Masahiro Kawamoto

Fos induction in the amygdala by vestibular information during hypergravity stimulation

Altered gravity environments including both hypo- and hypergravity can elicit motion sickness. Vestibular information is known to be essential for motion sickness, but its other neural substrates are poorly understood. We previously showed that bilateral lesions of the amygdala suppressed hypergravity-induced motion sickness in rats, using pica behavior as an emetic index. We show in the present study that during hypergravity stimulation, vestibular information activated the central nucleus of the amygdala (CeA), as determined by the induction of Fos expression, in comparison between normal and bilaterally labyrinthectomized rats. The finding that Fos expression was confined to the CeA and almost completely absent in other subnuclei of the amygdala contrasted with many previous studies that used other stressful stimuli such as foot shock, restraint and forced swimming, suggesting a specific vestibular effects on the amygdala. Prolongation of hypergravity resulted in reduction of Fos expression in the CeA, suggesting a process of habituation. Such decreases appeared earlier than in the vestibular nucleus, suggesting that adaptive changes in the CeA to hypergravity were independent of changes in the vestibular input. Our results suggest the amygdala is a neural substrate involved in the development of and habituation to motion sickness.

Effects of cooling the pharyngeal mucosa after bipolar scissors tonsillectomy on postoperative pain

Abstract Conclusion: Bipolar scissors tonsillectomy followed by cooling down the pharyngeal mucosa has advantages in terms of postoperative pain and intraoperative blood loss compared with cold dissection. Objectives: The purpose of this study was to compare the postoperative pain between bipolar scissors tonsillectomy followed by cooling the pharyngeal mucosa and a traditional cold dissection. Methods: A total of 189 patients aged more than 16 years were operated due to habitual tonsillitis, obstructive sleep apnea syndrome, and IgA nephropathy. Of these, 79 patients were operated using bipolar scissors followed by cooling the pharyngeal mucosa with 4°C saline for 10 min just after the removal of tonsils. The other 110 patients underwent cold dissection tonsillectomy. Outcome measures were intraoperative blood loss, operative time, postoperative pain evaluated on a visual analog scale, and postoperative secondary hemorrhage. Results: Significantly lower levels of intraoperative blood loss and less postoperative pain were obtained in bipolar scissors tonsillectomy followed by cooling the pharyngeal mucosa compared with cold dissection. Postoperative hemorrhage needing hemostatic surgery occurred in 2 of 79 patients who underwent bipolar scissors tonsillectomy with cooling, while it occurred in 1 of 110 patients after cold dissection. However, the difference was not statistically significant.

Evaluation of the T&T Olfactometer by Mapping c-fos Protein in an Olfactory Bulb

Objectives: Although in Japan the T&T olfactometer is most commonly used in patients suffering from smelling disorders, no scientific analysis has been performed so far. The objective of this study was to clarify whether the five odorants used in the T&T olfactometer are suitable or not. We mapped the glomeruli activated by the five test odorants employed in the T&T olfactometer. The expression of c-fos protein as a marker of neuronal excitation was monitored using an immunohistochemical technique. Study Design: The expression of c-fos protein in the rat olfactory bulb was investigated to determine what part of the olfactory system is activated by five odorants used in the T&T olfactometer. Methods: Each rat was isolated in a clean cage for 120 min to reduce the basal expression of c-fos protein. Each rat was fixed in the cage and exposed to one of five test odorants for 90 min. The expression of c-fos protein was measured using an immunohistochemical technique. Results: Each odorant activated numerous glomeruli and the patterns of distribution of activated glomeruli were specific to each odorant. Glomeruli in most regions of the bulb were activated by all five test odorants. Conclusion: We assume that in the T&T olfactometer the optimal ((five)) odorants are employed, because the glomeruli activated by those odorants showed unique patterns in the immunohistochemical assay.

Developmental changes in GABA transporter (GAT1 and GAT3) mRNA expressions in the rat olfactory bulb

Developmental expressions of GABA transporters 1 and 3 (GAT1 and GAT3) were investigated in the rat olfactory bulb by using in situ hybridization histochemistry. We found that the expression of GAT1 and GAT3 mRNAs was dramatically changed in the granule cell layer (GCL), external plexiform layer (EPL) and glomerular layer (GL) during postnatal development. Among bulbar neurons, granule cells and periglomerular cells are GABAergic and they are localized in the GCL and GL, respectively. In the EPL, granule cells make GABAergic synapses with mitral cell dendrites. Thus, the changes seen in the GCL, EPL and GL seemed related to the development of the GABAergic system in the olfactory bulb. On the whole, our results demonstrated that expression patterns of GAT1 and GAT3 mRNAs have become similar to adult patterns on postnatal day 14 (P14), suggesting that GABA transporters may play a pivotal role in GABAergic neurotransmission after P14. However, expression patterns of GAT1 and GAT3 mRNAs in early postnatal days were quite distinct from those in adulthood. For example, in the GCL, immature granule cells already exhibited strong levels of GAT1 mRNA on P1 and the expression level was higher than that of granule cells in adulthood. GAT3 mRNA was strongly expressed in presumable radial glial cells surrounding the subependymal layer. In the EPL, few signals for the two transcripts were detected on P1 but they were markedly increased by P14. Our results indicate that GAT1 and GAT3 may play important roles in the development of the GABAergic system in the olfactory bulb.

Modulation of T-cell Functions by Laser Surgery in Patients with Allergic Rhinitis

Objective—Potassium-titanyl-phosphate (KTP) laser turbinectomy is an established treatment for hypertrophied inferior turbinates that do not respond to other medical treatments. KTP laser surgery is usually performed with the aim of reducing the size of hypertrophied inferior turbinates. We hypothesized that laser vaporation may also inhibit the allergic reaction in the nasal mucosa of inferior turbinates. Material and Methods—We examined the effect of KTP laser therapy on T-cell responses using peripheral blood mononuclear cells (PBMCs). Results—Levels of T-cell proliferation after stimulation with Staphylococcus enterotoxin B (SEB) were higher in post- than pre-surgery patients. Levels of interferon-gamma and IL-2 produced by PBMCs after stimulation with SEB appeared to be higher in post- than pre-surgery patients. Serum levels of house dust-specific IgE were lower in post- than pre-surgery patients. These results indicate that KTP laser therapy modulates T-cell responses and probably tilts the Th1/Th2 ...Objective—Potassium-titanyl-phosphate (KTP) laser turbinectomy is an established treatment for hypertrophied inferior turbinates that do not respond to other medical treatments. KTP laser surgery is usually performed with the aim of reducing the size of hypertrophied inferior turbinates. We hypothesized that laser vaporation may also inhibit the allergic reaction in the nasal mucosa of inferior turbinates. Material and Methods—We examined the effect of KTP laser therapy on T-cell responses using peripheral blood mononuclear cells (PBMCs). Results—Levels of T-cell proliferation after stimulation with Staphylococcus enterotoxin B (SEB) were higher in post- than pre-surgery patients. Levels of interferon-gamma and IL-2 produced by PBMCs after stimulation with SEB appeared to be higher in post- than pre-surgery patients. Serum levels of house dust-specific IgE were lower in post- than pre-surgery patients. These results indicate that KTP laser therapy modulates T-cell responses and probably tilts the Th1/Th2 balance towards the Th1-dominant state. Conclusions—KTP laser surgery eases or cures allergic rhinitis not only by reducing the volume of the inferior turbinates but also by modulating T-cell functions.

The alteration of odor-induced c-Fos immunoreactivity in the rat olfactory bulb after olfactory nerve transection.

Abstract. We used the rats in which one olfactory nerve had been transected and observed the odor (Propionic acid) -induced c-Fos immunoreactivity in the bulb at different times (2, 4, 8 weeks) after nerve transection. The exposure to odor produced a strong cluster of c-Fos positive cells in the mediodorsal region of the intact bulb. On the other hand, the transected bulb showed much less reactivity 2 weeks after neurectomy; however, a large number of positive cells were observed in the whole of the bulb from 4 weeks after neurectomy. Furthermore, we measured the levels of mRNA for tyrosine hydroxylase (TH), which was the marker of odor-induced olfactory nerve activity in the bulb, by using real-time PCR. The level of TH mRNA decreased on the transected side at 2 weeks but recovered to the level of the contralateral side at 4 weeks after neurectomy. We firstly demonstrated that projection mapping of odor receptors was altered after olfactory nerve transection by using an immunohistochemical method.

Power-Assisted Partial Adenoidectomy (PAPA) with Total Tonsillectomy for Pediatric Obstructive Sleep Apnea Syndrome

Obstructive sleep apnea syndrome (OSAS) in youth causes various sequelae—life-threatening, body composition and school performance. Adenotonsillar surgery is beneficial for treating pediatric OSAS, however, the traditional methods pose some problems such as re-multiplication of adenoids. We performed total tonsillectomy and Power-Assisted Partial Adenoidectomy (PAPA) in 111 children for 3 years and 25 cases were examined Oxygen Desaturation Index 3% (ODI 3%) during sleep with a pulseoxymeter before and after the operation.Their ODI 3% improved significantly after surgery. No long-term complications, such as relapse of OSAS and immunodeficiency, have occurred. PAPA with total tonsillectomy is very useful for the treatment of pediatric OSAS.

A simple method of cranial tracking for conscious patients and its application to computer-assisted endoscopic sinus surgery under local anesthesia

Abstract In this work, our aim was to develop a cranial tracking method for conscious patients that can be used without any intervention or pain to the patient, yet with acceptable accuracy in computer-assisted endoscopic sinus surgery under local anesthesia. In the method, active or passive markers are simply attached to the facial skin to track the patients head. In this paper, we clarified the criteria for various parameter setting so that this simple method effectively works. In our experiments, we demonstrated that high level of accuracy and usability are attainable by giving careful consideration to the selection of areas on the facial skin for marker attachment and acquisition of the marker configuration in the expressionless condition.