Effects of a toxic phospholipase A2 (AgTx) from the venom of the Pit viper (Agkistrodon halys (Pallas)) on the crayfish stretch receptor neuron.

Neurotoxicity of an isolated fraction (V) of the venom from the snake Agkistrodon halys (Pallas) was studied on the crayfish stretch receptor using a two-electrode voltage-clamp technique. The toxin was previously shown to have less phospholipase A2 activity but to be more toxic in mice compared with bee venom phospholipase A2. At 5 micrograms ml-1 (0.

Effects of intracellular TEA injection on early adaptation of crustacean stretch receptor.

The effects of intracellular injection of TEA on the stretch-induced response of the slowly adapting stretch receptor of the crayfish have been examined to determine the contribution of an outward potassium current to the early adaptation of the neuron. Intracellular recording techniques including potential clamp measurements of membrane currents have been used. Injection of small amounts of TEA caused a pronounced depolarization of the neuron.

Ionic dependence of early adaptation in the crustacean stretch receptor.

In the present study we have examined the effects of changes in potassium and calcium concentration on the early adaptation of the slowly adapting stretch receptor of the crayfish using intracellular recordings including the potential clamp technique. This was because previous studies had suggested that the early adaptative decline of the receptor potential may be attributed mainly to ionic mechanisms involved in the transducer process. During prolonged exposure to K-free saline the cell depolarized; the early adaptive fall of the receptor potential was reduced and finally the response became almost rectangular.