title: Pentobarbital anesthesia alters neural responses in the precedence effect.
abstract: The precedence effect (PE) is thought to be beneficial for proper localization and perception of sounds. The majority of recent physiological studies focus on the neural discharges correlated with PE in the inferior colliculus (IC). Pentobarbital anesthesia is widely used in physiological studies. However, little is known of the effect of pentobarbital on the discharge of neurons in PE. Neuronal responses in the IC from 23 male SD rats were recorded by standard extracellular recording techniques following presentation of 4 ms white noise bursts, presented from either or both of two loud speakers, at different interstimulus delays (ISDs). The neural responses were recorded for off-line analysis before or after intraperitoneal administration of pentobarbital at a loading or maintenance dose. Data were assessed by one-way repeated measures analysis of variance and pairwise comparisons. When the ipsilateral stimuli were leading, pentobarbital at a loading dose significantly increased normalized response to lagging stimuli during recovery from anesthesia. However, it was not the case when the contralateral stimuli were leading. At a maintenance dose, the normalized response to lagging stimuli were significantly reduced, independent of whether contralateral or ipsilateral stimuli were leading. These data show that pentobarbital have no effect on the normalized response of leading stimuli but can prolong the recovery time of lagging stimuli to paired sources produced PE illusions, which was gradually attenuated during recovery from anesthesia. Thus, extracellular recording immediately after administration of pentobarbital should be avoided in physiological studies of neural correlates of PE.
authors.affiliation: Department of Otorhinolaryngology Head and Neck Surgery, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, People's Republic of China.
authors.forename: Penglong
authors.initials: P
authors.lastname: Song
authors.forename: Ningyu
authors.initials: N
authors.lastname: Wang
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Xie
authors.forename: Jun
authors.initials: J
authors.lastname: Jia
authors.forename: Huijun
authors.initials: H
authors.lastname: Li
mesh_terms: D000161:Acoustic Stimulation; D000759:Adjuvants, Anesthesia / Q000009:adverse effects*; D000818:Animals; D007245:Inferior Colliculi / Q000187:drug effects*; D008297:Male; D009474:Neurons / Q000187:drug effects*; D010424:Pentobarbital / Q000009:adverse effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013017:Sound Localization / Q000187:drug effects*
chemical_list: D000759:Adjuvants, Anesthesia; D010424:Pentobarbital