Effect of spider venom on cochlear nerve activity consistent with glutamatergic transmission at hair cell-afferent dendrite synapse.
Venom from the spider Argiope trifasciata, a highly specific blocker of the ionic channels associated with invertebrate glutamatergic receptors, was perfused through scala tympani of the basal turn of the pig cochlea. Its effect on spontaneous and driven activity of single afferent neurons was studied. 0.1 U/ml spider venom altered the maximum driven activity without an effect on spontaneous activity. 1 U/ml spider venom suppressed both spontaneous and driven activity. These findings are consistent with the hypothesis that L-glutamate is the neurotransmitter of the synapse between inner hair cells and primary auditory afferent neurons. The results also suggest that the differences in spontaneous activity between neurons may originate in variations in neurotransmitter release.
Cousillas
H
H
Department of Physiology, University of Western Australia, Nedlands.
Cole
K S
KS
Johnstone
B M
BM
D000818:Animals; D001180:Arthropod Venoms / Q000494:pharmacology*; D001306:Auditory Pathways / Q000187:drug effects; D003056:Cochlear Nerve / Q000187:drug effects* / Q000502:physiology; D003712:Dendrites / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005072:Evoked Potentials, Auditory / Q000187:drug effects; D005971:Glutamates / Q000502:physiology*; D018698:Glutamic Acid; D006168:Guinea Pigs; D006198:Hair Cells, Auditory / Q000187:drug effects*; D006199:Hair Cells, Auditory, Inner / Q000187:drug effects*; D017470:Receptors, Glutamate; D017981:Receptors, Neurotransmitter / Q000187:drug effects* / Q000502:physiology; D013111:Spider Venoms / Q000494:pharmacology*; D013569:Synapses / Q000187:drug effects*; D009435:Synaptic Transmission / Q000187:drug effects*
D001180:Arthropod Venoms; D005971:Glutamates; D017470:Receptors, Glutamate; D017981:Receptors, Neurotransmitter; D013111:Spider Venoms; D018698:Glutamic Acid