title: The contribution of inferior colliculus activity to the auditory brainstem response (ABR) in mice.
abstract: In mice, the auditory brainstem response (ABR) is frequently used to assess hearing status in transgenic hearing models. The diagnostic value of the ABR depends on knowledge about the anatomical sources of its characteristic waves. Here, we studied the contribution of the inferior colliculus (IC) to the click-evoked scalp ABR in mice. We demonstrate a non-invasive correlate of the IC response that can be measured in the scalp ABR as a slow positive wave P0with peak latency 7-8 ms when recorded with adequate band-pass filtering. Wave P0showed close correspondence in latency, magnitude and shape with the sustained part of evoked spiking activity and local field potentials (LFP) in the central nucleus of the IC. In addition, the onset peaks of the IC response were related temporally to ABR wave V and to some extent to wave IV. This relation was further supported by depth-dependent modulation of the shape of ABR wave IV and V within the IC suggesting generation within or in close vicinity to the IC. In conclusion, the slow ABR wave P0in the scalp ABR may represent a complementary non-invasive marker for IC activity in the mouse. Further, the latency of synchronized click-evoked activity in the IC supports the view that IC contributes to ABR wave V, and possibly also to ABR wave IV.
authors: Institute of AudioNeuroTechnology (VIANNA) & Department of Experimental Otology, Hannover Medical School, 30625 Hannover, Germany. Electronic address: land.ruediger@mh-hannover.de.
authors: Rüdiger
authors: R
authors: Land
authors: Institute of AudioNeuroTechnology (VIANNA) & Department of Experimental Otology, Hannover Medical School, 30625 Hannover, Germany.
authors: Alice
authors: A
authors: Burghard
authors: Institute of AudioNeuroTechnology (VIANNA) & Department of Experimental Otology, Hannover Medical School, 30625 Hannover, Germany.
authors: Andrej
authors: A
authors: Kral
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D001309:Auditory Threshold / Q000502:physiology*; D001933:Brain Stem / Q000502:physiology; D005072:Evoked Potentials, Auditory; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology*; D005260:Female; D006309:Hearing; D006320:Hearing Tests; D007245:Inferior Colliculi / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D010641:Phenotype; D011930:Reaction Time / Q000502:physiology; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors
keywords: ABR; Auditory brainstem response; IC; Inferior colliculus; MLR; Middle latency response; Phenotyping