Engelmann, Jacob; Bacelo, Joao; van den Burg, Erwin; Grant, Kirsty
Abstract / Bemerkung
The effects of anesthesia with etomidate on the cellular mechanisms of sensory processing and sensorimotor coordination have been studied in the active electric sense of the mormyrid fish Gnathonemus petersii. Like many anesthetics, etomidate is known to potentiate GABA(A) receptors, but little is known about the effects on sensory processing at the systems level. A better understanding is necessary for experimental studies of sensory processing, in particular regarding possible effects on the dynamic structure of excitatory and inhibitory receptive fields and to improve the knowledge of the mechanisms of anesthesia in general. Etomidate slowed the electromotor discharge rhythm, probably because of feedback inhibition at the premotor level, but did not alter the structure of the electromotor command. Sensory translation through primary afferents projecting to the cerebellum-like electrosensory lobe (ELL) was not changed. However, central interneurons and projection neurons were hyperpolarized under etomidate, and their spiking activity was reduced. Although the spatial extent and the center/surround organization of sensory receptive fields were not changed, initial excitatory responses were followed by prolonged inhibition. Corollary discharge input to ELL was maintained, and the temporal sequence of excitatory and inhibitory components of this descending signal remained intact. Later inhibitory corollary discharge responses were prolonged by several hundred milliseconds. The result was that excitatory reafferent sensory input was conserved with enhanced precision of timing, whereas background activity was greatly reduced. Anti-Hebbian synaptic plasticity evoked by association of sensory and corollary discharge input was still present under anesthesia, and differences compared with the nonanesthetized condition are discussed.
Somatosensory/physiology; Evoked Potentials; Evoked Potentials; Motor/physiology; Action Potentials/physiology; Action Potentials/drug effects; Anesthetics; Intravenous/administration & dosage; Animals; Brain/drug effects; Brain/physiology; Cerebellum/drug effects; Cerebellum/physiology; Cochlear Nucleus/drug effects; Cochlear Nucleus/physiology; Electric Fish/physiology; Electric Organ/drug effects; Etomidate/pharmacology; Electric Organ/physiology; Neurons/drug effects; Neurons/physiology; Sense Organs/drug effects; Sense Organs/physiology
Journal of neurophysiology
Engelmann J, Bacelo J, van den Burg E, Grant K. Sensory and motor effects of etomidate anesthesia. Journal of neurophysiology. 2006;95(2):1231-1243.
Engelmann, J., Bacelo, J., van den Burg, E., & Grant, K. (2006). Sensory and motor effects of etomidate anesthesia. Journal of neurophysiology, 95(2), 1231-1243. doi:10.1152/jn.00405.2005
Engelmann, J., Bacelo, J., van den Burg, E., and Grant, K. (2006). Sensory and motor effects of etomidate anesthesia. Journal of neurophysiology 95, 1231-1243.
Engelmann, J., et al., 2006. Sensory and motor effects of etomidate anesthesia. Journal of neurophysiology, 95(2), p 1231-1243.
J. Engelmann, et al., “Sensory and motor effects of etomidate anesthesia”, Journal of neurophysiology, vol. 95, 2006, pp. 1231-1243.
Engelmann, J., Bacelo, J., van den Burg, E., Grant, K.: Sensory and motor effects of etomidate anesthesia. Journal of neurophysiology. 95, 1231-1243 (2006).
Engelmann, Jacob, Bacelo, Joao, van den Burg, Erwin, and Grant, Kirsty. “Sensory and motor effects of etomidate anesthesia”. Journal of neurophysiology 95.2 (2006): 1231-1243.