Single jaw-muscle spindle afferent axons were characterized physiologically and intracellularly stained to determine whether particular physiological types of spindle afferent show distinctive morphologies. Microelectrodes filled with either horseradish peroxidase (HRP) or biotinamide (Neurobiotin) were advanced into the mesencephalic trigeminal nucleus (Vme) in anesthetized rats. Intracellular...

The aim of this study was to investigate whether primary vestibular afferent fibers establish direct connections with the motor and sensory trigeminal system in the brainstem of the frog. The experiments were carried out on Rana esculenta. In anaesthetized animals the trigeminal and vestibular nerves were prepared, and their proximal stumps were labeled either with fluorescein binding dextran a...

Palisade endings are nerve specializations found in the extraocular muscles (EOMs) of mammals, including primates. They have long been postulated to be proprioceptors. It was recently demonstrated that palisade endings are cholinergic and that in monkeys they originate from the EOM motor nuclei. Nevertheless, there is considerable difference of opinion concerning the nature of palisade ending f...

The trigeminal reflex blink is an ideal system to investigate whether stimulus paradigms that produce long-term potentiation (LTP) in vitro modify motor learning in humans. Presentation of 12 trains of low-intensity, high-frequency stimuli (HFS) to the supraorbital branch of the trigeminal nerve (SO) modified subsequent reflex blinks of human subjects. When HFS occurred concurrently with reflex...

Intracellular recordings were obtained from rat trigeminal motoneurons in slice preparations to investigate the role of calcium conductances in the depolarizing and hyperpolarizing spike afterpotential (ADP and mAHP, respectively). The mAHP was suppressed by bath application of 1 microM apamin, 2 mM Mn2+, and 2 mM Co2+, and also by intracellular injection of ethylene glycol-bis(b-aminoethylenet...

Because of their many inputs and bilateral projections, interneurons surrounding the trigeminal motor nucleus (MotV) are thought to be very important in control of jaw movements and reflexes. However, their interactions with the trigeminal motoneurons are almost unknown. In the present study an in vitro slice preparation was used to investigate this relationship in rat. The zone bordering MotV ...

Cortically evoked rhythmic mastication was variously modified by stimulation of the superior laryngeal nerve and by elicitation of reflex swallowing in rabbits under light ether anesthesia.The recording of the unitary activity was made from motoneurons in the motor nucleus of the trigeminal nerve or from motor fibers in the trigeminal nerve to study the neural mechanism subserving such modifica...

Retrograde transneuronal tracing with rabies virus from the right orbicularis oculi muscle was used to identify neural networks underlying spontaneous, reflex, and learned blinks. The kinetics of viral transfer was studied at sequential 12 hr intervals between 3 and 5 d after inoculation. Rabies virus immunolabeling was combined with the immunohistochemical detection of choline acetyltransferas...

Introduction: Appropriate thyroid hormone (TH) levels are essential during the critical period of brain development, which is associated with the growth of axons and dendrites and synapse formation. In rats, oral motor circuits begin to reach to their adult pattern around 3 weeks after birth, the period in which alteration from sucking to biting and chewing occurs (weaning time). Trigeminal mot...