Anesthesia and analgesia
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Anesthesia and analgesia · Dec 2009
Gamma-aminobutyric acid type A receptor alpha 4 subunit knockout mice are resistant to the amnestic effect of isoflurane.
General anesthesia produces multiple end points including immobility, hypnosis, sedation, and amnesia. Tonic inhibition via gamma-aminobutyric acid type A receptors (GABA(A)-Rs) may play a role in mediating behavioral end points that are suppressed by low concentrations of anesthetics (e.g., hypnosis and amnesia). GABA(A)-Rs containing the alpha4 subunit are highly concentrated in the hippocampus and thalamus, and when combined with delta subunits they mediate tonic inhibition, which is sensitive to low concentrations of isoflurane. ⋯ These results lend support to the hypothesis that different sites of action mediate different anesthetic end points and suggest that alpha4-containing GABA(A)-Rs are important mediators of the amnestic effect of isoflurane on hippocampal-dependent declarative memory.
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Anesthesia and analgesia · Dec 2009
Early changes in Homer1 proteins in the spinal dorsal horn are associated with loose ligation of the rat sciatic nerve.
Plasticity in the spinal dorsal horn is thought to underlie, at least in part, pain behavior after peripheral nerve injury. Homer1 proteins play an important role in synaptic plasticity through an activity-dependent remodeling of the postsynaptic density (PSD). In this study, we examined the early consequences of the loose ligation of the sciatic nerve on the levels of Homer1a and Homer1b/c proteins in the PSD of spinal dorsal horn neurons. ⋯ The ligation-associated changes in the protein levels of Homer1a and Homer1b/c in the ipsilateral PSD of spinal dorsal horn neurons may be an important early reflection of the injury-associated plasticity that in time leads to the development of persistent pain.
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Anesthesia and analgesia · Dec 2009
Ketoprofen produces modality-specific inhibition of pain behaviors in rats after plantar incision.
Postoperative pain remains a significant problem despite optimal treatment with current drugs. Nonsteroidal antiinflammatory drugs reduce inflammation and provide analgesia but are associated with adverse side effects. ⋯ This study demonstrates that ketoprofen is an effective analgesic for nonevoked guarding in rats after plantar incision. There was no effect on mechanical or heat responses, which highlights the importance of multiple-modality testing of pain behaviors for drug evaluation. We found efficacy at doses used clinically in postoperative patients.