Unlabelled: Although injured axons usually do not regenerate in the adult CNS, parallel fibers (PFs) regenerate synaptic connections onto cerebellar Purkinje cells (PCs). In this study, we investigated the role of GluD2 in this regenerative process after PF transection using GluD2-knock-out (KO) mice. All dendritic spines on distal dendrites were innervated by PFs in sham-operated wild-type controls, whereas one-third were devoid of innervation in GluD2-KO mice.
View Article and Find Full Text PDFIn Purkinje cells (PCs) of the cerebellum, a single "winner" climbing fiber (CF) monopolizes proximal dendrites, whereas hundreds of thousands of parallel fibers (PFs) innervate distal dendrites, and both CF and PF inputs innervate a narrow intermediate domain. It is unclear how this segregated CF and PF innervation is established on PC dendrites. Through reconstruction of dendritic innervation by serial electron microscopy, we show that from postnatal day 9-15 in mice, both CF and PF innervation territories vigorously expand because of an enlargement of the region of overlapping innervation.
View Article and Find Full Text PDFIn early postnatal development, perisomatic innervation of cerebellar Purkinje cells (PCs) switches from glutamatergic climbing fibers (CFs) to GABAergic basket cell fibers (BFs). Here we examined the switching process in C57BL/6 mice. At postnatal day 7 (P7), most perisomatic synapses were formed by CFs on to somatic spines.
View Article and Find Full Text PDFFunctional neural circuits are formed by eliminating early-formed redundant synapses and strengthening necessary connections during development. In newborn mouse cerebellum, each Purkinje cell (PC) is innervated by multiple climbing fibers (CFs) with similar strengths. Subsequently, a single CF is selectively strengthened by postnatal day 7 (P7).
View Article and Find Full Text PDFPhysiological studies have shown that lower urinary tract function is regulated through glutamate receptors at the levels of spinal and supraspinal cord. Of the receptor family, N-methyl-D-aspartate (NMDA) receptors mediate activity-dependent changes of synaptic efficacy, underlying synaptic plasticity and synapse development. To know the ontogenic changes of NMDA receptor expression in the visceromotor system innervating pelvic organs, including the bladder, we employed double labeling technique of retrograde neuronal tracing and in situ hybridization for detecting NMDA subunit mRNAs in preganglionic neurons (PGNs) of the lumbosacral cord.
View Article and Find Full Text PDFEstrogen status is known to affect the incidence of cardiovascular disease. Experiments were designed to prove the influences of in vivo estrogen manipulations on vascular hyperpolarization and relaxation mediated by endothelium-derived hyperpolarizing factor (EDHF), and to explore the possible mechanism contributing to the altered EDHF responses in estrogen-deficient states. Mesenteric arteries with intact endothelium were isolated from sham-operated (control), ovariectomized (OVX), or OVX with 17beta-estradiol replacement (OVX + E ) female rats.
View Article and Find Full Text PDFOrganized synapse formation on to Purkinje cell (PC) dendrites by parallel fibers (PFs) and climbing fibers (CFs) is crucial for cerebellar function. In PCs lacking glutamate receptor delta2 (GluRdelta2), PF synapses are reduced in number, numerous free spines emerge, and multiple CF innervation persists to adulthood. In the present study, we conducted anterograde and immunohistochemical labelings to investigate how CFs innervate PC dendrites under weakened synaptogenesis by PFs.
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