Reduced Sensitivity to Anesthetic Agents upon Lesioning the Mesopontine Tegmental Anesthesia Area in Rats Depends on Anesthetic Type

Conclusions Inability to induce anesthesia in lesioned animals using normally effective doses of etomidate, propofol, and pentobarbital suggests that the mesopontine tegmental anesthesia area is the effective target of these, but not necessarily all, GABAergic anesthetics upon systemic administration. Cortical and spinal functions are likely suppressed by recruitment of dedicated ascending and descending pathways rather than by direct, distributed drug action.Editor ’s PerspectiveWhat We Already Know about This TopicLesions of the mesopontine tegmental anesthesia area in the brainstem render rats strongly insensitive to pentobarbitalThe effects of mesopontine tegmental anesthesia area lesions on responses to other anesthetics have not been previously reportedWhat This Article Tells Us That Is NewTargeted microinjection of ibotenic acid into the mesopontine tegmental anesthesia area in adult rats led to an up to twofold loss in anesthetic potency of etomidate and propofolIn contrast, the potency of ketamine, medetomidine, and alfaxolone/alfadolone was unaffectedThese observations suggest that the mesopontine tegmental anesthesia area of the brainstem may serve as a key structure to selectively mediate transition from wakefulness into an anesthetic state in response to γ-aminobutyric acid–mediated anesthetics

Source: Anesthesiology - February 12, 2020 Category: Anesthesiology Source Type: research