Comparison of clinical findings and subjective symptoms in a case of multiple evanescent white dot syndrome (MEWDS): A case report from a patient's perspective.

A 38-year-old pathologist developed multiple evanescent white dot syndrome (MEWDS). He documented his visual impairment in detail utilizing a light microscope for pathological diagnosis. Notably, the subjective defects illustrated by the patient were in good spatiotemporal agreement with diagnostic outcomes. The present report enhances the understanding of visual impairment associated with MEWDS through a comparative analysis of subjective experiences and objective clinical findings.

Tracing the source of difficult to settle fine particles which cause turbidity in the Hitotsuse Reservoir, Japan.

A unique method to trace the source of "difficult-to-settle fine particles," which are a causative factor of long-term turbidity in reservoirs was developed. This method is characterized by cluster analysis of XRD (X-ray diffraction) data and homology comparison of major component compositions between "difficult-to-settle fine particles" contained in landslide soil samples taken from the upstream of a dam, and suspended "long-term turbid water particles" in the reservoir, which is subject to long-term turbidity. The experiment carried out to validate the proposed method, demonstrated a high possibility of being able to make an almost identical match between "difficult-to-settle fine particles" taken from landslide soils at specific locations and "long-term turbid water particles" taken from a reservoir. This method has the potential to determine substances causing long-term turbidity and the locations of soils from which those substances came. Appropriate countermeasures can then be taken at those specific locations.

Effects of neck muscle activities during rhythmic jaw movements by stimulation of the medial vestibular nucleus in rats.

This study first examines whether there is rhythmic activity of the neck muscles during cortically induced rhythmic jaw movements in rats anesthetized by urethane. Rhythmic jaw movements were induced by repetitive electrical stimulation of the orofacial motor cortex. An electromyogram in the splenius muscles (spEMG) showed rhythmic bursts during the jaw-opening phase, or during the transition from the jaw-opening phase to the jaw-closing phase. In the sternomastoid (stEMG), however, the electromyogram did not show any bursts during rhythmic jaw movements. A further study then examines whether stimulation of the medial vestibular nucleus (MVN) modulates the rhythmic activity of the neck muscles. Stimuli applied in the jaw-closing phase induced a transient burst in the stEMG, and the duration of activity in the spEMG was increased. Stimuli applied in the jaw-opening phase induced a transient burst in the stEMG and an inhibitory period in the spEMG. These results imply that the MVN is involved in the modulation of neck muscle activities during rhythmic jaw movements induced by stimulating the orofacial motor cortex.

Modulation of cortically induced rhythmic jaw movements in rats by stimulation of the vestibular nuclear complex.

We study whether stimulation of the vestibular nuclear (VN) complex can modulate rhythmic jaw movements in rats anesthetized by urethane. Rhythmic jaw movements were induced by repetitive electrical stimulation of the orofacial motor cortex. Stimulation of the medial vestibular nucleus (MVN) during the jaw-closing phase increased the amplitude of the jaw-closing movement. (This is not a movement that continues to closure.) Stimulation of the MVN during the jaw-opening phase disturbed the rhythm of jaw movements and induced a small jaw-closing movement. Stimulation of the superior VN (SVN) and the lateral VN (LVN) during the jaw-closing phase did not affect the amplitude of the jaw-closing movement. Stimulation of the SVN and the LVN during the jaw-opening phase increased the amplitude of the jaw-opening movement, however. Stimulation of the inferior VN during the jaw-closing and the jaw-opening phase, respectively decreased the amplitude of the jaw-closing and the jaw-opening movements. Stimulation applied outside the VN did not modulate the amplitude of the jaw movements. These results imply that the VN is involved in the modulation of rhythmic jaw movements induced by stimulation of the orofacial motor cortex.

Multi-source inputs converge on the superior salivatory nucleus neurons in anaesthetized rats.

Activation of parasympathetic nerves innervating salivary glands evokes not only salivation but also vascular responses. These parasympathetic nerves may have cardiac and/or respiratory-related activity as well as the cardiovascular sympathetic nerves that control vascular bed of salivary glands. Therefore, we investigated whether preganglionic superior salivatory nucleus (SSN) neurons projecting to the submandibular and intra-lingual ganglia exhibit pulse-related and/or respiratory-related activity, and whether they can be excited by electrical stimulation of the lingual nerve. 25% of SSN neurons were found to have pulse-related and tracheal pressure-related activities, implying that they receive cardiac and respiratory inputs. 44% of neurons exhibited only pulse-related activity, whereas 31% of the neurons had neither pulse-related nor tracheal pressure-related activity. Neurons with pulse and tracheal pressure-related activities, and those only with pulse-related activity, had B and C fibre range axons. 53% of SSN neurons received both cardiac and lingual nerve inputs. 16% of neurons recorded were found to receive only cardiac inputs, and 26% only lingual nerve inputs; whereas 5% received neither cardiac nor lingual nerve inputs. We conclude that the inputs from diverse sources converge on the SSN neurons, and they can cooperate to modulate SSN neuronal activity.

Modulation of the masseteric monosynaptic reflex by stimulation of the vestibular nuclear complex in rats.

The effect of stimulation of the vestibular nuclear complex (VN) on the masseteric monosynaptic reflex (MMR) was studied in anesthetized rats. The MMR was evoked by electrical stimulation of the mesencephalic trigeminal nucleus and was recorded, bilaterally, as the electromyographic responses of the masseter muscles. Conditioning electrical stimulation of the medial vestibular nucleus (MVN) facilitated the MMR bilaterally, as did microinjection of monosodium glutamate into the MVN. In contrast, conditioning electrical stimulation of the inferior vestibular nucleus (IVN) inhibited the MMR bilaterally. Microinjection of monosodium glutamate into the IVN also inhibited the MMR bilaterally. Conditioning electrical stimulation of the lateral and superior vestibular nuclei did not modulate the MMR. These results suggest that the MVN and the IVN are involved in modulation of the MMR and plays an important role in controlling jaw movements.

Modulation of the jaw-opening reflex by stimulation of the vestibular nuclear complex in rats.

The effect of stimulation of the vestibular nuclear complex (VN) on the jaw-opening reflex (JOR) was studied in anesthetized rats. The JOR was evoked by electrical stimulation of the inferior alveolar nerve, and was recorded as the electromyographic responses of the anterior belly of the digastric muscle, bilaterally. Conditioning electrical stimulation of the medial (MVN), lateral (LVN) and superior (SVN) vestibular nuclei facilitated the JOR bilaterally. Microinjection of monosodium glutamate into the SVN, LVN and MVN also facilitated the JOR bilaterally. In contrast, conditioning electrical stimulation of the inferior vestibular nucleus (IVN) inhibited the JOR ipsilaterally. Microinjection of monosodium glutamate into the IVN also inhibited the JOR ipsilaterally. These results suggest that the VN is involved in modulation of the JOR and plays an important role in controlling the jaw movements.

Non-NMDA and NMDA receptor agonists induced excitation and their differential effect in activation of superior salivatory nucleus neurons in anaesthetized rats.

We investigated the effects of the ionophoretic application of ionotropic non-NMDA receptor agonist (AMPA) and NMDA receptor agonist (NMDA) on extracellularly recorded and antidromically identified superior salivatory nucleus (SSN) neurons. A great majority (93%) of SSN neurons was induced to fire by ionophoretic application of AMPA, and they were classified into high firing rate (more than 6 spikes/s), and low firing rate (less than 3 spikes/s) neurons. No clear differences were found between high firing rate and low firing rate neurons according their fibre type and histological locations. Of the SSN neurons that excited by AMPA, 22% (4/18) and 50% (5/9) of the neurons also were induced to fire following ionophoretic application of the NMDA receptor agonist NMDA in different concentrations, 20 mM and 100 mM, respectively. In neurons that induced firing by AMPA and by NMDA, AMPA-evoked firings were induced by the lower intensities of applied current and had higher mean firing rates than NMDA-evoked firing. Neurons that were induced firing by AMPA and by NMDA had B fibre and C fibre axons as well as those that induced firing only by AMPA. Neurons that were fired only by AMPA were found in whole SSN area, whereas neurons that were induced firing by AMPA and by NMDA were mainly found in intermediate SSN area. In conclusion, activation of ionotoropic non-NMDA receptor has a greater excitatory effect on the SSN neurons than that of ionotropic of NMDA receptor. Our data support the view that non-NMDA receptor plays a major role, whereas NMDA receptor plays a minor role, in the activation of SSN neurons.

Changes in cortically induced rhythmic jaw movements after lesioning of the red nucleus in rats.

We study whether the red nucleus (RN) lesion can modify rhythmic jaw movements. Rhythmic jaw movements were induced by repetitive electrical stimulation of the two cortical masticatory areas (area A: the orofacial motor cortex; area P: the insular cortex). Lesions made by applied electric current in the RN were found to influence the rhythmic jaw movements induced by stimulation of A-area. The distance between the maximum and minimum jaw-opening positions was less after the lesions were induced. The duration of rhythmic jaw movements was shorter after lesioning. In contrast, lesions of the RN did not influence rhythmic jaw movements induced by stimulation of the P-area. Next, kainic acid (0.2 microl, lesion group) or phosphate-buffered saline (0.2 microl, control group) was injected into the left RN. Three days after injection, rhythmic jaw movements were induced by repetitive electrical stimulation of the A-area. The distance between the maximum and minimum jaw-opening positions in the lesion group was smaller than in the control group. The rhythmic jaw movements of the lesion group had shorter duration than the control group. These results suggest that the RN is involved in the modification of jaw movements induced by stimulation of the A-area.

Effect of orofacial motor cortex stimulation on neuronal activity in the red nucleus.

We studied modulation of the activities of the red nucleus (RN) neurons under to electrical stimulation of the orofacial motor cortex (OfM) in urethane-anesthetized rats. Of 57 neurons studied, 30 (53%) neurons modulated the firing patterns. The firing patterns of the RN neurons were classified into four types: an excitation (E) type (n=4), a long inhibition (LI) type (n=4), a short inhibition (SI) type (n=22), and a no-effect type (n=27). These modulated neurons were intermingled in the dorso-ventral part of the RN. Our results suggest that the RN neurons receive excitatory or inhibitory inputs from the OfM.

Rostral parvicellular reticular formation neurons projecting to rostral ventrolateral medulla receive cardiac inputs in anesthetized rats.

The rostral parvicellular reticular formation (rRFp) was explored electrophysiologically in urethane-chloralose anesthetized rats. Spontaneously-active neurons that exhibited a pulse-related activity were recorded and tested for their projections to the rostral ventrolateral medulla (RVLM). About one-third (10/29) of the rRFp neurons that exhibited a pulse-related activity were antidromically activated by RVLM stimulation with conduction velocities between 0.2-4.4m/s and fell within the B and C fibre range. A majority (8/10) of these neurons had a low (<10spikes/s) mean firing rate, whereas a small proportion (2/10) had a high (>15spikes/s) mean firing rate. These findings suggest a direct pathway from the rRFp to the RVLM and suggest that neurons projecting to the RVLM receive cardiac inputs and can modulate RVLM neuronal activity.

Modulation of cortically induced rhythmical jaw movements by stimulation of the red nucleus in the rat.

We study whether stimulation of the red nucleus (RN) can modulate rhythmical jaw movements in rats anesthetized by urethane. Rhythmical jaw movements were induced by repetitive electrical stimulation of the two cortical masticatory areas (area A: the orofacial motor cortex; area P: the insular cortex). Stimuli applied to the RN did influence rhythmical jaw movements induced by stimulation of the A-area. Stimuli applied in the jaw-closing phase increased the amplitude of the jaw-closing movement. Stimuli applied in the jaw-opening phase disturbed the rhythm of jaw movements and induced a small jaw-closing movement. Stimuli applied to the RN did not influence rhythmical jaw movements induced by stimulation of the P-area. These results indicate that the RN is involved in the modulation of rhythmical jaw movements induced by stimulation of the A-area.

Role of the parvicellular reticular formation in facilitating the jaw-opening reflex in rats by stimulation of the red nucleus.

In a previous study, we have shown that electrical and chemical stimulation of the red nucleus (RN) facilitates the jaw-opening reflex (JOR). The RN sends projection fibers bilaterally, with contralateral dominance, to the part of the parvicellular reticular formation (RFp) containing premotor neurons projecting to the trigeminal motor nucleus. This implies that RN-induced facilitation of the JOR might be mediated via last-order neurons in the RFp. Here, we address this issue by investigating whether microinjection of lidocaine or l-glutamate into the RFp affects RN-induced modulation of the JOR. Experiments were performed on rats anesthetized with urethane-chloralose. The JOR was evoked by electrical stimulation of the inferior alveolar (IA) nerve and was recorded as an electromyographic response from the anterior belly of the digastric muscle. Conditioning stimulation was delivered unilaterally to the RN 12 ms before the IA test stimulation. We found that local injections of 2% lidocaine (0.5 microl) into the RFp, contralateral to the RN, significantly (P < 0.05) reduce RN-induced facilitation of the JOR, whereas corresponding injections of 0.1 mM l-glutamate (0.5 microl) significantly (P < 0.05) increase it. These results suggest that the facilitatory effect of RN stimulation on the JOR is mediated partly by a relay in the RFp.

Ionotropic NMDA receptor evokes an excitatory response in superior salivatory nucleus neurons in anaesthetized rats.

Extracellular recordings were taken from preganglionic superior salivatory nucleus (SSN) neurons projecting to submandibular and intra-lingual ganglia, in order to study the action of SSN neurons resulting from ionophoretic application of ionotropic NMDA receptor agonist in urethane-chloralose anaesthetized rats. Single SSN neurons were identified by their antidromic spike responses following stimulation of the chorda-lingual nerve (CLN), chorda tympani branches (CTBs) and the lingual nerve (LN). About one-third (33%, 10/30) of the identified SSN neurons were induced to fire by ionophoretic application of the NMDA receptor agonists used, dl-homocysteic acid (DLH) and N-methyl-D-aspartic acid (NMDA). More than half exhibited firing at high frequencies, often exceeding 40 Hz. About one-fifth (20%; 6/30) of the identified SSN neurons exhibited orthodromic spike responses to the combination of NMDA receptor agonist application and sensory nerve (CLN or LN) stimulus. These excitatory responses evoked by application of NMDA receptor agonist were attenuated (n = 4) by ionophoretic application of DL-2-amino-5-phosphonovaleric acid (AP5; NMDA receptor antagonist). About half (47%) of the neurons did not respond to any combination of NMDA receptor agonist and sensory nerve stimuli. No differences were observed between SSN neurons with B fibre axons and those with C fibre axons in response to ionophoresis of the NMDA receptor agonists. The NMDA-sensitive neurons, which exhibited high frequency firing, were predominantly found in the rostral part of the SSN. In summary, activation of ionotropic NMDA receptors exerts an excitatory effect on about half of the SSN neurons. These data support the view that NMDA receptors are involved in information processing and transmission on SSN neurons.

Facilitation of the jaw reflexes by stimulation of the red nucleus in the rat.

The effects of the red nucleus (RN) stimulation on the jaw-opening reflex (JOR) and the masseteric monosynaptic reflex (MMR) were studied in anesthetized rats. The JOR was evoked by electrical stimulation of the inferior alveolar nerve. The MMR was evoked by electrical stimulation of the mesencephalic trigeminal nucleus. The JOR and the MMR were recorded as electromyographic responses of the anterior belly of the digastric and the masseter muscles, respectively. The conditioning electrical stimulation of the RN facilitated both the JOR and the MMR bilaterally. The facilitatory effect on the JOR was much larger than that on the MMR. Additionally, microinjection of monosodium glutamate into the RN also elicited facilitation of the JOR and the MMR. The results suggest the RN plays an important role in reflex control of jaw movements.