The distribution of GABA and/or glycine like immunoreactive nerve terminals on the soma of the masseteric gamma motoneurons were investigated using retrograde tracing of WGA-HRP (wheat germ agglutinin conjugated horseradish peroxidase) and postembedding immunogold labeling methods in serial ultrathin sections. Quantitative analysis of 140 nerve terminals apposing on somata of gamma motoneuron size less than 21 mm in average diameter was performed. The results obtained were as follows. 1. Synaptic covering % of apposing nerve terminals was 21.45+/-11.48% and packing density was 12.85+/-6.17. 2. Nerve terminals immunoreactive (IR) to GABA or glycine were F type containing pleomorphic vesicles with round shape predominant. Majority of nerve terminals immunonegative to GABA or glycine were S type containing spherical vesicles and few of them were F type. 3. 11.42+/-10.00% of examined nerve terminals were IR to GABA only, and 12.71+/-9.85% were IR to GABA and glycine, and 15.21+/-9.58% were IR to glycine only. 4. Synaptic covering % of nerve terminals IR to glycine only was highest (4.58+/-4.50%), followed in order by GABA and glycine (3.18+/-2.77%), and GABA only (2.38+/-2.06%). 5. Among all terminals, immunonegative nerve terminals (60.66+/-14.65%) were much more than nerve terminals immunoreactive to GABA and/or glycine (39.34+/-14.65%) These results show that inhibitory synaptic input and synaptic organization of the masseteric gamma motoneurons reveal characteristic features in contrast to that of alpha motoneurons and which may correlated to the electrophysi-ological characteristics of masseteric gamma motoneurons.
Animals ; Armoracia ; Carisoprodol ; gamma-Aminobutyric Acid* ; Glycine* ; Jaw* ; Presynaptic Terminals* ; Rats* ; Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate

Little is known about processing mechanism of sensory input from the periodontal ligaments to the trigeminal motor nucleus for the control of chewing force and modulation of chewing pattern. Low threshold mechanoreceptive periodontal afferent was labeled with horseradish peroxidase by use of intra-axonal injection technique and investigated with electron microscopy. Quantitative ultrastructural analysis was performed on the 39 serially reconstructed labeled boutons in the trigeminal motor nucleus in cat. Labeled bouton contained clear spherical vesicles and one or two large dense cored vesicles. Most of labeled boutons were dome or round shape. All the analysed labeled boutons were presynaptic to dendritic shaft or distal dendrite and those presynaptic to soma or proximal dendrite were not observed. A large number of labeled boutons (46.2%) were postsynaptic to one or two presynaptic pleomorphic vesicle containing endings. Synaptic triad, in that a presynaptic ending which is presynaptic to the labeled bouton, in turn, is presynaptic to dendrite that is postsynaptic to the labeled bouton, was observed in 10.3% of the labeled boutons. Most of the labeled boutons showed simple synaptic organization, in that 64.1% of the labeled boutons made synaptic contacts with one or two neuronal profiles. One (2.6%) of the 39 analyzed labeled boutons showed synaptic contacts with 5 or more neuronal profiles. Labeled bouton volume, mitochondrial volume, apposed surface area and active zone area showed wide variation. These ultrastructural parameters were positively correlated with bouton volume. The values for apposed surface area and active zone area with presynaptic p-endings, in contrast to those with postsynaptic dendrites, showed narrow range and had little correlation with bouton volume. The present study revealed characteristic features on ultrastructural parameters of labeled boutons from periodontal afferent which is involved in periodontal masseteric reflex, and that influence on the postsynaptic trigeminal motoneurons showed wide variability.
Animals ; Carisoprodol ; Cats ; Dendrites ; Horseradish Peroxidase ; Mastication ; Microscopy, Electron ; Mitochondrial Size ; Neurons ; Periodontal Ligament ; Reflex ; Synapses

We examined the hypothesis that mild hypothermia (rectal temperature 34 degrees C) results in the same survival time, whether induced spontaneously or intentionally, during untreated, lethal, uncontrolled hemorrhagic shock in rats. Sixty-four Sprague-Dawley male rats were randomly assigned to normothermia (Nth) (n=19), spontaneous mild hypothermia (Sp.Hth) (n=25) or controlled mild hypothermia (Con.Hth) (n=20) groups. After blood withdrawal of 3 mL/100 g over 15 minutes, followed by 75% tail amputation under spontaneous breathing and light anesthesia by i.p. injection of pentobarbital sodium, rats were observed without fluid resuscitation or hemostasis for 180 minutes or until death. The initial temperature of the Nth group was artificially maintained throughout the experiment. For the mild hypothermia groups, the Sp.Hth group was exposed to ambient temperature while the Con. Hth group was actively cooled to a target rectal temperature of 34 degrees C. In the Con.Hth group, all rats except one died before 180 minutes. All rats in the Nth group died within 38 minutes, and within 67 minutes in the Sp.Hth group. The average survival time was shortest in the Nth group at 20.3 +/- 5.3 minutes, followed by the Sp.Hth group at 30.1 +/- 13.5 minutes, and the Con.Hth group at 81.9 +/- 39.8 minutes (p 0.01). Tail bleed out volume was 0.51 +/- 0.19, 0.26 +/- 0.15 and 0.19 +/- 0.12 mL/100 g in the Nth, Sp.Hth and Con.Hth groups, respectively (p 0.05). In conclusion, spontaneous mild hypothermia did not prolong the survival time as much as controlled mild hypothermia in the rat model for untreated, lethal, uncontrolled hemorrhagic shock.
Animal ; Blood Pressure ; Body Temperature ; Hypothermia/*physiopathology ; *Hypothermia, Induced ; Male ; Rats ; Rats, Sprague-Dawley ; Shock, Hemorrhagic/*mortality/physiopathology/therapy

Previous studies have shown that inhibitory synaptic inputs are different between in spinal and trigeminal motor systems and activities of jaw closing and opening alpha motoneurons are different during a chewing cycle. This study examined the distribution of inhibitory synapses made on masseter and digastric motoneurons by using retrograde tracing of wheat germ agglutinin conjugated to horseradish peroxides (WGA-HRP) combined with postembedding immunogold labeling on serial ultrathin sections.Many boutons IR (immunoreactive) to GABA and/or glycine were found to appose on two kinds of motoneurons, which were containing pleomorphic vesicles (a mixture of round, oval and flattened vesicles) and exhibited symmetrical synaptic contacts on the somata. Packing density and synaptic covering % were higher in digastric than in masseter motoneurons. Of 703 boutons apposing on 12 masseter motoneurons, 6.08+/-3.51, 29.67+/-8.89 and 17.78+/-5.22% were IR to GABA only, glycine only, and both GABA and glycine, respectively. Of 637 boutons apposing on 11 digastric motoneurons, 6.37+/-4.64, 19.74+/-8.25 and 12.01+/-5.38% were IR to GABA only, glycine only, and both GABA and glycine, respectively. Proportions of glycine IR boutons were higher than that of GABA IR boutons in both masseter and digastric motoneurons. Packing density and proportion of boutons IR to GABA and/or glycine were higher in jaw closing than in jaw opening motoneurons (packing density, 12.03+/-1.58 vs 10.28+/-2.99; proportion of IR boutons, 53.54+/-8.94% vs 38.12+/-9.38% in jaw closing and opening motoneurons, respectively). These results provide ultrastructural evidence that GABA and glycine act as important neurotransmitters for modulation of jaw movement and that proportion of inhibitory synapses is higher in jaw closing than in jaw opening motoneurons.
Animals ; Armoracia ; gamma-Aminobutyric Acid ; Glycine ; Jaw ; Mastication ; Neurotransmitter Agents ; Peroxides ; Rats* ; Synapses ; Triticum ; Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate

PURPOSE: In patients with independent mobility, full hip range of motion and sufficient muscle strength for daily life without cognitive impairment, treatment of a femoral neck fracture with total hip arthroplasty (THA) may be a better option compared to bipolar hip hemiarthroplasty. Here, functional outcomes and complications in patients who underwent THA for femoral neck fracture based on their comorbidity status were analyzed. MATERIALS AND METHODS: Between January 2013 and December 2018, 110 patients were treated with THA for femoral neck fractures at our institution. These patients were retrospectively analyzed for clinical outcomes at final follow-up (mean=24.4 months, range: 6–81 months) using the Harris hip score (HHS) and the presence or absence of two potential comorbidities: i) diabetes mellitus (DM; 35 with and 75 without) and ii) hypertension (HTN; 50 with and 60 without). RESULTS: The incidence of superficial infections at the surgical site in patients with DM was significantly higher compared with patients without DM (P=0.024). There were no significant differences in other potential complications based on DM status. HHS at final follow-up between patients with and without DM and with and without HTN were not significantly different (83.3 vs. 81.0, P=0.39 and 81.6 vs. 82.4, P=0.75, respectively). CONCLUSION: Superficial infections occurred more frequently in patients with DM compared with patients without DM. DM and HTN status are not correlated with HHS.
Arthroplasty, Replacement, Hip ; Cognition Disorders ; Comorbidity ; Diabetes Mellitus ; Femoral Neck Fractures ; Femur Neck ; Follow-Up Studies ; Hemiarthroplasty ; Hip ; Humans ; Hypertension ; Incidence ; Muscle Strength ; Range of Motion, Articular ; Retrospective Studies

The purpose of this study was to investigate any relationship between the geometric factors of synaptic contacts of muscle spindle afferent terminals and masseteric motor neurons in the trigeminal motor nucleus. Terminals from the masseteric muscle spindle afferents were stained with intra-axonal injection of HRP and were examined electronmi-croscopically with serial sections at the central and peripheral regions of trigeminal motor nucleus of the cat. The number of terminals examined were 76 in peripheral and 105 in central region. The results obtained were as follows. 1. Most of the labeled terminals showed simple synaptic connectivity. Each terminals in peripheral and central region made synaptic contact with 1 to 5 neuronal profiles. Two or three labeled terminals were occasionally seen to make synaptic contact with the same dendrite. 2. The average number of postsynaptic proximal dendrite per labeled terminal was higher in the central region than in the peripheral region. In contrast, that of postsynaptic distal dendrite per labeled terminal was higher in the peripheral region than in the central region. 3. The average diameter of postsynaptic dendrites in the central region was larger than that in the peripheral region. This imply terminals in the peripheral region contacted with further distal part of the distal dendrite than that in the central region. These results indicate that synaptic connectivity associated with the spindle afferents from masseteric muscle is different according to their geometric location within the trigeminal motor nucleus and suggest that there will be precise interrelationship between the morphology, pattern of synaptic connectivity and functions of muscle spindle afferents.
Animals ; Cats* ; Dendrites ; Motor Neurons ; Muscle Spindles* ; Neurons

To analyze the synaptic characteristics of axon terminals originated from tooth pulp in the trigeminal principal sensory nucleus, and find morphological evidence that p-endings on these terminals use GABA as neurotransmitter, labeling of tooth pulp afferents with wheat -germ agglutinin conjugated horseradish peroxidase, postembedding immunocytochemistry and morphometric analysis were performed. The results obtained were as follows. The labeled boutons contained clear and round synaptic vesicles, and the mean number of synaptic contacts was 4.21 +/- 2.58. The postsynaptic profiles were usually middle or distal dendrites and dendritic spines rather than soma or proximal dendrites. The mean number of synaptic contacts with p -endings was 2.62 +/- 2.01. The volume of labeled bouton was 4.39 +/- 3.08 micro meter 3 and highly correlated (P<.01) with surface area (r = 0.96), total apposed surface area (r = 0.84), total active zone area (r = 0.84), mitochondrial volume (r = 0.95), the number of synaptic vesicles (r = 0.92), the number of synaptic profiles (r = 0.76) and the number of synaptic p -endings (r = 0.67). The p -endings contained pleomorphic synaptic vesicles. The volume of p -ending was 0.91 +/- 0.47 micro meter 3 and highly correlated (P<.01) with surface area (r = 0.94), total apposed surface area (r = 0.76), total active zone area (r = 0.62), mitochondrial volume (r = 0.70) and the number of synaptic vesicles (r = 0.94). P -endings were GABA immunoreactive. These results suggest that tooth pulp afferent terminals in trigeminal principal sensory nucleus may be related to complex processing of sensory information and presynaptic p -endings using GABA as neurotransmitter, are important in this sensory processing. The "size principle" of Pierce and Mendel (1993) is also applicable to tooth pulp afferent terminals and presynaptic p -endings.
Carisoprodol ; Dendrites ; Dendritic Spines ; gamma-Aminobutyric Acid ; Horseradish Peroxidase ; Immunohistochemistry ; Mitochondrial Size ; Neurotransmitter Agents ; Presynaptic Terminals ; Synaptic Vesicles ; Tooth* ; Triticum

Midpalatal suture expansion if often used for patients having narrow maxillary arch, cleft palate, respiratory handicap with narrow nasal cavity. CGRP has been known as a modulator of pain transmission in central nervous system and a local effector to peripheral tissue causing vasodilation, increase of blood flow, modulation of immunesystem, regulation of macrophagic function and stimulation of bone formation. To investigate changes of CGRP-immunoreactive nerve fibers in midpalatal suture during the expansion, immunohistochemical study was performed by using rats. Experimental rats (10 weeks, 250 gm) were divided into five groups (control, 1, 4, 7, 14 days group (each n=4) and applied orthodontic force (approximately 200gm) to upper anterior incisors. Frozen sections of midpalatal suture area were immunostained by using rabbit antisera. The results were as follows: The CGRP-immunoreactive nerve fibers were hardly observed in control group. In 1 day group, the CGRP-immunoreactive nerve fibers were more increased around the vessels than control group. In 4 days group, the CGRP-immunoreactive nerve fibers were more increased than control group, but nor more increased than 1 day group. Vascular diameter was more enlarged. In 7 days group, especially, hematoxilin affinity of cells was remarkable and cells were arranged along the bone margin. The CGRP-immunoreactive nerve fibers were more reduced than 4 days group and vascular diameter was also reduced. In 14 days group. the CGRP-immunoreactive nerve fibers were similar to those of 7 days group and the irregularity of bone margin was almost recoverd. In Conclusion, the CGRP-immunoreactive nerve fibers may be related to intial neurogenic inflammatory reaction in expanding mid-palatal suture.
Animals ; Central Nervous System ; Cleft Palate ; Frozen Sections ; Humans ; Immune Sera ; Incisor ; Nasal Cavity ; Nerve Fibers* ; Osteogenesis ; Rats* ; Sutures* ; Vasodilation

The purpose of this study is to investigate the cross -sectional anatomy of posterior mandibular body for proper determination of bucco -lingual implant path. Using fifty -four human mandibles, negative images of each mandible were made of agar impression material. The agar blocks were cut through the imaginary long axis of each root of three molars (M1M, M1D, M2M, M2D and M3). The depth of submandibular fossa, the angulation of long axis of mandibular body and tooth, and the length, angulation and ratio of alveolar bone superior to mylohyoid ridge and basal bone inferior to mylohyoid ridge were measured. The results obtained were as follows; 1. All of the measured angulations were decreased as it moves from M1M to M3. 2. The correlation coefficients among the angulation of the mandibular bone and the crown axis showed the high relationship (r=0.793), and the crown axis was steeper than the mandibular bone axis by 6.2 at M1M and 7.6 at M2M. 3. The length of upper alveolar bone was decreased, but that of inferior basal bone was increased as it moves from M1M to M3. 4. The depth of submandibular fossa was increased as it moves from M1M to M3. These results indicate that the angulation of implant path at the posterior mandible must be tilted more than wax -up crown axis by 6.2 at mesial root of 1st molar and by 7.6 at mesial root 2nd molar area for prevention of lingual cortical bone perforation during implant surgery.
Agar ; Axis, Cervical Vertebra ; Crowns ; Humans ; Mandible* ; Molar ; Tooth

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