The anterior testicular ducts of squamates transport sperm from the seminiferous tubules to the ductus deferens. These ducts consist of the rete testis, ductuli efferentes, and ductus epididymis. Many histological and a few ultrastructural studies of the squamate reproductive tract exist, but none concern the Hydrophiidae, the sea snakes and ...

Glutamate receptor GluRδ2 is exclusively expressed in Purkinje cells (PCs) from early development and plays key roles in parallel fiber (PF) synapse formation, elimination of surplus climbing fibers (CFs), long-term depression, motor coordination, and motor learning. To address its role in adulthood, we previously developed a mouse model of drug-induced ...

The molecular pathways controlling cerebellar Purkinje cell dendrite formation and maturation are poorly understood. The Purkinje cell degeneration (pcd) mutant mouse is characterized by mutations in Nna1, a gene discovered in an axonal regenerative context, but whose actual function in development and disease is unknown. We found abnormal development of ...

Nonquantitative studies indicate that the cerebellum is neuropathologically affected in Alzheimer's disease; however, no quantitative studies on the subject have yet been conducted. Ten cerebella from elderly female subjects with severe Alzheimer's disease and 10 age- and gender-matched controls were examined. The cerebellum was divided into 5 regions and the ...

PURPOSE: The World Health Organisation proposed an investigation concerning the exposure of animals to radiofrequency fields because of the possible risk factor for health. At power frequencies there is evidence to associate both childhood leukaemia and brain tumours with magnetic field exposures. There is also evidence of the effect of ...

Several C1q family members, especially the Cbln and C1q-like subfamilies, are highly and predominantly expressed in the central nervous system. Cbln1, a member of the Cbln subfamily, plays two unique roles at parallel fiber (PF)-Purkinje cell synapses in the cerebellum: the formation and stabilization of synaptic contact, and the control ...

Cerebellar feedforward inhibition (FFI) is mediated by two distinct pathways targeting different subcellular compartments of Purkinje cells (PCs). The axon of the granule cell, the parallel fiber, makes excitatory synapses not only onto PCs but also onto two types of interneurons, basket and stellate cells. Basket and stellate cells then ...

The spatial organization of the mouse cerebellum into transverse zones and parasagittal stripes is reflected during the temporal progression of Purkinje cell death in the Lurcher mutant mouse (+/Lc). Neurodegeneration in the +/Lc mutant is apparent by the second postnatal week and is initially seen in all four transverse zones: ...

The recoding of diverse sensory and motor signals by granule cells (GCs) is probably critical for the function of cerebellar circuits, yet the nature of these transformations and their significance for cerebellar information processing remain poorly understood. In cerebellum-like structures in fish, anti-Hebbian plasticity at parallel fiber synapses generates "negative ...

Purkinje cells in the mammalian cerebellum are remarkably homogeneous in shape and orientation, yet they exhibit regional differences in gene expression. Purkinje cells that express high levels of zebrin II (aldolase C) and the glutamate transporter EAAT4 cluster in parasagittal zones that receive input from distinct groups of climbing fibers ...

The present study examined the spatial organization of tyrosine hydroxylase (TH) immunopositive Purkinje cells in the cerebellum of rolling mouse Nagoya with reference to the distribution pattern of the cerebellar compartmentation antigen, heat shock protein 25 (HSP25). Whole-mount immunostaining revealed a striking pattern of parasagittal stripes of TH staining in ...

The present study aimed at identifying early damage index in the cerebellum following total body irradiation (TBI). Adult male CD2F1 mice (n=18) with or without TBI challenge (8.5 Gy irradiation) were assessed for histology and expression of selected immunohistochemical markers including malondiadehyde (MDA), 8-hydroxy-2'-deoxyguanosine (8-OHdG), protein 53 (p53), vascular endothelial ...

In the present study, we compared the expression of cyclin D2 and D2SV, the cyclin D2 splice variant, in mouse cerebellum at postnatal day 1 (P1), P7, P14 and P28. Western blotting revealed that cyclin D2 levels (34kDa) peaked at P7 and then decreased to levels near the limit of ...

Cerebellar Purkinje cells produce two distinct forms of action potential output: simple and complex spikes. Simple spikes occur spontaneously or are driven by parallel fibre input, while complex spikes are activated by climbing fibre input. Previous studies indicate that both simple and complex spikes originate in the axon of Purkinje ...

Purkinje cell loss by excitotoxic damage is a typical finding in many cerebellar diseases. One important aspect of this high sensitivity of Purkinje cells to excitotoxic death might be the enormous size of their dendritic tree, with a high load of excitatory glutamate receptors. We have studied whether reduction in ...

Essential tremor (ET) is one of the most common neurologic diseases. Increased numbers of torpedoes and Purkinje cell (PC) loss have been documented in the brains of patients with ET. We recently observed a dense and tangled appearance ("hairiness") of the basket cell axonal plexuses that surround PC soma in ...

In the cerebellar cortex, interneurons of the molecular layer (stellate and basket cells) provide GABAergic input to Purkinje cells, as well as to each other and possibly to other interneurons. GABAergic inhibition in the molecular layer has mainly been investigated at the interneuron to Purkinje cell synapse. In this study, ...

The active form (T3) of thyroid hormone (TH) controls critical aspects of cerebellar development, such as migration of postmitotic neurons and terminal dendritic differentiation of Purkinje cells. The effects of T3 on early dendritic differentiation are poorly understood. In this study, we have analyzed the influence of T3 on the ...

Cerebellar corticogenesis begins with the assembly of Purkinje cells into the Purkinje plate (PP) by embryonic day 14.5 (E14.5) in mice. Although the dependence of PP formation on the secreted protein Reelin is well known and a prevailing model suggests that Purkinje cells migrate along the 'radial glial' fibers connecting ...

Somatostatin 28 immunoreactivity (Sst28-ir) identifies a specific subset of mossy fiber terminals in the adult mouse cerebellum. By using double-labeling immunohistochemistry, we determined that Sst28-ir is associated with presynaptic mossy fiber terminal rosettes, and not Purkinje cells, Golgi cells, or unipolar brush cells. Sst28-ir mossy fibers are restricted to the ...

Transverse boundaries divide the mammalian cerebellar cortex into transverse zones, and within each zone the cortex is further subdivided into a symmetrical array of parasagittal stripes. This topography is highly conserved across the Mammalia. Bats have a remarkable cerebellum with presumed adaptations to flight and to echolocation, but nothing is ...

During postnatal cerebellar development, Purkinje cells form the most elaborate dendritic trees among neurons in the brain, which have been of great interest to many investigators. This article overviews various examples of cellular and molecular mechanisms of formation of Purkinje cell dendrites as well as the methodological aspects of investigating ...

The localization of GluR1 subunits of ionotropic glutamate receptors in the glial cells and inhibitory neurons of cerebellar cortex and their association with the climbing and parallel fibers, and basket cell axons were studied. Samples of P14 and P21 rat cerebellar cortex were exposed to a specific antibody against GluR1 ...

Functional 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). We find that this ...

In mammals, climbing fiber axons compete for sole innervation at each Purkinje cell. At the same time, synapses disappear from Purkinje somata and appear in great numbers on the dendrites. In this issue of Neuron, Hashimoto et al. show that, by the time climbing fibers ascend the dendrites, the winner ...

Knowing how different cell types handle glucose should help to decipher how energy supply is adjusted to energy demand in the brain. Previously, the uptake of glucose by cultured brain cells was studied in real-time using fluorescent tracers and confocal microscopy. Here, we have adapted this technique to acute slices ...

The turtle's cerebellum (Cb) is an unfoliated sheet, so the topography of its entire cortex can be easily studied physiologically by optical recordings. However, unlike the mammalian Cb, little is known about the topography of turtle Purkinje cells (PCs). Here, topography was examined using calbindin-D(28K) immunohistochemistry of adult and hatchling ...

Growing physiological evidence suggests that there are functional differences between synapses made by the ascending and parallel fiber segments of the granule axon on cerebellar Purkinje cells. Supporting this view, our previous electron microscopic studies suggested that these synapses also contacted different regions of the Purkinje cell dendrite, and in ...

The pathology of maldronksiekte, a sporadic neurological disorder of cattle caused by the ingestion of the plant Solanum kwebense in certain parts of South Africa, was studied in three chronic field cases. There was loss of cerebellar Purkinje cells with the remaining neurons either swollen or shrunken and showing degeneration ...

Cbln1, which belongs to the C1q/tumor necrosis factor superfamily, is released from cerebellar granule cells and plays a crucial role in forming and maintaining excitatory synapses between parallel fibers (PFs; axons of granule cells) and Purkinje cells not only during development but also in the adult cerebellum. Although neuronal activity ...

The morphology of dissociated single cerebellar Purkinje cells obtained from wild-type P1 CD1 mice was assessed in the absence and in the presence of glia. A dedicated noninvasive technique based on optical microscopy was developed. Image processing algorithms were implemented to extract metrical features characterizing cell structure and dendritic arborization. ...

Cbln1, a glycoprotein secreted from granule cells and GluRdelta2 in the postsynaptic densities of Purkinje cells are components of an incompletely understood pathway essential for integrity and plasticity of parallel fiber-Purkinje cell synapses. We show that Cbln1 undergoes anterograde transport from granule cells to Purkinje cells and Bergmann glia, and ...

Correlated network activity is important in the development of many neural circuits. Purkinje cells are among the first neurons to populate the cerebellar cortex, where they sprout exuberant axon collaterals. We used multiple patch-clamp recordings targeted with two-photon microscopy to characterize monosynaptic connections between the Purkinje cells of juvenile mice. ...

Purkinje cells can encode the strength of parallel fiber inputs in their firing by using 2 fundamentally different mechanisms, either as pauses or as linear increases in firing rate. It is not clear which of these 2 encoding mechanisms is used by the cerebellum. We used the pattern-recognition capacity of ...

AIMS: To determine in the cerebellum in variant Creutzfeldt-Jakob disease (vCJD): (i) whether the pathology affected all laminae; (ii) the spatial topography of the pathology along the folia; (iii) spatial correlations between the pathological changes; and (iv) whether the pathology was similar to that of the common methionine/methionine Type 1 ...

Elimination of redundant synapses and strengthening of the surviving ones are crucial steps in the development of the nervous system. Both processes can be readily followed at the climbing fiber to Purkinje cell synapse in the cerebellum. Shortly after birth, around five equally strong climbing fiber synapses are established. Subsequently, ...

Purkinje fibers in mammalian hearts are known to comprise the following three groups depending on their structure: group I found commonly in ungulates, group II in humans, monkeys and dogs, and group III in rodents. The aim of the present study was to document precisely the cytoarchitecture of a network ...

A recent controversy has emerged concerning the existence of long pauses, presumably reflecting bistability of membrane potential, in the cerebellar Purkinje cells (PC) of awake animals. It is generally agreed that in the anesthetized animals and in vitro, these cells switch between two stable membrane potential states: a depolarized state ...

Glutamate receptor delta 2 (GluRdelta2) is selectively expressed in the cerebellum, exclusively in the spines of the Purkinje cells (PCs) that are in contact with parallel fibers (PFs). Although its structure is similar to ionotropic glutamate receptors, it has no channel function and its ligand is unknown. The GluRdelta2-null mice, ...

BACKGROUND: During development, neurons modify their axon growth mode switching from an elongating phase, in which the main axon stem reaches the target territory through growth cone-driven extension, to an arborising phase, when the terminal arbour is formed to establish synaptic connections. To investigate the relative contribution of cell-autonomous factors ...

Climbing fiber discharges within the rat cerebellar cortex have been shown to display synchrony, especially for climbing fibers terminating in the same parasagittal bands. In addition, Purkinje cells which have the smallest rostrocaudal separation also seem to have the highest degree of synchrony. But this has so far only been ...

The climbing fiber (CF) to Purkinje cell (PC) synapse in the cerebellum provides an ideal model for the study of developmental rearrangements of neural circuits. At birth, each PC is innervated by multiple CFs. These surplus CFs are eliminated during postnatal development, and mono innervation is attained by postnatal day ...

The establishment of neural circuits involves both the precise positioning of cells within brain regions and projection of axons to specific target cells. In the cerebellum (Cb), the medial-lateral (M-L) and anterior-posterior (A-P) position of each Purkinje cell (PC) and the topography of its axon can be defined with respect ...

Επίσης παρουσιάστηκε στο: 111th Annual Meeting of the American Neurological Association, Boston, U.S.A.

We recently produced transgenic mice that expressed an abnormally expanded polyglutamine (polyQ) specifically in cerebellar Purkinje cells (polyQ mice). The polyQ mice showed inclusion body formation, cerebellar atrophy and severe ataxia. Here we analyzed polyQ mice using immunohistochemistry, immunoelectronmicroscopy and electrophysiology. A diffuse form of polyQ was detected in the ...

The delta2 glutamate receptor (GluRdelta2) is predominantly expressed in cerebellar Purkinje cells and plays crucial roles in cerebellar functions: GluRdelta2-null mice display ataxia and impaired motor learning. Interestingly, the contact state of synapses between parallel fibers (PFs) and Purkinje cells is specifically and severely affected, and the number of normal ...

Spinocerebellar ataxia type 14 (SCA14) is an autosomal, dominant neurodegenerative disorder caused by mutations in PKCgamma. The objective of this study was to determine effects of PKCgamma H101Y SCA14 mutation on Purkinje cells in the transgenic mouse. Results demonstrated that wild type PKCgamma-like Purkinje cell localization of HA-tagged PKCgamma H101Y ...

We investigated the expression of 14-3-3 protein and its 7 isoforms during postnatal development of rat cerebellum with immunoblot and immunohistochemistry with isoform-specific antibodies. The relative amounts of total 14-3-3 protein, probed by an antibody (14-3-3 COM) recognizing a sequence shared among its isoforms, exhibited no significant changes from postnatal ...

Essential tremor (ET) is one of the most common neurological diseases. A basic understanding of its neuropathology is now emerging. Aside from Purkinje cell loss, a prominent finding is an abundance of torpedoes (rounded swellings of Purkinje cell axons). Such swellings often result from the mis-accumulation of cell constituents. Identifying ...

During development, Purkinje axons elongate along precise trajectories and acquire stereotypic branching patterns to innervate targets in the deep nuclei and cerebellar cortex. These processes are accomplished through cell-intrinsic mechanisms, whose operation is regulated by environmental signaling cues. Here, we show that Anosmin-1, the protein defective in the X-linked form ...