Trochlear motorneurons were identified by applying horseradish peroxidase(HRP) to superior oblique muscle in cats. Ninety five to ninety seven percent of the contralateral trochlear nucleus were stained 3-5% of ipsilateral side also labelled by HRP. These findings showed that superior oblique muscle was innervated by trochlear nuclei on both side.
Animals ; Armoracia* ; Cats* ; Horseradish Peroxidase* ; Trochlear Nerve

No Abstract Available.
Animals ; Armoracia* ; Cats* ; Horseradish Peroxidase* ; Muscles*

To analyze the developmental changes in soma diameters of digastric motoneurons, wheat-germ agglutinin conjugated horseradish peroxidase (WGA-HRP) was injected into the digastric muscle and visualized the retrogradely HRP-labeled motoneurons through tungstate/tetramethylbenzidine (TMB) and following diaminobenzidine (DAB) reactions. The results obtained from Sprague-Dawley rats at postnatal days 1 (P1), 10 (P10) and 30 (P30) indicated as follows: firstly, soma diameters of digastric motoneurons showed unimodal distribution in all postnatal days examined; secondly, the period of P1 to P10 (period 1) showed about 2 times faster growth rate than that of P10 to P30 (period 2); thirdly, the smallest soma examined in each postnatal day exhibited slower growth rate with that of the largest one (increase ratio in soma diameters from P1 to P30, smallest vs. largest =1.62 : 1.93); Finally, relative growth rates a day showed again that period 1 had faster growth rate than that of period 2. Consequently, developmental changes in soma diameters of digastric motoneurons resulted in very different growth rates between both periods. This implies that the growth of the soma is almost completing within P10 and thereafter growing slowly. The period 1 and 2 are corresponding to sucking and sucking/masticatory period, respectively. Therefore present study providing morphological changes in soma diameters of digastric motoneurons suggests that both periods and their different growth rates of the motoneurons in each period may closely be related with each other.
Animals ; Carisoprodol* ; Horseradish Peroxidase ; Rats* ; Rats, Sprague-Dawley

The ultrastructural parameters related to synaptic release of endings which are presynaptic to tooth pulp afferent terminals (p-endings) were analyzed to understand the underlying mechanism for presynaptic modulation of tooth pulp afferents. Tooth pulp afferents were labelled by applying wheat-germ agglutinin conjugated horseradish peroxidase to the rat right lower incisor, whereafter electron microscopic morphometric analysis with serial section and reconstruction of p-endings in the trigeminal oral nucleus was performed. The results obtained from 15 p-endings presynaptic to 11 labeled tooth pulp afferent terminals were as follows. P-endings contained pleomorphic vesicles and made symmetrical synaptic contacts with labeled terminals. The p-endings showed small synaptic release-related ultrastructural parameters: volume, 0.82 ± 0.45 µm³ (mean ± SD); surface area, 4.50 ± 1.76 µm²; mitochondrial volume, 0.15 ± 0.07 µm³; total apposed surface area, 0.69 ± 0.24 µm²; active zone area, 0.10 ± 0.04 µm²; total vesicle number, 1045 ± 668.86; and vesicle density, 1677 ± 684/µm². The volume of the p-endings showed strong positive correlation with the following parameters: surface area (r=0.97, P<0.01), mitochondrial volume (r=0.56, P<0.05), and total vesicle number (r=0.73, P<0.05). However, the volume of p-endings did not positively correlate or was very weakly correlated with the apposed surface area (r=-0.12, P=0.675) and active zone area (r=0.46, P=0.084). These results show that some synaptic release-related ultrastructural parameters of p-endings on the tooth pulp afferent terminals follow the "size principle" of Pierce and Mendell (1993) in the trigeminal nucleus oralis, but other parameters do not. Our findings may demonstrate a characteristic feature of synaptic release associated with p-endings.
Animals ; Horseradish Peroxidase ; Incisor ; Mitochondrial Size ; Rats ; Tooth* ; Trigeminal Nuclei

Keeping an enzyme in its native form with high catalytic activity is of great significance. In the present study, thermal stabilizers of horseradish peroxidase (HRP) were screened. The results indicated that thermal stability of HRP was enhanced by magnesium sulphate and gelatin. A synergic effect of magnesium sulphate and gelatin was observed. In the presence of the stabilizer, the enzymatic activity of HRP remained 89% after kept for 80 h at 50 degrees C and 57% for 90 days at room temperature. Thermal alterations of HRP structure in the absence and presence of the stabilizers were explored by using UV absorption spectra at 402 nm (Soret band), intrinsic fluorescence and 8-anilinonaphthalene-1-sulfonic acid (ANS) fluorescence. The results suggested that magnesium sulphate and gelatin attenuated the extent of unfolding of HRP and therefore the native enzyme structure was stabilized.
Drug Synergism ; Enzyme Stability ; drug effects ; Gelatin ; pharmacology ; Horseradish Peroxidase ; metabolism ; Hot Temperature ; Magnesium Sulfate ; pharmacology

BACKGROUND/AIMS: Although mucosal mast cell tryptase is known to significantly increase intestinal permeability, the relationship between mucosal mast cells and intestinal permeability remains unclear. The objective of this study was to evaluate the correlation among intestinal permeability, tryptase activity and mucosal mast cell count. METHODS: Rectal biopsies from 16 patients with diarrhea-predominant irritable bowel syndrome (IBS-D) and 7 normal subjects were assessed for tryptase activity and macromolecular permeability using horseradish peroxidase in Ussing chambers. In addition, mucosal mast cell levels were immunohistochemically quantified via image analysis. RESULTS: Rectal biopsy of tissues from IBS-D patients showed significantly increased permeability compared with those from normal controls (0.644 +/- 0.08 and 0.06 +/- 0.00 ng/2 hr/mm2, P < 0.01). Tryptase activity was also substantially higher in rectal biopsy samples from IBS-D patients than those from normal controls (0.86 +/- 0.18 and 0.28 +/- 0.04 mU/mg protein, P < 0.05). Mucosal mast cell counts were not significantly different between the 2 groups (P > 0.05). However, correlation analysis revealed that only mucosal mast cell count was significantly correlated with intestinal permeability in IBS-D patients (r = 0.558, P < 0.05). CONCLUSIONS: This study demonstrated a positive correlation between the number of mucosal mast cells and intestinal permeability, suggesting that mucosal mast cells play an important role for increased intestinal permeability in patients with IBS-D.
Biopsy ; Diarrhea ; Horseradish Peroxidase ; Humans ; Irritable Bowel Syndrome ; Mast Cells ; Permeability ; Tryptases

Previous studies suggested that myelinated axons innervating rat molar pulps undergo morphological changes in their peripheral course. However, little information is available on the morphological feature of the parent axons at the site of origin. We therefore investigated the size of the myelinated parent axons and their morphological features at the proximal sensory root of the trigeminal ganglion by horseradish peroxidase (HRP) injection into rat upper molar pulps and subsequent light and electron microscopy. A total of 248 HRP-labeled myelinated axons investigated were highly variable in the size. Fiber area, fiber diameter, axon area (axoplasm area), axon diameter (axoplasm diameter), and myelin thickness were 11.32 +/- 8.36 microm2 (0.80~53.17 microm2), 3.99 +/- 1.53 microm (1.08~9.26 microm), 8.70 +/- 6.30 microm2 (0.70~41.83 microm2), 3.13 +/- 1.13 microm (0.94~7.20 microm) and 0.43 +/- 0.23 microm (0.07~1.06 microm), respectively. The g-ratio (axon diameter / fiber diameter) of the labeled axons was 0.79 +/- 0.05 (0.61~0.91). Axon diameter was highly correlated with myelin thickness (correlation coefficients,r=0.83) but little correlated with g-ratio (r=-0.33) of individual myelinated parent axons. These results indicate that myelin thickness of the myelinated parent axons innervating rat molar pulps increase with increasing axon diameter, thus maintaining a constant g-ratio.
Animals ; Axons* ; Dental Pulp ; Horseradish Peroxidase ; Humans ; Microscopy, Electron ; Molar* ; Myelin Sheath* ; Parents* ; Rats* ; Trigeminal Ganglion*

We investigated the location of neurons related to lateral rectus muscle in the cerebellum of rats. Horseradish peroxidase (HRP) and Pseudorabies virus (PRV) were injected into right lateral rectus muscle of rats. After 84~90 hours, cardiac perfusion was performed with 4% paraformaldehyde in HRP injection group and 4% paraformaldehyde-lysine-periodate in PRV injection group. Tetramethylbenzidine (TMB) neurohistochemical stain in HRP injection group and immuno-histochemical stain in PRV injection group were performed after frozen section. HRP-reactive neuronal cells were observed in ipsilateral abducens nucleus. PRV-immunoreactive neuronal cells were observed ipsilaterally in abducens nucleus, flocculus, paraflocculus, ansiform lobule, declive, dentate nucleus, infracerebellar nucleus and y nucleus and also bilaterally in nodulus, lobulus centralis, lingula, uvula vermis and fastigial nucleus. These findings show the existence of neuronal projection from the abducens nucleus to the cerebellum. This projection could be part of nerve circuits through which the cerebellum modulates visuomotor activities.
Animals ; Cerebellar Nuclei ; Cerebellum* ; Frozen Sections ; Herpesvirus 1, Suid* ; Horseradish Peroxidase ; Neurons* ; Perfusion ; Pseudorabies* ; Rats* ; Uvula

The central projections of the peripheral cochlear nerve fiber from each turn to the cochlear nuclei (CN) in the mongolian gerbil were investigated using retrograde transportation of horseradish peroxidase (HRP). The organ of Corti and the osseous spiral lamina were scratched with an electrolytically-sharpened fine needle via a small hole at each turn of the cochlea. The cochlea was filled with a 30% horseradish peroxidase (HRP) solution. After 48 hours, 50 microns transverse serial sections of the brainstem were made with a vibratome. The tissue was processed with the diaminobenzidine procedure of the cobalt-glucose method. Our experiment revealed that the fibers from the basal turn terminated at the dorsomedial portion of anteroventral cochlear nuclei (AVCN), but those from the apical turn were distributed among the ventrolateral portion of the AVCN. In the posteroventral cochlear nuclei (PVCN) and dorsal cochlear nuclei (DCN), the fibers from basal to apical turns extend from the dorsal to the ventral portion of each nuclei. A distinct tonotopic arrangement could be found between the origin of cochlear fibers of each turn and their termination in the regions of the cochlear nuclei (CN). Also, the results suggested that the scratch method combined with retrograde transportation of horseradish peroxidase was useful in investigating the tonotopic arrangement of the peripheral auditory nerve in the CN.
Animal ; Cochlear Nerve/*anatomy & histology ; Cochlear Nucleus/*anatomy & histology ; Gerbillinae ; Horseradish Peroxidase ; Nerve Fibers

Periodontal-masseteric reflex is implicated in the control of jaw movement and masticatory force during chewing foods. This study is aimed to investigate the synaptic arrangement of mesencephalic periodontal afferents in the trigeminal motor nucleus and to identify the neurotransmitter involved in the presynaptic control of them through the intra-axonal staining of horseradish peroxidase combined with postembedding immunogold methods. Most of the labeled terminals showed synaptic contacts with the small sized dendritic shafts or distal dendrites, while synaptic contacts with the somata or proximal dendrites were not observed. More than one third of the analyzed labeled boutons received presynaptic input from pleomorphic vesicles containing ending (p-ending). About 11% of labeled boutons showed synaptic triads. All the analyzed boutons made synaptic contacts with one to four neuronal profiles and those showing synaptic contact with five or more were not observed. Labeled terminals were larger than presynaptic p-endings. A large number of the analyzed p-endings showed GABA like immunoreactivity. These observations provide evidence that periodontal afferent terminals show very simple and characteristic synaptic arrangements in the trigeminal motor nucleus and that p-endings presynaptic to them may use GABA as a neurotransmitter for presynaptic inhibition.
Animals ; Bite Force ; Dendrites ; gamma-Aminobutyric Acid ; Horseradish Peroxidase ; Jaw ; Mastication ; Neurons ; Neurotransmitter Agents ; Rats* ; Reflex