Hair cell tufts and afferent innervation of the bullfrog crista ampullaris
Autor: | Steven F. Myers, Edwin R. Lewis |
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Rok vydání: | 1990 |
Předmět: |
animal structures
Models Neurological Biology Axonal Transport Epithelium chemistry.chemical_compound Bullfrog Hair Cells Auditory medicine Animals Inner ear Evoked Potentials Molecular Biology Neurons Crista ampullaris Afferent Pathways Lucifer yellow Rana catesbeiana Semicircular canal General Neuroscience Anatomy Axons Semicircular Canals Crista medicine.anatomical_structure Acoustic Stimulation nervous system chemistry Microscopy Electron Scanning Axoplasmic transport Neurology (clinical) Hair cell Developmental Biology |
Zdroj: | Brain Research. 534:15-24 |
ISSN: | 0006-8993 |
DOI: | 10.1016/0006-8993(90)90107-m |
Popis: | Within the bullfrog semicircular canal crista, hair cell tuft types were defined and mapped with the aid of scanning electron microscopy. Intracellular recording and Lucifer Yellow labeling techniques were used to study afferent responses and arborization patterns. Dye-filled planar afferent axons had mean distal axonal diameters of 1.6-4.9 microns, highly branched arbors, and contacted 11-24 hair cells. Dye-filled isthmus afferent axons had mean distal axonal diameters of 1.8-7.9 microns, with either small or large field arbors contacting 4-9 or 25-31 hair cells. The estimated mean number of contacts per innervated hair cell was 2.2 for planar and 1.3 for isthmus afferent neurons. Data on evoked afferent responses were available only for isthmus units that were observed to respond to our microrotational stimuli (less than 3 degrees/s peak rotational velocity). Of 21 such afferent neurons, 8 were successfully dye-filled. Within this small sample, high-gain units had large field arbors and lower-gain units had small field arbors. The sensitivity of each afferent neuron was analyzed in terms of noise equivalent input (NEI), the stimulus amplitude for which the afferent response amplitude is just equivalent to the RMS deviation of the instantaneous spike rate. NEI for isthmus units varied from 0.63 to 8.2 degrees/s; the mean was 3.2 degrees/s. |
Databáze: | OpenAIRE |
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