ABSTRACT
Tetanus toxin is produced by Clostridium tetani and its clinical effects are due to inhibition of neurotransmitter release at both central inhibitory synapses and at the neuromuscular junction. The toxin is a protein, consisting of a heavy and a light chain linked by disulphide bonds, and is a member of the family of clostridial neurotoxins, including the botulinum toxins, which share structural and functional similarities. Synaptosomes isolated from rat cerebral cortex on Percoll density gradients were washed twice in Krebs’ buffer containing 0.1 mM calcium. Tetanus toxin was a gift from Professor Habermann of Giessen University and was freshly dialyzed and then diluted prior to use with phosphate-buffered-saline containing 0.1% BSA. To ensure that these effects of tetanus toxin were compatible with its normal biological action of inhibiting release and were not due to some non-specific toxicity two experiments were undertaken.
