Disturbances in vestibular functions caused by unilateral labyrinthectomy (UL) are spontaneously ... more Disturbances in vestibular functions caused by unilateral labyrinthectomy (UL) are spontaneously restored during the process of vestibular compensation due to the plasticity of CNS. The underlying molecular background of vestibular compensation is not yet fully understood. Recent studies have shown that the extracellular matrix (ECM) molecules have either permissive or non-permissive effect on the neural plasticity. In our previous study we have demonstrated changes in the expression of hyaluronan (HA) in the vestibular nuclei (VN) of the frog following peripheral vestibular lesion. The present work was undertaken to examine the expression of the HA and chondroitin sulfate proteoglycans (CSPGs) in the lateral vestibular nucleus (LVN) of the rat following UL by using histochemical methods. On the first postoperative day, the condensation of the ECM around the neurons, the perineuronal net (PNN) was not distinguished from the surrounding neuropil on the side of UL indicating the desorganization of its molecular structure. At survival day 3, the PNN was recognizable with the HA probe, whereas its staining for the CSPGs was restored by the time of the seventh postoperative day. In the neuropil, the intensity of the HA increased on the operated side, while the CSPGs reaction almost completely disappeared. The present study have demonstrated for the first time that the UL is accompanied by the modification of the HA, and CSPG staining pattern in the PNN of the LVN in the rat. As the reorganization of the PNN corresponds to the restoration of spontaneous activity of vestibular neurons, our study implies the role of HA and CSPGs in the vestibular compensation.
Previous studies have demonstrated that the molecular and structural composition of the extracell... more Previous studies have demonstrated that the molecular and structural composition of the extracellular matrix (ECM) shows regional differences in the central nervous system. By using histochemical and immunohistochemical methods, we provide here a detailed map of the distribution of ECM molecules in the vestibular nuclear complex (VNC) of the rat. We have observed common characteristics of the ECM staining pattern in the VNC and a number of differences among the individual vestibular nuclei and their subdivisions. The perineuronal net (PNN), which is the pericellular condensation of ECM, showed the most intense staining for hyaluronan, aggrecan, brevican and tenascin-R in the superior, lateral and medial vestibular nuclei, whereas the HAPLN1 link protein and the neurocan exhibited moderate staining intensity. The rostral part of the descending vestibular nucleus (DVN) presented a similar staining pattern in the PNN, with the exception of brevican, which was negative. The caudal part of the DVN had the weakest staining for all ECM molecules in the PNN. Throughout the VNC, versican staining in the PNN, when present, was distinctive due to its punctuate appearance. The neuropil also exhibited heterogeneity among the individual vestibular nuclei in ECM staining pattern and intensity. We find that the heterogeneous distribution of ECM molecules is associated in many cases with the variable cytoarchitecture and hodological organization of the vestibular nuclei, and propose that differences in the ECM composition may be related to specific neuronal functions associated with gaze and posture control and vestibular compensation.
The prepositus hypoglossi nucleus (PHN) is a mossy fiber-generating precerebellar nucleus of the ... more The prepositus hypoglossi nucleus (PHN) is a mossy fiber-generating precerebellar nucleus of the brainstem, regarded as one of the neural integrators of the vestibulo-ocular reflex. The aim of the present work is to reveal the distribution of various molecular components of the extracellular matrix (ECM) in the prepositus hypoglossi nucleus by using histochemical and immunohistochemical methods. Our most characteristic finding was the accumulation of the ECM as perineuronal net (PNN) and axonal coat and we detected conspicuous differences between the magnocellular (PHNm) and parvocellular (PHNp) divisions of the PHN. PNNs were well developed in the PHNm, whereas the pericellular positivity was almost absent in the PHNp, here a diffuse ECM was observed. In the PHNm the perineuronal net explored the most intense staining with the aggrecan, and tenascin-R antibodies followed by the hyaluronan, then least with reactions for chondroitin sulfate-based proteoglycan components and HAPLN1 li...
Disturbances in vestibular functions caused by unilateral labyrinthectomy (UL) are spontaneously ... more Disturbances in vestibular functions caused by unilateral labyrinthectomy (UL) are spontaneously restored during the process of vestibular compensation due to the plasticity of CNS. The underlying molecular background of vestibular compensation is not yet fully understood. Recent studies have shown that the extracellular matrix (ECM) molecules have either permissive or non-permissive effect on the neural plasticity. In our previous study we have demonstrated changes in the expression of hyaluronan (HA) in the vestibular nuclei (VN) of the frog following peripheral vestibular lesion. The present work was undertaken to examine the expression of the HA and chondroitin sulfate proteoglycans (CSPGs) in the lateral vestibular nucleus (LVN) of the rat following UL by using histochemical methods. On the first postoperative day, the condensation of the ECM around the neurons, the perineuronal net (PNN) was not distinguished from the surrounding neuropil on the side of UL indicating the desorganization of its molecular structure. At survival day 3, the PNN was recognizable with the HA probe, whereas its staining for the CSPGs was restored by the time of the seventh postoperative day. In the neuropil, the intensity of the HA increased on the operated side, while the CSPGs reaction almost completely disappeared. The present study have demonstrated for the first time that the UL is accompanied by the modification of the HA, and CSPG staining pattern in the PNN of the LVN in the rat. As the reorganization of the PNN corresponds to the restoration of spontaneous activity of vestibular neurons, our study implies the role of HA and CSPGs in the vestibular compensation.
Previous studies have demonstrated that the molecular and structural composition of the extracell... more Previous studies have demonstrated that the molecular and structural composition of the extracellular matrix (ECM) shows regional differences in the central nervous system. By using histochemical and immunohistochemical methods, we provide here a detailed map of the distribution of ECM molecules in the vestibular nuclear complex (VNC) of the rat. We have observed common characteristics of the ECM staining pattern in the VNC and a number of differences among the individual vestibular nuclei and their subdivisions. The perineuronal net (PNN), which is the pericellular condensation of ECM, showed the most intense staining for hyaluronan, aggrecan, brevican and tenascin-R in the superior, lateral and medial vestibular nuclei, whereas the HAPLN1 link protein and the neurocan exhibited moderate staining intensity. The rostral part of the descending vestibular nucleus (DVN) presented a similar staining pattern in the PNN, with the exception of brevican, which was negative. The caudal part of the DVN had the weakest staining for all ECM molecules in the PNN. Throughout the VNC, versican staining in the PNN, when present, was distinctive due to its punctuate appearance. The neuropil also exhibited heterogeneity among the individual vestibular nuclei in ECM staining pattern and intensity. We find that the heterogeneous distribution of ECM molecules is associated in many cases with the variable cytoarchitecture and hodological organization of the vestibular nuclei, and propose that differences in the ECM composition may be related to specific neuronal functions associated with gaze and posture control and vestibular compensation.
The prepositus hypoglossi nucleus (PHN) is a mossy fiber-generating precerebellar nucleus of the ... more The prepositus hypoglossi nucleus (PHN) is a mossy fiber-generating precerebellar nucleus of the brainstem, regarded as one of the neural integrators of the vestibulo-ocular reflex. The aim of the present work is to reveal the distribution of various molecular components of the extracellular matrix (ECM) in the prepositus hypoglossi nucleus by using histochemical and immunohistochemical methods. Our most characteristic finding was the accumulation of the ECM as perineuronal net (PNN) and axonal coat and we detected conspicuous differences between the magnocellular (PHNm) and parvocellular (PHNp) divisions of the PHN. PNNs were well developed in the PHNm, whereas the pericellular positivity was almost absent in the PHNp, here a diffuse ECM was observed. In the PHNm the perineuronal net explored the most intense staining with the aggrecan, and tenascin-R antibodies followed by the hyaluronan, then least with reactions for chondroitin sulfate-based proteoglycan components and HAPLN1 li...
Uploads