JOURNAL ARTICLE

Actions of midazolam on GABAergic transmission in substantia gelatinosa neurons of adult rat spinal cord slices

T Kohno, E Kumamoto, H Baba, T Ataka, M Okamoto, K Shimoji, M Yoshimura
Anesthesiology 2000, 92 (2): 507-15
10691239

BACKGROUND: Although intrathecal administration of midazolam has been found to produce analgesia, how midazolam exerts this effect is not understood fully at the neuronal level in the spinal cord.

METHODS: The effects of midazolam on either electrically evoked or spontaneous inhibitory transmission and on a response to exogenous gamma-aminobutyric acid (GABA), a GABA(A)-receptor agonist, muscimol, or glycine were evaluated in substantia gelatinosa neurons of adult rat spinal cord slices by using the whole-cell patch-clamp technique.

RESULTS: Bath-applied midazolam (1 microM) prolonged the decay phase of evoked and miniature inhibitory postsynaptic currents (IPSCs), mediated by GABA(A) receptors, without a change in amplitudes, while not affecting glycine receptor-mediated miniature inhibitory postsynaptic currents in both the decay phase and the amplitude. Either GABA- or muscimol-induced currents were enhanced in amplitude by midazolam (0.1 microM) in a manner sensitive to a benzodiazepine receptor antagonist, flumazenil (1 microM); glycine currents were, however, unaltered by midazolam.

CONCLUSIONS: Midazolam augmented both the duration of GABA-mediated synaptic current and the amplitude of GABA-induced current by acting on the GABA(A)-benzodiazepine receptor in substantia gelatinosa neurons; this would increase the inhibitory GABAergic transmission. This may be a possible mechanism for antinociception by midazolam.

Full Text Links

Find Full Text Links for this Article

Discussion

You are not logged in. Sign Up or Log In to join the discussion.

Trending Papers

Remove bar
Read by QxMD icon Read
10691239
×

Save your favorite articles in one place with a free QxMD account.

×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"