold concentrations of L-glutamate and quisqualic acid potentiated the ionophoretic L-glutamate potential and the excitatory junction potentials without affecting membrane input resistance. The results are discussed in terms of the structure-activity relationship of the crustacean excitatory receptor compared to other vertebrate and invertebrate nervous systems.
mesh_terms: D000818:Animals; D033381:Anomura / Q000378:metabolism*; D005071:Evoked Potentials / Q000187:drug effects; D005971:Glutamates / Q000494:pharmacology*; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D009469:Neuromuscular Junction / Q000187:drug effects* / Q000378:metabolism; D017459:Receptors, Amino Acid; D011956:Receptors, Cell Surface / Q000187:drug effects*; D013329:Structure-Activity Relationship
chemical_list: D005971:Glutamates; D017459:Receptors, Amino Acid; D011956:Receptors, Cell Surface