Effects on enflurane on gill withdrawal behaviors and the ability of gill motor neurones to elicit gill contractions in aplysia.
We used the Aplysia gill withdrawal reflex model system in order to study how enflurane effected both gill withdrawal adaptive behaviors and the activity of single identified neurones which are involved with the mediation of the gill withdrawal response. We found that a continuous superfusion of enflurane (0.5 and 1.0%) solution over the abdominal ganglion (the CNS) resulted in an increase in the spontaneous gill respiratory movements; an increase in the spontaneous discharges in identified central motor neurones; and a depolarizing shift in the resting membrane potential of these neurones. Enflurane also significantly effected the ability of the gill motor neurones to elicit a gill contraction when the motor neurone was depolarized to produce action potentials by passing depolarizing current into the neurone. Although in most cases the ability of the motor neurone to elicit a gill withdrawal contraction was decreased, that in one third of the cases was increased. Enflurane may exert its actions by effecting the activity of CNS control neurones which exert both facilitatory and suppressive control over the peripheral nervous system in the gill as well as by having direct effects on the motor neurones.
Komatsu
H
H
Department of Anesthesiology & Emergency Medicine, Kagawa Medical School, Kagawa, Japan.
Lukowiak
K
K
Ogil
K
K