Pentobarbital modulates transmitter effects on mouse spinal neurones grown in tissue culture

Abstract

GENERAL anaesthetics depress postsynaptic excitatory transmission in the vertebrate central and peripheral nervous systems^1–4 although preserving or prolonging both presynaptic^5–6 and postsynaptic inhibition^7–10. The mechanisms underlying these cellular events and their precise relationship with the phenomenon of general anaesthesia in mammals have not been elucidated. We have used various invertebrate preparations to show that pentobarbital and other general anaesthetics operate at a postsynaptic level to depress Na⁺-dependent postsynaptic excitation without affecting either Cl⁻- or K⁺-dependent postsynaptic inhibition^11,12. Here, using intracellular recording from mouse spinal neurones grown in tissue culture, we show that pentobarbital depresses glutamate excitation and prolongs γ-aminobutyric acid (GABA) inhibition in most cells, through a postsynaptic mechanism.