Helium pressure alteration of function in squid giant synapse

Area of Science:

• Neuroscience
• High-pressure physiology

Background:

• The squid giant synapse is a model for studying synaptic transmission.
• High pressure nervous syndrome (HPNS) effects are not fully understood.

Purpose of the Study:

• To investigate the effects of high helium pressure on synaptic transmission in the squid giant synapse.
• To determine if pressure interferes with action potential propagation and postsynaptic potentials.

Main Methods:

• Intracellular electrical recordings were made from the squid giant synapse.
• Presynaptic stimulation and postsynaptic recording were performed under helium pressures up to 204 atm.

Main Results:

• Synaptic transmission of action potentials was altered but not prevented by high pressure.
• Pressure prolonged synaptically transmitted action potentials.
• Slowing of the excitatory postsynaptic potential and increased synaptic fatigue were observed at 35 atm.

Conclusions:

• High pressure modifies synaptic transmission efficacy and speed.
• Observed changes in synaptic function may contribute to high-pressure nervous effects.
• Pressure-induced alterations in information transfer are a potential mechanism for HPNS.