Chronic effect of tetanus toxin applied locally to the cerebral cortex of the dog.

Tetanus toxin injected into the cortex produces convulsions, neurological disability, and a strychnine-like discharging focus, appearing after a minimal latency of 2 days and lasting more than a month. Such a focus, apparently caused by a blockade of inhibitory synapses, does not demonstrate any major damage in microscopic studies.