Adolescent ; Cerebellar Cortex ; metabolism ; pathology ; Cerebellar Neoplasms ; metabolism ; pathology ; surgery ; Female ; Follow-Up Studies ; Ganglioneuroma ; metabolism ; pathology ; surgery ; Humans ; Neurofilament Proteins ; metabolism ; Synaptophysin ; metabolism

Cerebellar Purkinje cells (PCs) exhibit two types of discharge activities: simple spike (SS) and complex spike (CS). Previous studies found that noradrenaline (NA) can inhibit CS and bidirectionally regulate SS, but the enhancement of NA on SS is overwhelmed by the strong inhibition of excitatory molecular layer interneurons. However, the mechanism underlying the effect of NA on SS discharge frequency is not clear. Therefore, in the present study, we examined the mechanism underlying the increasing effect of NA on SS firing of PC in mouse cerebellar cortex in vivo and in cerebellar slice by cell-attached and whole-cell recording technique and pharmacological methods. GABA_A receptor was blocked by 100 µmol/L picrotoxin in the whole process. In vivo results showed that NA significantly reduced the number of spikelets of spontaneous CS and enhanced the discharge frequency of SS, but did not affect the discharge frequency of CS. In vitro experiments showed that NA reduced the number of CS spikelets and after hyperpolarization potential (AHP) induced by electrical stimulation, and increased the discharge frequency of SS. NA also reduced the amplitude of excitatory postsynaptic current (EPSC) of parallel fiber (PF)-PC and significantly increased the paired-pulse ratio (PPR). Application of yohimbine, an antagonist of α2-adrenergic receptor (AR), completely eliminated the enhancing effect of NA on SS. The α2-AR agonist, UK14304, also increased the frequency of SS. The β-AR blocker, propranolol, did not affect the effects of NA on PC. These results suggest that in the absence of GABA_A receptors, NA could attenuate the synaptic transmission of climbing fiber (CF)-PC via activating α2-AR, inhibit CS activity and reduce AHP, thus enhancing the SS discharge frequency of PC. This result suggests that NA neurons of locus coeruleus can finely regulate PC signal output by regulating CF-PC synaptic transmission.
Action Potentials/physiology* ; Animals ; Cerebellar Cortex/metabolism* ; Cerebellum/metabolism* ; Mice ; Norepinephrine/pharmacology* ; Purkinje Cells/metabolism* ; Receptors, Adrenergic, alpha-2/metabolism* ; Receptors, GABA-A/metabolism*

OBJECTIVETo investigate the growth and development of nitric oxide synthase (NOS)-positive neurons in the cerebellum of human fetus in the midanaphase.

METHODThe positive expression of the NOS-positive neurons in the cerebellum of midanaphase human fetus was observed by immunohistochemistry.

RESULTSBy the sixth to seventh month of gestation, NOS-positive neurons were seen in the ependymal layer of the cerebellum. The nucleus was oval-shaped and the neurons had short and small processes. By the eighth to ninth month, NOS-positive neurons were found in the central layer of the cerebellum and the nucleus was round-, oval-, or fusiform-shaped; meanwhile, the neurons grew larger in size with richer cytoplast and heavier staining. The beaded nerve fibers reached the marginal layer and the layer became thickened on the tenth month, which generally was composed of 5 to 6 layers of NOS-positive neurons that were tightly aligned. Some NOS-positive neurons were in smaller size with the cell body and the nerve fibers grew well.

CONCLUSIONNitric oxide generated by NOS of the NOS-positive neurons in the cerebellum plays an important role in the differentiation, proliferation, and migration of neurons and gliacytes.

Cerebellar Cortex ; Fetus ; physiology ; Humans ; Immunohistochemistry ; Nerve Fibers ; Neurons ; cytology ; metabolism ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase ; metabolism ; Nitric Oxide Synthase Type I

BACKGROUND: Overlapping clinical features of idiopathic Parkinson's disease (IPD) and multiple system atrophy (MSA) make it difficult to conduct an accurate differential diagnosis. We performed a quantitative F18- fluorodeoxyglucose PET (FDG PET) and measured the striatal and cerebellar glucose metabolism to evaluate the efficacy of a FDG PET study in the differential diagnosis between IPD and MSA. METHODS: This study included 19 patients with IPD, 28 patients with MSA (MSA-P : MSA-C = 19 : 9) and 12 age matched normal controls. A FDG PET study was performed in all subjects and the original PET image was corrected with the radioactivity curve obtained by repetitive sampling of the radial arterial blood. RESULTS: The measurements of striatal and cerebellar glucose metabolisms of the patients with MSA-P were significantly lower than those of the patients with IPD (P<0.001). However, the measurement of the caudate nucleus provided the most reliable clue for the differential diagnosis between IPD and MSA-P (sensitivity 94.7% and specificity 94.7%). In the patients with MSA-C, the glucose metabolism of the cerebellar vermis (P<0.001), cerebellar cortex (P<0.001) and putamen (P<0.05) was significantly lower than those of the patients with IPD. CONCLUSIONS: Quantitative FDG PET is a useful and reliable method in making a differential diagnosis between IPD and MSA.
Caudate Nucleus ; Cerebellar Cortex ; Cerebellum ; Corpus Striatum ; Diagnosis, Differential* ; Fluorodeoxyglucose F18 ; Glucose ; Humans ; Metabolism ; Multiple System Atrophy* ; Parkinson Disease* ; Positron-Emission Tomography ; Putamen ; Radioactivity ; Sensitivity and Specificity