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The mammalian inner ear contains the cochlea and vestibular organs, which are responsible for hearing and balance, respectively. The epithelia of these sensory organs contain hair cells that function as mechanoreceptors to transduce sound and head motion. The molecular mechanisms underlying hair cell development and differentiation are poorly understood.(More)
BETA2/NeuroD1 is a bHLH transcription factor that is expressed during development in the mammalian pancreas and in many locations in the central and peripheral nervous systems. During inner ear ontogenesis, it is present in both sensory ganglion neurons and sensory epithelia. Although studies have shown that BETA2/NeuroD1 is important in the development of(More)
The chinchilla crista ampullaris was studied in 10 samples, each containing 32 consecutive ultrathin sections of the entire neuroepithelium. Dissector methods were used to estimate the incidence of various synaptic features, and results were confirmed in completely reconstructed hair cells. There are large regional variations in cellular and synaptic(More)
The distribution of cholinergic fibers in rat cortex was investigated using choline acetyl-transferase immunohistochemistry. Previous studies have either shown differences in distribution, but have been limited to selected areas, or have shown no discernable differences between different cortical areas. In our study, we examined all areas of rat cortex and(More)
Calyx afferents, a group of morphologically and physiologically distinct afferent fibers innervating the striolar region of vestibular sensory epithelia, are selectively labeled by antibodies to the calcium-binding protein calretinin. In this study, the population of calretinin-stained calyx afferents was used to delineate and quantify the striolar region(More)
Many primary vestibular afferents form large cup-shaped postsynaptic terminals (calyces) that envelope the basolateral surfaces of type I hair cells. The calyceal terminals both respond to glutamate released from ribbon synapses in the type I cells and initiate spikes that propagate to the afferent's central terminals in the brainstem. The combination of(More)
The horizontal angular vestibuloocular reflex (VOR) evoked by high-frequency, high-acceleration rotations was studied in four squirrel monkeys after unilateral plugging of the three semicircular canals. During the period (1-4 days) that animals were kept in darkness after plugging, the gain during steps of acceleration (3, 000 degrees /s(2), peak velocity =(More)
We made flattened neuroepithelial preparations of horizontal and vertical (anterior and posterior) cristae from mouse, rat, gerbil, guinea pig, chinchilla, and tree squirrel. Calretinin immunohistochemistry was used to label the calyx class of afferents. Because these afferents are restricted to the central zone of the crista, their distribution allowed us(More)
We have previously shown that there is a slowly progressing, frequency-specific recovery of the gain and phase of the horizontal vestibuloocular reflex (VOR) in rhesus monkeys following plugging of the lateral semicircular canals. The adapted VOR response exhibited both dynamic and spatial characteristics that were distinctly different from responses in(More)
The type I and type II hair cells of mature amniote vestibular organs have been classified according to their afferent nerve terminals: calyx and bouton, respectively. Mature type I and type II cells also have different complements of voltage-gated channels. Type I cells alone express a delayed rectifier, gK,L, that is activated at resting potential. We(More)