We quantified 12 neuronal properties of tone processing in order to estimate similarities and differences of function between the fields, and to discuss how far auditory cortex (AC) function in the mouse is comparable to that in awake

monkeys and cats. Extracellular recordings were made from 1400 small clusters of neurons from cortical layers III/IV in the primary fields AI (primary auditory field) and AAF (anterior auditory field), and the higher-order fields AII (second auditory field) and DP (dorsoposterior field). Field specificity was shown with regard to spontaneous activity, correlation between spontaneous and evoked activity, tone response latency, BIBW2992 purchase sharpness of frequency tuning, temporal response Crizotinib supplier patterns (occurrence of phasic responses, phasic-tonic responses, tonic responses, and off-responses), and degree of variation between the

characteristic frequency (CF) and the best frequency (BF) (CF–BF relationship). 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. “
“Secretogranin II (SgII), or chromogranin C, is thought to participate in the sorting and packaging of peptide hormones and neuropeptides into secretory granules and large dense-core vesicle (LDCVs), and also functions as a precursor of neuropeptide secretoneurin. Although SgII is widely distributed in the brain and is predominantly

localized at terminals of mossy fibers in the hippocampus and cerebellum and climbing fibers in the cerebellum, its cellular expression and ultrastructural localization remain Oxaprozin largely unknown. In the present study, we addressed this issue in the adult mouse brain by multiple-labeling fluorescence in situ hybridization and immunofluorescence and by preembedding and postembedding immunoelectron microscopies. SgII was expressed in various neurons, distributed as either tiny puncta or coarse aggregates in the neuropil, and intensely accumulated in perikarya of particular neurons, such as parvalbumin-positive interneurons and mossy cells in the hippocampus and Purkinje cells in the cerebellum. Coarse aggregates were typical of terminals of mossy fibers and climbing fibers. In these terminals, numerous immunogold particles were clustered on individual LDCVs, and one or two particles also fell within small synaptic vesicle-accumulating portions.