Journal of Neuroscience, Vol 3, 2310-2323, Copyright © 1983 by Society for Neuroscience
Tetanus toxin: convulsant action on mouse spinal cord neurons in culture
GK Bergey, RL MacDonald, WH Habig, MC Hardegree and PG Nelson
The effects of direct application of tetanus toxin on fetal mouse spinal
cord neurons in culture are described. Tetanus toxin produces increased
excitation characterized by paroxysmal depolarizing events (PDE). In
contrast to the abrupt onset of convulsant action produced by postsynaptic
glycine antagonist strychnine, the convulsant action of tetanus occurs
after a dose-dependent latent period. The onset of the convulsant action of
tetanus toxin is paralleled by a reduction in observed spontaneous
inhibitory synaptic potentials. Excitatory synaptic events can be
identified as components of some tetanus-PDE. The toxin does not alter
postsynaptic responses to the inhibitory amino acids glycine and
gamma-aminobutyric acid. The latency and convulsant action of tetanus toxin
are consistent with an irreversible presynaptic membrane interaction that
reduces inhibitory transmission, a mechanism of action distinct from those
of convulsants that antagonize inhibitory transmitters at the postsynaptic
membrane.