Figure 1.

Representative recording of the effect of 4-bromopropofol (50 nM) on spontaneous action potential firing of ventral horn neurons. (A) Chemical structures of 4-bromopropofol and propofol differ with respect to the presence of a bromide atom in para-position to the hydroxyl group. (B) Action potentials, visible as the vertical deflections in the voltage traces, were monitored with an extracellular electrode. Under drug-free conditions the neuron generated action potentials at a frequency of 1.6 Hz. Application of 4-bromopropofol reduced the discharge frequency to 1.1 Hz.