title: Effects of ketamine on response properties of neurons in the superior paraolivary nucleus of the mouse.
abstract: The superior paraolivary nucleus (SPON; alternative abbreviation: SPN for the same nucleus in certain species) is a prominent brainstem structure that provides strong inhibitory input to the auditory midbrain. Previous studies established that SPON neurons encode temporal sound features with high precision. These earlier characterizations of SPON responses were recorded under the influence of ketamine, a dissociative anesthetic agent and known antagonist of N-methyl-d-aspartate glutamate (NMDA) receptors. Because NMDA alters neural responses from the auditory brainstem, single unit extracellular recordings of SPON neurons were performed in the presence and absence of ketamine. In doing so, this study represents the first in vivo examination of the SPON of the mouse. Herein, independent data sets of SPON neurons are characterized that did or did not receive ketamine, as well as neurons that were recorded both prior to and following ketamine administration. In all conditions, SPON neurons exhibited contralaterally driven spikes triggered by the offset of pure tone stimuli. Ketamine lowered both evoked and spontaneous spiking, decreased the sharpness of frequency tuning, and increased auditory thresholds and first-spike latencies. In addition, ketamine limited the range of modulation frequencies to which neurons phase-locked to sinusoidally amplitude-modulated tones.
authors: Department of Otolaryngology-Head and Neck Surgery, and the Sensory Neuroscience Research Center, PO Box 9303 Health Sciences Center, West Virginia University School of Medicine, Morgantown, WV 26506, USA.
authors: R A
authors: RA
authors: Felix
authors: A
authors: A
authors: Kadner
authors: A S
authors: AS
authors: Berrebi
mesh_terms: D000075:Acepromazine / Q000494:pharmacology; D000161:Acoustic Stimulation; D000200:Action Potentials / Q000187:drug effects; D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D001307:Auditory Perception / Q000187:drug effects; D001309:Auditory Threshold / Q000187:drug effects; D001931:Brain Mapping; D018492:Dopamine Antagonists / Q000494:pharmacology; D016057:Evoked Potentials, Auditory, Brain Stem / Q000187:drug effects*; D005260:Female; D007839:Functional Laterality / Q000187:drug effects; D007649:Ketamine / Q000494:pharmacology*; D051379:Mice; D008808:Mice, Inbred CBA; D009847:Olivary Nucleus / Q000166:cytology*; D011930:Reaction Time / Q000187:drug effects; D011984:Sensory Receptor Cells / Q000187:drug effects*; D013016:Sound
chemical_list: D000700:Analgesics; D018492:Dopamine Antagonists; D000075:Acepromazine; D007649:Ketamine