Chlormethiazole acts on chloride channels in cultured spinal cord neurons

Cellular effects of chlormethiazole (CMZ), a sedative-hypnotic substance, were studied using intracellular recording techniques. As a model system primary cultures of mouse spinal cord neurons were used. CMZ (200 microM) increased the rheobase and decreased the cell input resistance. In addition, the spike after depolarization was decreased. The reversal potential for the CMZ-induced effect was dependent on the chloride ion gradient. It is concluded that CMZ opens calcium dependent chloride ion channels in cultured spinal cord neurons which will result in enhancement of inhibitory neurotransmission.