Quantitative analysis of neuronal response properties in primary and higher-order auditory cortical fields of awake house mice (Mus musculus).
Bottom Line: Field similarities were noted as significant correlations between CFs and BFs, V-shaped frequency tuning curves, similar minimum response thresholds and non-monotonic rate-level functions in approximately two-thirds of the neurons.Comparative and quantitative analyses showed that the measured response characteristics were, to various degrees, susceptible to influences of anesthetics.Therefore, studies of neuronal responses in the awake AC are important in order to establish adequate relationships between neuronal data and auditory perception and acoustic response behavior.
Affiliation: Institute of Neurobiology, University of Ulm, Institute of Neurobiology 89081 Ulm, Germany; Systems Neurophysiology, Department of Cognitive Neurology, Werner Reichardt Centre for Integrative Neuroscience, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.Show MeSH
Mentions: In the lateral part of the parietal bone contralateral to the recording site, a steel needle (diameter, 0.25 mm; Fine Science Tools, Heidelberg, Germany) was inserted through the skull to contact the brain surface. It served as reference electrode for the electrophysiological recordings. To access the left-side AC, the skull was opened (approximately 5 × 3 mm; Fig.1A and B) to expose the AC between the sutura lambdoidea (caudal), linea temporalis (dorsal), 1–2 mm anterior of the sutura squamosa (rostral), and the ventral sutura squamosa. The dura was left intact, and penetrated by the electrode at every recording site. Then, a custom-made PVC chamber (inner diameter, 6 mm) was glued with ultraviolet-hardening dental cement to the skull surrounding the hole. An antibiotic (Nebacetin; Altana Pharma & Astellas Pharma, Wesel/Munich, Germany) and NaCl (0.9%; B. Braun Melsungen AG, Germany) were applied to the dura mater before the chamber was sealed with a screw cap. Animals recovered from surgery within a few hours and showed normal behavior, i.e. self-grooming, drinking, feeding, and being interested in their environment (walking and sniffing around).
Affiliation: Institute of Neurobiology, University of Ulm, Institute of Neurobiology 89081 Ulm, Germany; Systems Neurophysiology, Department of Cognitive Neurology, Werner Reichardt Centre for Integrative Neuroscience, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.