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Kiyoharu Inoue

Publications and source records attributed to Kiyoharu Inoue.

At least 19 recordsLinked to original sources
PubMed2006

Postnatal development of GABAergic axon terminals in the rat nucleus of tractus solitarius.

The proper function of the brain depends on a precise arrangement of excitatory and inhibitory synapses. Although the caudal nucleus of tractus solitarius (cNTS) plays a pivotal role in cardiorespiratory reflexes, we know little about the formation of the local neural network in the cNTS. In the present study, we have focused on GABAergic axon terminals and investigated postnatal changes in GABAergic synaptic organizations in the rat cNTS immunocytochemically at both light and electron microscopic levels. Counting synaptic and non-synaptic GABAergic axon terminals revealed that GABAergic axon terminal number in the cNTS seemed constant until the second postnatal week and that GABAergic axon terminals were reorganized around postnatal day 10 (P10). Electron microscopic observation revealed that more than 20% GABAergic axon terminals formed axosomatic synapses at P2 to P4, but the number of GABAergic axosomatic synapse on neurons with smaller soma (smaller neurons) decreased considerably after P8. Orphan GABAergic boutons were present around somata of smaller neurons at P10, and axodendritic synapse number on thicker dendrites decreased gradually during postnatal development. These results show that GABAergic axon terminals detach from somata of smaller neurons at the second postnatal week. Such morphologic changes in axon terminals could cause changes in electrophysiological activity and might contribute to reorganization of the local network within the cNTS from neonatal to adult type. These postnatal changes in the cNTS local network might be prerequisite for the cardiorespiratory reflexes of the adult type.

Age Factors↗
PubMed2006

Pattern differentiation of excitatory and inhibitory synaptic inputs on distinct neuronal types in the rat caudal nucleus of the tractus solitarius.

Region- and size-specific neuronal organizations of the caudal nucleus of the tractus solitarius (cNTS) were investigated, followed by analyses of excitatory and inhibitory synaptic input patterns onto specific cell types by patch clamp recordings and immunoelectron microscopy. Cell size distribution and numerical density of cNTS neurons were examined in subregions at levels of the area postrema. In the subpostremal and dorsomedial subnuclei, characterized by the presence of dense glutamatergic and sparse GABAergic somata, small calbindin neurons constituted 42% of the total cells. The medial subnucleus contained large numbers of glutamatergic, GABAergic, and catecholaminergic somata and large tyrosine hydroxylase-containing cells constituted 13% in this region. In total, small neurons (<150 microm2) represented about 80% of the cell population in the cNTS. Predominant excitatory postsynaptic currents were observed in the adult small neurons, while inhibitory postsynaptic currents were more evident in larger neurons, irrespective of subnuclear location. This distinct differentiation of postsynaptic current patterns was not evident in neonates. GABAergic synapses were more frequently associated with dendrites of large catecholaminergic cells (73%) than with those of small calbindin-containing cells (10%) in adults. These results indicate that differential synaptic input patterns were developmentally established in distinct small and large neurons.

Animals↗
PubMed2006

Local axonal arborization patterns of distinct neuronal types in the caudal nucleus of the tractus solitarius.

Neurons in the caudal nucleus of the tractus solitarius (cNTS) are quite heterogeneous in cell size (50 to 450 microm(2) in somal area) and other morphologic characteristics. For a more objective classification of cNTS neurons, their morphologic features were analyzed quantitatively based on reconstructed biocytin-filled cells after whole-cell patch-clamp recordings. According to the patterns of axonal branching behaviors, cNTS cells could be classified into two groups: smaller cells (94.1 microm(2) in mean somal area, range 62-120 microm(2), n = 22) and larger cells (245 microm(2) in mean somal area, range 142-411 microm(2), n = 23). Extensive axonal arborization with numerous possible synaptic boutons was specifically associated with smaller neurons, while larger cells possessed no or few axon collaterals, suggesting their distinct roles as local circuit neurons (or interneurons) and projection neurons, respectively. With regard to somatodendritic characteristics, the following correlations with cell size were found: smaller cells had larger form factors than larger cells (P < 0.05). Larger neurons had more extensive dendritic arborization, expressed by total dendritic length (P < 0.01) and number of dendritic branching points (P < 0.01), than smaller cells. It was suggested that small cNTS neurons contribute specifically to an integration of input information generated in the local circuits, while large neurons convey the integrated information to other autonomic brain regions.

Animals↗
PubMed2006

[A case of cervical spondylotic amyotrophy resembling post-polio syndrome].

We reported a 62-year-old man with cervical spondylotic amyotrophy, in whom differentiation from post-polio syndrome was required. At the age of 3, the patient developed acute anterior poliomyelitis that caused muscular atrophy and muscle weakness in the left arm and bilateral lower limbs. At the age of 61, after approximately 58 years of symptomatic stabilization, the patient newly developed muscular atrophy and muscle weakness localized in the triceps muscle of the left arm. Since no sensory disturbance was noted, post-polio syndrome was initially suspected. However, MRI and myelo-CT demonstrated left side compression of the spinal cord at the level of the 6th cervical spine. Therefore, the patient was diagnosed as having cervical spondylotic amyotrophy, and the progression of the disease was prevented by having the patient rest. Since this patient had a history of acute anterior poliomyelitis, the number of anterior horn cells might have been decreased before he developed cervical spondylosis. Therefore, the patient might have shown clinical symptoms of cervical spondylotic amyotrophy mainly consisting of anterior horn disturbance and scarce sensory disturbance.

Cervical Vertebrae↗
PubMed2006

[Skin collagen abnormalities in a Japanese patient with extracranial internal carotid artery dissection followed by extracranial vertebral artery dissection].

A 41-year-old man with hypertension and hyperlipidemia who complained of left hemiparesis after a temporal headache was admitted to our hospital. A cervical MRI with gadolinium enhancement revealed an intramural hematoma is compatible with right extracranial internal carotid artery dissection. Two weeks later, he complained of sudden onset of pain in the right side of his neck. The right extracranial internal carotid artery dissection followed by the right extracranial vertebral artery dissection was diagnosed. Spontaneous cervical artery dissection (SCAD) is one of the causes of stroke in young adults. The pathogenesis of SCAD remains unknown. Minor trauma like an excessive sneeze, migraine, and connective tissue disorders such as fibromuscular dysplasia and Ehlers-Danlos syndrome are well-known as risk factors for SCAD. Pathologically skin collagen abnormalities have been seen in German patients with SCAD without clinical evidence for any specific connective tissue disorder. We examined the ultrastructural morphology of the Japanese patient's dermal connective tissue components by electron microscopy. The patient's collagen fibers contained fibrils with highly variable diameters, and there were other ultrastructural abnormalities, including flower-like fibrils and large-diameter composite fibrils. This is the first report of a case of ultrastructural abnormalities of dermal connective tissue in a Japanese patient with SCAD.

Adult↗
PubMed2006

[Sensory disturbance in the pulp of the fingertips in three patients with cervical myelitis].

We report three patients with cervical myelitis, with sensory disturbance at their fingertips. They exhibited the following clinical features in common: localized sensory disturbance in the pulp of the fingertips, with a positive Lhermitte's sign, but retained deep sensation. T2-weighted MR imaging demonstrated a swelling of the spinal cord at the C2 to C3 level, and a hyperintense lesion in the posterior region of the spinal cord at the same level in all patients. The characteristic symptoms of these three patients might be attributable to the somatotopy in the dorsal column at high cervical levels, because the afferent fibers innervating the fingertips occupy a much wider axial area at the high cervical spinal cord levels than the small surface area actually innervated by them.

Adult↗
PubMed2006

[Neurological findings, neurophysiological examinations, and sural nerve biopsy in a case of Friedreich ataxia].

We report on a 19-year-old Russian man with Friedreich ataxia with an expanded GAA repeat. The symptoms include ataxia of the trunk and lower extremities, dysdiadochokinesia of the upper extremities with left side dominance, square wave jerks, dysarthria, decreased muscle tone, areflexia, hypesthesia, decreased vibration sense and weakness in the lower extremities, extensor plantar response, skeletal abnormalies, and hypertrophic cardiomyopathy. Somatosensory Evoked Potentials elicited by median nerve stimulation suggested involvement of the central pathways, including the posterior column with lateral dominance. Sural nerve biopsy showed a marked decrease in large myelinated fibers (120/mm2) and a moderate decrease in small myelinated fibers (1430/mm2) with normal density of unmyelinated fibers. Carbon dioxide laser stimulation of the upper limbs demonstrated "C-fiber component" toward Adelta fibers and a normal component toward C fibers. Immunohistochemical staining of a skin biopsy from the lateral malleolus for protein gene product 9.5 demonstrated a normal density (18/mm) of intraepidermal nerve fibers. To our knowledge, this is the first report using CO2 laser stimulation, skin biopsy, and sural nerve biopsy that unmyelinated fibers are not involved in Friedreich ataxia.

Adult↗
PubMed2005

Cardiovascular dysautonomia in de novo Parkinson's disease.

BACKGROUND: Clinical symptoms of Parkinson's disease (PD) include not only motor distress, but also autonomic dysfunction. OBJECTIVE: To clarify the progression of autonomic nervous dysfunction in PD. METHODS: The subjects were 44 patients with de novo PD. Autonomic nervous function, including cardiac sympathetic gain, was evaluated on the basis of cardiac radioiodinated metaiodobenzylguanidine (MIBG) uptake, the response to the Valsalva maneuver, and spectral analyses of the RR interval and blood pressure. RESULTS: Decreased cardiac MIBG uptake was found even in patients with early stage PD. MIBG uptake gradually decreased with increased disease severity. Hemodynamic studies using the Valsalva maneuver revealed that patients with early stage PD had reduced baroreceptor reflex sensitivity (BRS) in phase II, but not phase IV. Blood pressures normally rose in phases II and IV, but the increments decreased with disease progression. In early stage PD, the low frequency power of the RR interval (RR-LF) and the ratio (LF/HF) of RR-LF to the high frequency component of the RR interval (RR-HF) were significantly lower than the respective control values, despite no significant difference in RR-HF; these variables decreased with disease progression. CONCLUSION: Our results show that latent sympathetic nervous dysfunction without parasympathetic dysfunction, especially that involving the sinus node, is already present in early stage de novo PD. It is unclear whether the responsible lesion is central or peripheral.

3-Iodobenzylguanidine↗
PubMed2005

Impaired myocardial 123I-metaiodobenzylguanidine uptake in Lewy body disease: comparison between dementia with Lewy bodies and Parkinson's disease.

BACKGROUND: Iodine-123-labeled metaiodobenzylguanidine (123I-MIBG) myocardial scintigraphy has been used to evaluate cardiac sympathetic denervation in Lewy body disease (LBD) including Parkinson's disease (PD) and dementia with Lewy bodies (DLB). Patients with LBD had marked reductions in cardiac MIBG accumulation, indicative of severe impairment of the cardiac sympathetic nervous systems. However, the differences in scintigraphy between DLB and PD have not been determined. OBJECTIVE: To compare cardiac sympathetic function in early disease stage measured with 123I-MIBG scintigraphy between DLB and PD. METHODS: 123I-MIBG myocardial scintigraphy was performed in 22 patients with early-stage DLB, 41 patients with early idiopathic PD and 15 normal control subjects who were matched for age and disease duration. The heart-to-mediastinum (H/M) ratio was calculated. RESULTS: 123I-MIBG uptake of the myocardium was significantly lower in patients with early DLB than in controls. The mean value of H/M ratio in patients with DLB was significantly lower than those in patients with PD, independent of the Hoehn and Yahr stage. CONCLUSIONS: Our findings suggest that cardiac sympathetic function in DLB is severely impaired even in the early disease stage.

3-Iodobenzylguanidine↗
PubMed2005

Preserved myocardial [123I]metaiodobenzylguanidine uptake in autosomal recessive juvenile parkinsonism: first case report.

A decrease in myocardial uptake of iodine-123-labeled metaiodobenzylguanidine (123I-MIBG) has been reported in idiopathic Parkinson's disease (PD) using 123I-MIBG myocardial scintigraphy. However, the patient with autosomal recessive juvenile parkinsonism (AR-JP), caused by the parkin gene, presented here showed normal 123I-MIBG myocardial uptake, suggesting that AR-JP is a distinct disease entity from PD. Although the clinical features of AR-JP are sometimes quite similar to those of late-onset idiopathic PD, 123I-MIBG myocardial scintigraphy may be a powerful tool to differentiate PD from other parkinsonian syndromes, including AR-JP.

3-Iodobenzylguanidine↗
PubMed2005

Nemaline rods in chorea-acanthocytosis.

In chorea-acanthocytosis, a neurological disorder associated with multisystem degeneration, amyotrophy and peripheral neuropathy are sometimes conspicuous. We describe a patient with chorea-acanthocytosis who showed distributed nemaline rods in biopsied muscle. It has been suggested that in chorea-acanthocytosis, the muscle membranous structures are disordered, and our finding may be attributable to this underlying myopathic condition.

Adult↗
PubMed2005

A case of amusia caused by the infarction of anterior portion of bilateral temporal lobes.

It remains an unsettled question which brain regions participate in music perception. During singing a familiar song, the retrieval from long-term memory is necessary, but the mechanism of that retrieval is still unclear. We carried out a detailed examination of musical ability in a patient with amusia and control subjects and identified the lesion sites of our patient using MRI. Compared with controls, the patient manifested the following impairments in music perception: (i) the recognition and discrimination of familiar melodies; (ii) the discrimination of unfamiliar phrases; (iii) the discrimination of isolated chords. During singing familiar nursery songs, the patient showed the replacement of one phrase of the melody. In MRI, the patient had old infarction in the anterior portion of the temporal lobes bilaterally. In conclusion, the anterior temporal lobes participate in the perception and expression of music. During singing, the song is retrieved from long-term memory by a unit of one phrase. The dysfunction of that retrieval caused the replacement of the succeeding phrases of the original with the wrong tune, and we named this phenomenon paramelodia.

Aged↗
PubMed2005

Functional relationship between human rolandic oscillations and motor cortical excitability: an MEG study.

Synchronization and desynchronization of the neural rhythm in the brain play an important role in the orchestration of perception, motor action and conscious experience. Based on the results of electrocorticographic and magnetoencephalographic (MEG) recordings, it has been considered that human rolandic oscillations originate in the anterior bank of the central sulcus (20-Hz rhythm) and the postcentral cortex (10-Hz rhythm): the 20-Hz oscillation is closely related to motor function, while the 10-Hz rhythm is attributed mainly to sensory function. To test whether the rolandic oscillations are functionally relevant to the motor cortical excitability, we examined effects of 1-Hz repetitive transcranial magnetic stimulation (rTMS) of the left primary motor cortex (M1) on movement-related changes of the rolandic oscillations in 12 normal subjects. MEG data recorded during brisk extension of the right index finger in two different sessions (with and without rTMS conditioning) were compared. Motor-evoked potential (MEP) of the right hand muscle was also measured before and after rTMS to assess the motor cortical excitability. We found that 1-Hz rTMS over M1 significantly reduced the movement-related rebound of the 20-Hz oscillation in association with decreased motor cortical excitability. In particular, movement-related rebound of the 20-Hz rhythm was closely tied with motor cortical excitability. These findings further strengthen the notion of functional relevance of 20-Hz cortical oscillation to motor cortical excitability. In the framework of previous studies, the decrease in movement-related rebound may be regarded as a compensatory reaction to the inhibited cortical activity.

Adult↗
PubMed2005

[Dissociated micturitional disturbance in a patient with cervical spondylotic myelopathy].

A 58-year-old man developed dysuria and residual sensation one year after the traffic accident. Half a year later, he developed chest pain and underwent coronary arteriography. Numbness in the left arm, burning sensation below the knees and urinary retention emerged immediately after prolonged neck extention during the examination. He required intermittent catheterization of the bladder because of persistent dysuria. Urodynamic study revealed detrusor-sphincter dyssynergia. The micturitional disturbance improved with the application of a soft cervical collar and a bed rest. MRI of the cervical spine showed spinal cord compression at the C5/6 and a small hyperintensity area on T2WI in the spinal cord at the C5 level. The case suggests that micturitional dysfunction can be severe without remarkable sensorimotor disturbances of the lower extremities in cervical spondylotic myelopathy.

Cervical Vertebrae↗
PubMed2005

[A case of postpartum cerebral angiopathy with intracranial hemorrhage and subarachnoid hemorrhage immediately after delivery].

A 32-year-old woman, gravida 0, para 0, was admitted for delivery at 40 weeks of gestation. She had no history of headache, hypertension, and toxemia. She was delivered of a healthy boy. Although she was given no medication during normal delivery, she suddenly became drowsy and developed left hemiparesis immediately after delivery. Computed tomographic (CT) scan of the brain performed on the admission day revealed a subarachnoid hemorrhage and right putaminal hemorrhage. A 4-vessel cerebral angiogram demonstrated multiple irregular narrowing of the anterior cerebral arteries, middle cerebral arteries, and posterior cerebral arteries. Her conditions seemed to improve without any medication, and the multiple stenoses were no longer observed by angiography in a follow-up examination. On the basis of these observations, she was diagnosed as having postpartum cerebral angiopathy (PCA). Pathogenesis of PCA still remaing unclear to date an ergot alkaloid derivate (ergonovine) and the hydrogenated form of the powerful vasoconstrictor ergot (bromocriptine) have been reported as cause of PCA. We will classify PCA into 3 categories: eclampsia, secondary PCA, and primary PCA. "Primary PCA" is of unknown etiology, "secondary PCA" results from a known etiology such as drugs, and "eclampsia" is a PCA with toxemia of pregnancy. We report here, that PCA may occur even in a normal pregnant woman who was given no medication, and should be considered in the diagnosis of postpartum cerebral vascular diseases in women.

Adult↗
PubMed2005

[A case of aphasia with preserved repetition due to anterior choroidal artery territory infarction].

A 55-year-old right-handed male patient with atrial fibrillation was admitted to our hospital because of a sudden disturbance of consciousness and right hemiparesis. Neurological examinations revealed left conjugate deviation of the eyes, aphasia, right hemianopsia without macula sparing using a Goldmann perimeter, right hemianesthesia, and right hemiparesis. Magnetic resonance imaging showed low intensity areas (left posterior limb of internal capsule, left cerebral peduncle of middle brain, a part of left substantia nigra, left amygdala, ventral posterior lateral nucleus and ventral anterior nucleus of left thalamus, left lateral geniculate body, and left occipital lobe) in T1 weighted image, due to the infarct in the left anterior choroidal artery territory. Aphasia in this case was accompanied with non-fluent speech, good repetition, naming deficits, and perseveration. We suggest that aphasia with anterior choroidal artery syndrome cannot be classified using the conventional system, and emphasize the importance of accurate descriptions of the symptoms characteristic of aphasia with anterior choroidal artery.

Aphasia↗