Über die Tanzmaus (Bericht 2.) Vergleichend-anatomische Untersuchung der Gehörorgane des Ohrlabyrinthes bei der Tanzmaus und bei der gewöhnlichen Maus

Verfasser stellte über die Hörfunktion bei den erwachsenen Tanzmäusen mit verschiedenen Schallreizen Untersuchungen an. Nachdem er konstatiert hatte, dass die Tanzmäuse total taub sind, fixierte er das Gehörorgan der Mäuse vital und nachfixierte es dann um mikroskopische Präparate anzufertigen. Das Herausnehmen des Modiolus geschah nach Tanakascher Methode. Serienschnitt parallel der Längsachse des Modiolus; jeder Schnitt 15-20μ. Auf diese Weise kam Verfasser zu Resultaten, die von denen der bisherigen Forscher etwas abweichen. 1) Bei der Tanzmaus findet keine Reaktion gegen verschiedene Schallreize statt, sie ist also taub. 2) Die Tiere, bei denen durch die Strychnininjektion jeder Reflex stark gesteigert ist, sind gegen Schallreize ganz reaktionslos. 3) In der Schnecke der Tanzmaus findet man in jeder Windung das Cortische Organ vollkommen, ihre Sinneszellen und Stützzellen sind also unverändert. 4) Man sieht an den Zellen des Ganglion spirale eine Primäre Entartung und auch an den denselben beigefügten Intraspiralnervenfasern eine Veränderung. Diese Veränderungen sind in der Basalwindung der Schnecke am auffallendsten und werden um so unbedeutender, je näher ihre Stelle der oberen Windung liegt. 5) Die Veränderungen an den Zellen des Ganglion spirale sind deutlicher als die in den Ganglienzellen des Vorhofes

Glial cell line-derived neurotrophic factor (GDNF) therapy for Parkinson's disease.

Many studies using animals clarify that glial cell line-derived neurotrophic factor (GDNF) has strong neuroprotective and neurorestorative effects on dopaminergic neurons. Several pilot studies clarified the validity of continuous intraputaminal GDNF infusion to patients with Parkinson's disease (PD), although a randomized controlled trial of GDNF therapy published in 2006 resulted in negative outcomes, and controversy remains about the efficacy and safety of the treatment. For a decade, our laboratory has investigated the efficacy and the most appropriate method of GDNF administration using animals, and consequently we have obtained some solid data that correspond to the results of clinical trials. In this review, we present an outline of our studies and other key studies related to GDNF, the current state of the research, problems to be overcome, and predictions regarding the use of GDNF therapy for PD in the future.</p

Animal Models for Parkinson's Disease Research: Trends in the 2000s

Parkinson's disease (PD) is a chronic and progressive movement disorder and the second most common neurodegenerative disease. Although many studies have been conducted, there is an unmet clinical need to develop new treatments because, currently, only symptomatic therapies are available. To achieve this goal, clarification of the pathology is required. Attempts have been made to emulate human PD and various animal models have been developed over the decades. Neurotoxin models have been commonly used for PD research. Recently, advances in transgenic technology have enabled the development of genetic models that help to identify new approaches in PD research. However, PD animal model trends have not been investigated. Revealing the trends for PD research will be valuable for increasing our understanding of the positive and negative aspects of each model. In this article, we clarified the trends for animal models that were used to research PD in the 2000s, and we discussed each model based on these trends

Mesenchymal Stem Cell Therapy for Ischemic Stroke

　To date, many animal studies have indicated the neuroprotective effects of mesenchymal stem cell (MSC) transplantation in ischemic stroke. Several clinical studies have also revealed the safety, feasibility, and neuroprotective effects in ischemic stroke patients. In this review, we present the main approaches of MSC transplantation in ischemic stroke, the mechanisms of MSC therapy, and the current clinical studies on MSC transplantation in ischemic stroke patients. We also explore the safety of MSC transplantation and conclude that MSC therapy will play an important role in the future treatment of ischemic stroke. The optimal timing, approach, and cell dose in the transplantation are important issues for successful clinical application

Chiari Malformation with Thick Occipital Bone

A case of a Chiari malformation with an extraordinarily thick occipital bone is described. The thick occipital bone might make the posterior fossa narrow with consequent herniation of the cerebellar tonsils to the foramen magnum and formation of a syrinx. At dural plasty, well-developed marginal and occipital sinuses should be deliberately handled with the preservation of normal venous drainage. This case gives us the essence of the occurrence mechanisms of Chiari malformation and foramen magnum decompression

Precise MEP monitoring with a reduced interval is safe and useful for detecting permissive duration for temporary clipping

Although temporary clipping of the parent artery is an indispensable technique in clipping surgery for intracranial aneurysms, the permissive duration of temporary clipping is still not well known. The aim of this study is to confirm the safety of precise motor evoked potential (MEP) monitoring and to estimate the permissive duration of temporary clipping for middle cerebral artery (MCA) aneurysm based on precise MEP monitoring results. Under precise MEP monitoring via direct cortical stimulation every 30 seconds to 1 minute, surgeons released a temporary clip and waited for MEP amplitude to recover following severe (>50%) reduction of MEP amplitude during temporary clipping. Precise MEP monitoring was safely performed. Twenty-eight instances of temporary clipping were performed in 42 MCA aneurysm clipping surgeries. Because precise MEP monitoring could be used to determine when to release a temporary clip even with a severe reduction in MEP amplitude due to lengthy temporary clipping, no patients experienced permanent postoperative hemiparesis. Based on logistic regression analysis, if a temporary clip is applied for 312 seconds or more, there is a higher probability of a severe reduction in MEP amplitude. We should therefore release temporary clips after 5 minutes in order to avoid permanent postoperative hemiparesis

A Rare Case of Idiopathic Spinal Cord Herniation Treated by DuraGen® Collagen Matrix Graft

We report a rare case of idiopathic spinal cord herniation (ISCH) with a history of cerebrospinal fluid (CSF) leakage. ISCH is a protrusion of the spinal cord through a dural defect. Thin constructive interference in steady-state (CISS) images clearly demonstrated the herniated cord in the present case. The myelopathy worsened and the patient underwent surgery for reduction of herniated spinal cord; the dural defect was filled by placing collagen matrix graft (DuraGen®) between the inner and outer dural layers. The patient’s symptoms have improved without relapse for 8 months since surgery. This method may be a good surgical option for cases of spinal cord herniation

A Pediatric Case of Cauda Equina Dermoid Cyst Resected by Minimally Invasive Unilateral Hemilaminectomy

A 3-year-old boy had difficulty sitting up and walking for several months. Magnetic resonance imaging (MRI) revealed an intradural tumor at the L3-4 level. The tumor was successfully resected by unilateral hemilaminectomy and diagnosed as dermoid cyst. The patient had an uneventful postoperative course without pain, and MRI found no recurrence after surgery. A small bone defect remained that might be favorably reconstructed with autologous and artificial bone. Hemilaminectomy allowed us to resect the cauda equina dermoid cyst with minimal invasiveness. Pediatric patients require follow-up as they are more likely to experience spinal deformity or instability after surgery

Spinal Extradural Arachnoid Cyst: Significance of Intrathecal Infusion after Fistula Closure

The spinal extradural arachnoid cyst is a rare entity. Obtaining the correct diagnosis and detecting the fistula location are critical for providing effective treatment. A 41-year-old man had numbness in the soles of his feet for 2 years with accompanying gait disturbance, and a defecation disorder. Computed tomography myelography performed at another hospital revealed an epidural arachnoid cyst from Th11 to L2. He received a subarachnoid-cyst shunt at the rostral part of the cyst. However, his symptoms worsened and he was admitted to our hospital. Neuroradiological investigations revealed the correct location of the fistula at the level of Th12. We performed partial removal of the cyst wall with fistula closure via right hemilaminectomy of Th11 and 12. The complete closure of the fistula was confirmed by intrathecal infusion of artificial cerebrospinal fluid through the shunt tube. The shunt tube was removed with the sutures. The patient’s symptoms improved, although numbness remained in his bilateral heels. There has been no recurrence in 15 months since the surgery. Fistula closure may work as a balanced therapeutic strategy for spinal extradural arachnoid cyst, and intrathecal cerebrospinal fluid infusion is useful for the confirmation of complete fistula closure