Voltage-gated sodium channels in cerebellar Purkinje cells of mormyrid fish.

Cerebellar Purkinje cells of mormyrid fish differ in some morphological as well as physiological parameters from their counterparts in mammals. Morphologically, Purkinje cells of mormyrids have larger dendrites that are characterized by a lower degree of branching in the molecular layer. Physiologically, there are differences in electrophysiological response patterns that are related to sodium channel activity: first, sodium spikes in mormyrid Purkinje cells have low amplitudes, typically not exceeding 30 mV.

Otolith deprivation induces optokinetic compensation.

According to the multisensory integration theory vestibular, optokinetic and proprioceptive inputs act in concert to maintain a stable retinal image of the visual world. Yet, it remains elusive to what extent the otolith organs contribute to this process and whether a specific loss of otolith input is compensated for. Here we investigated the compensatory eye movements in tilted mice, which lack otoconia because of a mutation in otopetrin 1.

Hearing loss in infantile Pompe's disease and determination of underlying pathology in the knockout mouse.

Hearing deficit occurs in several lysosomal storage disorders but has so far not been recognized as a symptom of Pompe's disease (glycogen storage disease type II). We discovered quite unexpectedly 30-90 dB hearing loss in four infants with Pompe's disease, who participated in a study on the safety and efficacy of enzyme replacement therapy. Three other patients with juvenile Pompe's disease did not have this symptom.