Itch is an unpleasant sensation that provokes the desire to scratch. While acute itch serves as a protective system to warn the body of external irritating agents, chronic itch is a debilitating but poorly-treated clinical disease leading to repetitive scratching and skin lesions. However, the neural mechanisms underlying the pathophysiology of chronic itch remain mysterious. Here, we identified a cell type-dependent role of the anterior cingulate cortex (ACC) in controlling chronic itch-related excessive scratching behaviors in mice. Moreover, we delineated a neural circuit originating from excitatory neurons of the ACC to the ventral tegmental area (VTA) that was critically involved in chronic itch. Furthermore, we demonstrate that the ACC→VTA circuit also selectively modulated histaminergic acute itch. Finally, the ACC neurons were shown to predominantly innervate the non-dopaminergic neurons of the VTA. Taken together, our findings uncover a cortex-midbrain circuit for chronic itch-evoked scratching behaviors and shed novel insights on therapeutic intervention.
Mice ; Animals ; Gyrus Cinguli/physiology* ; Pruritus/pathology* ; Mesencephalon ; Cerebral Cortex/pathology* ; Neurons/pathology*

Brainstem glimas are common intracranial tumors in young age and have dismal prognosis despite the advance in diagnostic and treatment modalities. The purpose of this study is to classify the brainstem gliomas by growth patterns and to correlate the growth patterns with histological findings. With these results,we have studied further to verify the prognostic factors in brainstem gliomas. Sixty four patients with brainstem gliomas were treated between May, 1989 and March, 1997. For the location of brainstem gliomas, 41 cases were in pons, 13 cases in medulla, 8 cases in midbrain, and 2 disseminated cases. Operations were performed in 44 cases of these lesions which were focally enhanced type or had exophytic growth patterns. Histological diagnoses were low grade gliomas in 22 cases and high grade gliomas in 21 cases. Among them, radiotherapy was performed in 39 patients with diffuse or disseminated type. Among operated pateints, seven were treated with Gamma Knife radiosurgery for focal residual lesion. Diffuse types were more common in pons. Exophytic or focal types were common in medulla and midbrain. High grade glioma was more common in diffuse type and low grade glioma was common in exophytic or focal type. We concluded that the favorable prognostic factors are long duration of symptoms(>2mos), exophytic type, low grade glioma, and radiotherapy treatment.
Brain Stem* ; Classification* ; Diagnosis ; Glioma* ; Humans ; Mesencephalon ; Pathology ; Pons ; Prognosis* ; Radiosurgery ; Radiotherapy

The habenula is a small and bilateral nucleus above dorsal thalamus, which contains several different types of neurons. The habenula has extensive connections with the forebrain, septum and monoaminergic nuclei in the midbrain and brainstem. Habenula is known as an 'anti-reward' nucleus, which can be activated by aversive stimulus and negative reward prediction errors. Accumulating researchs have implicated that the habenula is involved in several behaviors crucial to survival. Meanwhile, the roles of the habenula in neuropsychiatric diseases have received increasing attention. This review summaries the studies regarding the roles of habenula and the related circuits in neuropathic pain, depression, drug addiction and schizophrenia, and discusses the possibility to use the habenula as a treatment target.
Depressive Disorder ; Habenula ; Humans ; Mental Disorders ; pathology ; Mesencephalon ; Neurons ; metabolism ; Reward

OBJECTIVETo analyze the clinical characteristics and surgery approach for patients with brainstem cavernous malformation (BSCM).

METHODSThe clinical data of 23 BSCM patients (5 cases at midbrain, 16 cases at pons, and 2 cases at medulla) treated in the Second Affiliated Hospital Zhejiang University School of Medicine from July 2003 to June 2014 were retrospectively reviewed. The medical history, radiological findings, operation records, postoperative course and follow-up results were analyzed.

RESULTSSuboccipital approach, retrosigmoid approach, subtentorial supracerebella approach, Poppen approach, pterional approach, Kawase approach, interhemispheric transcallosal third ventrical approach were applied for the surgery of BSCM patients. Among them, Kawase approach and interhemispheric transcallosal third ventrical approach were firstly reported in treatment of BSCM. Total resection was achieved in 22 cases. Neurological function was improved in 15 cases, unchanged in 7 cases and deteriorated in 1 case. Fifteen cases were followed up for a mean period of 3.5 years and signs of recurrence was found.

CONCLUSIONProper selection of surgical approach is important to assure total resection of the lesions, to protect surrounding normal vital structures and to avoid post-surgical complications.

Humans ; Medulla Oblongata ; pathology ; surgery ; Mesencephalon ; pathology ; surgery ; Neurosurgical Procedures ; methods ; Pons ; pathology ; surgery ; Postoperative Period ; Recurrence ; Retrospective Studies ; Treatment Outcome

PURPOSE: To describe the magnetic resonance (MR) imaging findings of hypertrophic olivary degeneration (HOD). MATERIALS AND METHODS: MR images of seven patients with HOD were retrospectively reviewed. Two were women and five were men, and they were aged between 48 and 65 (mean 58) years. Imaging examinations were performed with a 1.5-T unit, and the findings were used to evaluate the size and signal intensity of olivary lesions. The time interval from hemorrhagic ictus to MR imaging was between two and 30 months. Follow-up examinations were performed in two patients. RESULTS: All four patients with hemorrhages involving the central tegmental tract in the pons or midbrain showed ipsilateral HOD. Among these four, bilateral HOD was seen in one patient with hemorrhage involving the bilateral central tegmental tract, and in another with tegmental hemorrhage extending to the ipsilateral superior cerebellar peduncle. One patient with cerebellar hemorrhage involving the dentate nucleus had contralateral HOD. Two patients with multiple hemorrhages involving both the pons and cerebellum showed bilateral HOD. Axial MR images showed mild enlargement of the involved olivary nucleus, with high signal intensity on both proton density and T2 weighted images. There was no apparent enhancement on postcontrast T1-weighted images. CONCLUSION: MR imaging can clearly distinguish secondary olivary degeneration from underlying pathology involving the central tegmental tract in the pons or midbrain and cerebellum. These olivary abnormalities should not, however, be mistaken for primary medullary lesions.
Cerebellar Nuclei ; Cerebellum ; Female ; Follow-Up Studies ; Hemorrhage ; Humans ; Magnetic Resonance Imaging* ; Male ; Mesencephalon ; Olivary Nucleus ; Pathology ; Pons ; Protons ; Retrospective Studies

BACKGROUND: To investigate postoperative changes in the cerebral glucose metabolism of patients with mesial temporal lobe epilepsy (MTLE), statistical parametric mapping (SPM) analysis was performed on pre- and post-operative 18F-fluorodeoxy glucose positron emission tomographic (FDG-PET) images. METHODS: We included 28 patients with MTLE who had under-gone surgery and had been seizure free postoperatively (16 had left MTLE and 12 right MTLE). All patients showed hippocampal sclerosis by pathology or brain MRI. FDG-PET images of the 12 right TLE patients were reversed to lateralize the epileptogenic zone to the left side in all patients. RESULTS: Application of the paired t-test in SPM to pre- and postoperative FDG-PETs showed that the postoperative glucose metabolism decreased in the caudate nucleus, pulvinar of thalamus, fusiform gyrus, lingual gyrus, and in the posterior region of the insular cortex in the hemisphere ipsilateral to resection, whereas postoperative glucose metabolism increased in the anterior region of the insular cortex, temporal stem white matter, midbrain, inferior precentral gyrus, anterior cingulate gyrus, and supramarginal gyrus in the hemisphere ipsilateral to resection. No significant postsurgical changes of cerebral glucose metabolism occurred in the contralateral hemisphere. Subtraction between pre- and postoperative FDG-PET images in individual patients produced similar findings to the SPM results. CONCLUSION: This study suggests that brain regions showing a postoperative increase in glucose metabolism appear to represent the propagation pathways of ictal and interictal epileptic discharges in MTLE while a postoperative decrease in glucose metabolism may be related to a permanent loss of afferents from resected anterior-mesial temporal structures.
Anterior Temporal Lobectomy ; Brain ; Caudate Nucleus ; Electrons ; Epilepsy, Temporal Lobe* ; Glucose ; Gyrus Cinguli ; Humans ; Magnetic Resonance Imaging ; Mesencephalon ; Metabolism ; Pathology ; Pulvinar ; Sclerosis ; Seizures ; Temporal Lobe* ; Thalamus

Sixty years ago, Steele, Richardson and Olszewski designated progressive supranuclear palsy (PSP) as a new clinicopathological entity in their seminal paper. Since then, in addition to the classic Richardson's syndrome (RS), different clinical phenotypic presentations have been linked with this four-repeat tauopathy. The clinical heterogeneity is associated with variability of regional distribution and severity of abnormal tau accumulation and neuronal loss. In PSP subtypes, the presence of certain clinical pointers may be useful for antemortem prediction of the underlying PSP-tau pathology. Midbrain atrophy on conventional MRI correlates with the clinical phenotype of RS but is not predictive of PSP pathology. Cerebrospinal fluid biomarkers and tau ligand positron emission tomography are promising biomarkers of PSP. A multidisciplinary approach to meet the patients' complex needs is the current core treatment strategy for this devastating disorder.
Atrophy ; Biomarkers ; Cerebrospinal Fluid ; Magnetic Resonance Imaging ; Mesencephalon ; Neurons ; Pathology ; Phenotype ; Population Characteristics ; Positron-Emission Tomography ; Steel ; Supranuclear Palsy, Progressive* ; Tauopathies

In recent years, several radiotracers that selectively bind to pathological tau proteins have been developed. Evidence is emerging that binding patterns of in vivo tau positron emission tomography (PET) studies in Alzheimer's disease (AD) patients closely resemble the distribution patterns of known neurofibrillary tangle pathology, with the extent of tracer binding reflecting the clinical and pathological progression of AD. In Lewy body diseases (LBD), tau PET imaging has clearly revealed cortical tau burden with a distribution pattern distinct from AD and increased cortical binding within the LBD spectrum. In progressive supranuclear palsy, the globus pallidus and midbrain have shown increased binding most prominently. Tau PET patterns in patients with corticobasal syndrome are characterized by asymmetrical uptake in the motor cortex and underlying white matter, as well as in the basal ganglia. Even in the patients with multiple system atrophy, which is basically a synucleinopathy, ¹⁸F-flortaucipir, a widely used tau PET tracer, also binds to the atrophic posterior putamen, possibly due to off-target binding. These distinct patterns of tau-selective radiotracer binding in the various degenerative parkinsonisms suggest its utility as a potential imaging biomarker for the differential diagnosis of parkinsonisms.
Alzheimer Disease ; Basal Ganglia ; Diagnosis, Differential ; Electrons ; Globus Pallidus ; Humans ; Lewy Bodies ; Mesencephalon ; Motor Cortex ; Multiple System Atrophy ; Neurofibrillary Tangles ; Parkinsonian Disorders ; Pathology ; Positron-Emission Tomography ; Putamen ; Supranuclear Palsy, Progressive ; tau Proteins ; White Matter

OBJECTIVETo identify the protective effect of lipopolysaccharide (LPS) preconditioning against LPS-induced inflammatory damage in dopaminergic neurons of midbrain slice culture and the possible mechanisms.

METHODSAfter cultured in vitro for 14 d, the rat organotypic midbrain slices were pretreated with different concentrations (0, 1, 3, 6 or 10 ng/mL) of LPS for 24 h followed by treatment with 100 ng/mL LPS for 72 h. The whole slice viability was determined by measurement of the activity of lactic acid dehydrogenase (LDH). Tyrosine hydroxylase-immunoreactive (TH-IR) neurons and CD11b/c equivalent-immunoreactive (OX-42-IR) microglia in the slices were observed by immunohistochemical method, and tumor necrosis factor-alpha (TNF-alpha) levels in the culture media were detected by enzyme-linked immunosorbent assays (ELISA).

RESULTSIn the slices treated with 100 ng/mL LPS for 72 h, the number of TH-IR neurons reduced from 191+/-12 in the control slices to 46+/-4, and the LDH activity elevated obviously (P < 0.01), along with remarkably increased number of OX-42-IR cells and production of TNF-alpha (P < 0.01). Preconditioning with 3 or 6 ng/mL LPS attenuated neuron loss (the number of TH-IR neurons increased to 126+/-12 and 180+/-13, respectively) and markedly reduced LDH levels (P < 0.05), accompanied by significant decreases of OX-42-IR microglia activation and TNF-alpha production (P < 0.05).

CONCLUSIONLow-dose LPS preconditioning could protect dopaminergic neurons against inflammatory damage in rat midbrain slice culture, and inhibition of microglial activation and reduction of the proinflammatory factor TNF-alpha production may contribute to this protective effect. Further understanding the underlying mechanism of LPS preconditioning may open a new window for treatment of Parkinson's disease.

Animals ; CD11 Antigens ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Immunohistochemistry ; Inflammation ; chemically induced ; pathology ; L-Lactate Dehydrogenase ; metabolism ; Lipopolysaccharides ; administration & dosage ; toxicity ; Mesencephalon ; drug effects ; immunology ; pathology ; Microglia ; drug effects ; immunology ; pathology ; Nerve Degeneration ; metabolism ; pathology ; prevention & control ; Neurons ; drug effects ; immunology ; pathology ; Organ Culture Techniques ; Rats ; Tumor Necrosis Factor-alpha ; metabolism ; Tyrosine 3-Monooxygenase ; metabolism

Two cats were presented with vestibular signs and seizures. Both cats were diagnosed with thiamine deficiency. The transverse and dorsal T2-weighted magnetic resonance (MR) images revealed the presence of bilateral hyperintense lesions at specific nuclei of the midbrain, cerebellum, and brainstem. After thiamine supplementation, the clinical signs gradually improved. Repeated MR images taken 3 weeks after thiamine supplementation had started showed that the lesions were nearly resolved. This case report describes the clinical and MR findings associated with thiamine deficiency in two cats.
Animals ; Brain Stem/pathology ; Cat Diseases/chemically induced/*diagnosis/*drug therapy ; Cats ; Cerebellum/pathology ; Diet/veterinary ; Dietary Supplements/analysis ; Female ; Magnetic Resonance Imaging/veterinary ; Male ; Mesencephalon/pathology ; Seizures/chemically induced/pathology/veterinary ; Thiamine/administration & dosage/*therapeutic use ; Thiamine Deficiency/chemically induced/diagnosis/drug therapy/*veterinary ; Treatment Outcome