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Kawagishi K, Ando M, Yokouchi K, Sumitomo N, Karasawa M, Fukushima N, Moriizumi T. Stereological quantification of olfactory receptor neurons in mice. Neuroscience 2014; 272:29-33. [PMID: 24797329 DOI: 10.1016/j.neuroscience.2014.04.050] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 04/21/2014] [Accepted: 04/21/2014] [Indexed: 11/27/2022]
Abstract
The total number of olfactory receptor neurons (ORNs) in the mouse main olfactory epithelium (MOE) was estimated using stereological sampling. Noses and skulls of male and female 8-week-old C57BL/6J mice were de-calcified, embedded in paraffin, cut into 10-μm-thick sections serially at 100-μm intervals, and processed for immunohistochemistry for the olfactory marker protein (OMP), a specific marker for ORNs. The number of OMP (+) receptor neurons was measured using an optical fractionator with the Stereo-Investigator software. The mean values of the total number of OMP (+) receptor neurons in the unilateral MOE were 5,140,000±380,000 in males and 5,210,000±380,000 in females, with no significant differences between the sexes. We concluded that the total number of ORNs in the unilateral MOE is approximately 5×10(6) in mice.
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Affiliation(s)
- K Kawagishi
- Department of Anatomy, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan.
| | - M Ando
- Department of Anatomy, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan
| | - K Yokouchi
- Department of Anatomy, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan
| | - N Sumitomo
- Department of Anatomy, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan
| | - M Karasawa
- Department of Anatomy, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan
| | - N Fukushima
- Department of Anatomy, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan
| | - T Moriizumi
- Department of Anatomy, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan
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Hirayama S, Kawagishi K, Yokouchi K, Fukushima N, Karasawa M, Moriizumi T. Regenerative Capacity of Bulbar Projection Neurons During Development: A Quantitative Neuronal Analysis With Functional Correlation. Chem Senses 2013; 39:47-56. [DOI: 10.1093/chemse/bjt053] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Fukuyama T, Yokouchi K, Fukushima N, Kawagishi K, Kakegawa A, Moriizumi T. Differential effects of hypoglossal and facial nerve injuries on survival and growth of rats at different developmental stages. Int J Dev Neurosci 2006; 24:307-17. [PMID: 16806789 DOI: 10.1016/j.ijdevneu.2006.05.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2006] [Revised: 04/28/2006] [Accepted: 05/05/2006] [Indexed: 10/24/2022] Open
Abstract
The hypoglossal (XII) nerve is made up of functionally different nerve branches: the medial branch related to protrusion of the tongue and the lateral branch related to its retraction. The present study was performed to determine the effects of facial (VII) and XII nerve injuries on the survival and growth of rats in which the unilateral or bilateral VII and XII nerve components (main trunk, XII-trunk; medial branch, XII-med; lateral branch, XII-lat) had been resected at different developmental stages. In the suckling period, unilateral as well as bilateral injuries in the XII-trunk or XII-med nerve produced disturbed milk intake, lower survival rates and growth retardation in the nerve-injured rats. In the transition and mastication periods, only bilateral injury in the XII-trunk or XII-med nerve produced disturbed food intake followed by lower survival rates and growth retardation in those animals. The unilateral XII-lat nerve injury did not have significant effects on milk and food intake, whereas the bilateral injury caused disturbance in milk intake especially at the early neonatal stage. The unilateral VII nerve injury at the early neonatal stage caused deteriorating effects on food intake resulting in lower survival rate and severe growth retardation in the nerve-injured rats. The results indicate that the survival and growth of XII and VII nerve-resected rats differ considerably depending on the nerves injured and the developmental ages of the animals at the time of nerve insult.
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Affiliation(s)
- T Fukuyama
- Department of Pediatrics, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan
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Fujita K, Yokouchi K, Fukuyama T, Fukushima N, Kawagishi K, Moriizumi T. Effects of hypoglossal and facial nerve injuries on milk-suckling. Int J Dev Neurosci 2005; 24:29-34. [PMID: 16384685 DOI: 10.1016/j.ijdevneu.2005.11.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2005] [Revised: 11/08/2005] [Accepted: 11/14/2005] [Indexed: 11/28/2022] Open
Abstract
Functional roles of the perioral anatomical structures involved in breastfeeding were examined in newborn rat pups in which the hypoglossal (XII) and facial (VII) nerves had been resected at the neonatal stage. The XII nerve controls tongue movement and is comprised of two functionally distinct branches: the medial branch related to protrusion of the tongue and the lateral branch related to its retraction. Newborn rat pups with bilateral resection of either of the XII nerve components (main trunk: XII-trunk; medial branch: XII-med; lateral branch: XII-lat) failed to suckle milk and did not survive. Unilateral XII nerve-resected neonates showed different milk-suckling capabilities, which thus resulted in differences in survival rate (XII-trunk: 38%; XII-med: 24%; XII-lat: 92%) and postnatal growth during the postnatal 3 weeks until P21. Unilateral and bilateral resections of the VII nerve innervating the buccolabial musculature produced lowered suckling capabilities and retarded postnatal growth, although all pups showed 100% survival. The results indicate a crucial role of the tongue, especially of protruding muscular elements innervated by the XII-med nerve, in breastfeeding. The results also indicate differential effects of the VII and XII nerve components on suckling capability, survival, and postnatal growth of newborn rat pups.
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Affiliation(s)
- K Fujita
- Department of Anatomy, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan
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Fukushima N, Fujita K, Yokouchi K, Kawagishi K, Moriizumi T. Effects of bilateral resection of facial nerves on suckling in developing rats. Brain Res Bull 2004; 62:385-9. [PMID: 15168903 DOI: 10.1016/j.brainresbull.2003.10.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2003] [Revised: 09/09/2003] [Accepted: 10/23/2003] [Indexed: 10/26/2022]
Abstract
The purpose of the present study is to investigate functional role of the facial nerve on suckling in developing rats. The bilateral resection of facial nerves on postnatal day 1 (P1) resulted in cell loss of facial motoneurons and complete facial paralysis without any whisker movement or nictitating reflex at the end of the postnatal 3 weeks. Although the body weight of the nerve-resected rats increased gradually for the postnatal 3 weeks, they weighed less than the control rats without nerve resection. The nerve-resected rats contained less milk (0.25 +/- 0.02 g) than the control rats (0.35 +/- 0.02 g) in the stomach on P17. On P21, the body weight of the nerve-resected rats (25.33 +/- 0.32 g) was decreased by 28% compared to that of the control rats (35.08 +/- 0.57 g). Although their growth was substantially more retarded than that of the control animals, most (92%) of the nerve-resected pups could survive without facial nerve innervation. The orofacial musculature innervated by the facial nerve plays an important role in breastfeeding, but the present study shows that these muscles are not essential for the survival of neonatal rats.
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Affiliation(s)
- N Fukushima
- Department of Anatomy, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan
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Koyama J, Yokouchi K, Fukushima N, Kawagishi K, Higashiyama F, Moriizumi T. Neurotrophic effect of hepatocyte growth factor on neonatal facial motor neurons. Neurol Res 2003; 25:701-7. [PMID: 14579786 DOI: 10.1179/016164103101202192] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The neurotrophic effect of hepatocyte growth factor (HGF) on axotomized facial motor neurons was examined after local application of HGF to the proximal facial nerve stump of the neonatal rat on post-natal day one (P1). Motor neuron survival was expressed as the neuronal cell count on the injured side as a percentage of that on the noninjured side. Motor neuron survival of the control group was 76% on P3, 54% on P5 and 23% on P8, that of the HGF-treated group 78% on P3, 69% on P5 and 31% on P8, and that of the brain-derived neurotrophic factor (BDNF)-treated group 91% on P5 and 45% on P8. The motor neuron survival rates were then adjusted by deducting the facial motor neurons corresponding to the uninjured retroauricular branch (20%) of the facial nerve. The adjusted values were 70% (P3), 42% (P5) and 4% (P8) for the control group, 72% (P3), 61% (P5) and 14% (P8) for the HGF-treated group, and 88% (P5) and 32% (P8) for the BDNF-treated group. These findings demonstrate that HGF has a neuroprotective effect on injured facial motor neurons and suggest that HGF has neurotrophic properties distinct from those of BDNF.
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Affiliation(s)
- J Koyama
- Department of Neurosurgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan
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Fukushima N, Yokouchi K, Kawagishi K, Ren G, Higashiyama F, Moriizumi T. Proliferating cell populations in experimentally-induced hydrocephalus in developing rats. J Clin Neurosci 2003; 10:334-7. [PMID: 12763340 DOI: 10.1016/s0967-5868(03)00019-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To examine the fate of proliferating brain cells in hydrocephalus (Hydro), experimental Hydro was induced in neonatal rats by intracisternal injection of kaolin and, 3 weeks later, the rats were injected with bromodeoxyuridine (BrdU). The BrdU (+) cells were immunohistochemically analyzed by using antibodies against neural (nestin), neuronal (NeuN) and glial (GFAP and MBP) markers in the posterior cerebrum. The percentage of nestin expression for the BrdU (+) cells was 8% in control and increased from 17% in the Hydro to 33% in the Hydro at an earlier stage after the shunt procedure, but was restored to 6% in the Hydro at a later stage after the shunt procedure. The percentages of GFAP expression showed a similar tendency to those of nestin expression. The BrdU (+) cells did not express either NeuN or MBP throughout the experiments.
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Affiliation(s)
- N Fukushima
- Department of Anatomy, Shinshu University School of Medicine, Matsumoto, 390-8621 Nagano, Japan
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Koyama J, Yokouchi K, Fukushima N, Kawagishi K, Moriizumi T. Great potentiality of neonatal facial motor neurons for neural plasticity as determined by functionally essential neuronal population. Neurosci Res 2003; 46:85-93. [PMID: 12725915 DOI: 10.1016/s0168-0102(03)00033-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The present study was undertaken to determine the neuronal population essential for normal and minimal facial function of young adult rats that had received various degrees of crush injuries to the facial nerve in the neonatal period. Using a neuronal tracer, it was found in young adult rats receiving neonatal injuries that the minimum number of tracer-labeled facial motor neurons necessary for normal facial function corresponded to 13-14% of the neurons (2540+/-64) of the age-matched control animals, whereas the minimum number of neurons necessary for minimal facial function corresponded to 5%. On the other hand, the minimum numbers of tracer-labeled facial motor neurons necessary for normal and minimal facial function of young adult rats that received various degrees of crush injuries corresponded to 61 and 27-30%, respectively, of the neurons (2540+/-64) of the uninjured control animals. These results indicate that the facial function of animals with nerves crushed at the neonatal stage can be adequately maintained by a very small population of neurons, implying a great potential of neonatal neurons for neural plasticity.
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Affiliation(s)
- J Koyama
- Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto 390-8621, Japan
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Fukushima N, Yokouchi K, Kawagishi K, Moriizumi T. Differential neurogenesis and gliogenesis by local and migrating neural stem cells in the olfactory bulb. Neurosci Res 2002; 44:467-73. [PMID: 12445634 DOI: 10.1016/s0168-0102(02)00173-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The rostral migratory stream (RMS) is a unique forebrain structure that provides a long-distance migratory route for the neural stem cells of the periventricular region towards the olfactory bulb (OB). The purpose of the study presented here is to examine the extent of neurogenesis and gliogenesis by the neural stem cells of different origins (periventricular vs. intrabulbar) in the OB. After the RMS had been subjected to injury, the rats received intraperitoneal injections of 5-bromodeoxyuridine (BrdU) and were further reared for 2 weeks. Neuronal and glial differentiations of the BrdU(+) cells in the olfactory bulbar granule cell (OB-GCL) and the olfactory glomerular (OB-GL) layers were examined immunohistochemically using antibodies against neuronal (NeuN, neuronal nuclei) and glial (GFAP, glial fibrillary acidic protein) markers in the OBs with injured and uninjured (control) RMS. In the completely RMS-lesioned OB, where migration of the periventricular neural stem cells was inhibited, a small number of BrdU(+) NeuN(+) cells were found in both the OB-GCL and OB-GL. The BrdU(+) NeuN(+) cells accounted for a much higher percentage of the BrdU(+) cells on the control side (OB-GCL, 36.7%; OB-GL, 8.8%) than on the completely RMS-lesioned side (OB-GCL, 3.7%; OB-GL, 0.6%). The percentage of the BrdU(+) GFAP(+) cells relative to the BrdU(+) cells did not show any major difference between the control and completely RMS-lesioned sides. This study revealed differences in neurogenesis and gliogenesis between the local and migrating neural stem cells in the OB of the adult rodent.
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Affiliation(s)
- N Fukushima
- Department of Anatomy, Shinshu University School of Medicine, Matsumoto 390-8621, Japan
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Li Z, Kato T, Kawagishi K, Fukushima N, Yokouchi K, Moriizumi T. Cell dynamics of calretinin-immunoreactive neurons in the rostral migratory stream after ibotenate-induced lesions in the forebrain. Neurosci Res 2002; 42:123-32. [PMID: 11849731 DOI: 10.1016/s0168-0102(01)00314-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It is now apparent that adult neurogenesis is taking place during life in the olfactory bulb (OB) of the rodent brain. In the olfactory nervous system, the precursor cells of the subventricular zone are known to continually proliferate, migrate through the rostral migratory stream (RMS) and differentiate into the bulbar neurons. The RMS, consisting of heterogeneous cell populations of the neural and neuronal precursor cells, is the unique forebrain structure that provides a long-distance migratory route for the precursor cells. The present study was undertaken to examine whether neuronal regeneration, focusing on calretinin-immunoreactive (+) cells, may proceed in the RMS following lesions induced by an excitotoxin. Two days after ibotenate injections, massive degeneration of calretinin (+) cells occurred in the RMS and its adjacent forebrains. Thereafter, calretinin (+) cells gradually increased in the RMS and reached above their control value 2 weeks after ibotenate injections. Removal of the OB also produced a marked increase in calretinin (+) cells in the RMS. Autoradiographic experiments using (3)H-thymidine showed that calretinin (+) cells were continually generated in the RMS and underwent neuronal turnover within 8 weeks in a normal condition. The results indicate that, in terms of calretinin (+) cells, neuronal differentiation and replacement is continually taking place within the RMS, and that the RMS is capable of repopulating those cells which were injured by ibotenate.
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Affiliation(s)
- Z Li
- Department of Anatomy, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan
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Fukushima N, Oikawa S, Yokouchi K, Kawagishi K, Moriizumi T. The minimum number of neurons in the central olfactory pathway in relation to its function: a retrograde fiber tracing study. Chem Senses 2002; 27:1-6. [PMID: 11751461 DOI: 10.1093/chemse/27.1.1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The present study was aimed at determining the functionally essential size of the neuronal population in the central olfactory nervous system. Using conditioned rats who had learnt to avoid repellent (cycloheximide) solution by olfaction, varying degrees of injuries were made to the lateral olfactory tract, a major central olfactory pathway connecting the olfactory bulb to the olfactory cortex. After examining their olfactory ability to discriminate cycloheximide solution from water, intact bulbar projection neurons (mitral cells) with fiber connections to the olfactory cortex were quantified using a retrograde fiber tracing technique. The numbers of retrogradely labeled mitral cells from the rats with normal olfaction ranged between 20 and 92% of the control value, while those numbers from the anosmic rats ranged between 0 and 22%. We conclude that the functionally essential neuronal population is approximately one-fifth of the total in the central olfactory pathway, a presumed threshold value in terms of the ability to avoid cycloheximide solution by olfactory discrimination.
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Affiliation(s)
- N Fukushima
- Department of Anatomy, Shinshu University School of Medicine, Matsumoto 390-8621, Japan
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Abstract
It has been known that stem cells do exist in the central nervous system, and adult neurogenesis is continually taking place in the olfactory bulb during life. We report here, with the combined method of autoradiography using (3)H-thymidine and immunohistochemistry for a neuronal marker, that 65.3-76.9% of calretinin-immunoreactive bulbar neurons are replaced during the short period of 6 weeks in the adult rodent. The results indicate that neuronal replacement is a common phenomenon in the olfactory bulb during life.
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Affiliation(s)
- T Kato
- Department of Anatomy, Shinshu University School of Medicine, Matsumoto 390-8621, Japan
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Abstract
It is well established that olfactory receptor cells are replaced during life. Periglomerular (PG) cells of the olfactory bulb have recently been demonstrated to be produced following proliferation and migration of periventricular neuronal precursor cells even in adulthood. The purpose of the present study was to examine the fate of newly formed PG cells in adult rodents. Using 5-bromodeoxyuridine (BrdU), we carried out a quantitative immunohistochemical analysis of BrdU-positive cells in the bulbar glomerular layer at different survival periods. Each number of BrdU-positive PG cells per 100 olfactory glomeruli was 34.1 +/- 3.3 (1 week), 57.2 +/- 2.7 (2 weeks), 28.0 +/- 4.7 (4 weeks) and 25.9 +/- 1.6 (8 weeks). These results indicate that bulbar PG cells, similar to olfactory receptor cells, are mostly replaced during life, and that the olfactory system is composed of disposable neuronal networks centrally as well as peripherally.
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Affiliation(s)
- T Kato
- Department of Anatomy, School of Medicine, Shinshu University, Matsumoto, Japan
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Abstract
The purpose of the present study was to examine immunohistochemically the expression of nestin and polysialylated neural cell adhesion molecule in calretinin-immunoreactive neurons of the rostral migratory stream, the restricted pathway through which neuronal precursor cells migrate towards the olfactory bulb. Using mirror sectioning, calretinin-immunoreactive neurons of the rostral migratory stream were shown to co-express nestin (20.8%) and polysialylated neural cell adhesion molecule (61.8%). The results show that calretinin-immunoreactive neurons in the rostral migratory stream still express immature neural and neuronal phenotypes.
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Affiliation(s)
- T Kato
- Department of Anatomy, Shinshu University School of Medicine, Matsumoto, Japan
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