Fos expression in A1/C1 neurons of rats exposed to hypoxia, hypercapnia, or hypercapnic hypoxia.

The distribution of Fos expression in catecholaminergic neurons with immunoreactivity for dopamine ß-hydroxylase (DBH) of the ventrolateral medulla was compared between rats exposed to hypoxia (10 % O2), hypercapnia (8 % CO2), and hypercapnic hypoxia (8 % CO2 and 10 % O2) for 2 h. Among the experimental groups, hypoxia-exposed rats had more Fos/DBH double-immunoreactive neurons than the control group (20 % O2) in the rostral area of the ventrolateral medulla, specifically in the range of + 150 µm to + 2,400 µm from the caudal end of the facial nerve nucleus. On the other hand, Fos/DBH double-immunoreactive neurons were scarcely observed in the ventrolateral medullary region of hypercapnia-exposed rats. The number of double-immunoreactive neurons in hypercapnic hypoxia-exposed rats was comparable to that in the control group. The present results suggest that adrenergic C1 neurons are specifically activated by hypoxia and are involved in the regulation of respiratory and circulatory functions.

Immunohistochemical distribution of cannabinoid receptor type 1 (CB1) and type 2 (CB2) in the rat carotid body.

The carotid body is a hypoxia-sensitive chemoreceptor that induces sensory long-term facilitation after exposure to chronic intermittent hypoxia. However, the mechanisms underlying synaptic plasticity in the carotid body remain unknown. In the present study, we examined the immunohistochemical distribution of cannabinoid receptor type 1 (CB1) and type 2 (CB2), which are candidate molecules involved in the modulation of synaptic transmission. Dot-like CB1 immunoreactivity was distributed in the perinuclear cytoplasm of chemoreceptor cells immunoreactive for the catecholamine-synthesizing enzymes, tyrosine hydroxylase and dopamine beta-hydroxylase. Furthermore, CB1 immunoreactivity was observed in sensory nerve endings immunoreactive for P2X3 purinoceptors that colocalized with vesicular glutamate transporter 2. On the other hand, immunoreactivity for CB2 was mainly distributed in chemoreceptor cells, and was weakly observed in sensory nerve endings immunoreactive for P2X2 purinoceptors. The present results suggest that CB1 and CB2 regulate the release of catecholamines and glutamate from chemoreceptor cells and sensory nerve endings, respectively. Therefore, CB1 and CB2 may be involved in synaptic plasticity in the carotid body.

Type 2 vomeronasal receptor expression in the olfactory organ of African lungfish, Protopterus annectens.

The olfactory organ of tetrapods, with few exceptions, comprises the main and accessory organs: olfactory epithelium (OE) and vomeronasal organ (VNO). Unlike tetrapods, teleost fish lack a VNO. However, lungfish, a type of sarcopterygian fish closely related to tetrapods, possesses a lamellar OE similar to the OE of teleosts and a recess epithelium (RecE) resembling the amphibian VNO. The RecE has been hypothesized as a primordial VNO. Olfactory receptors in tetrapods are distinctively expressed in the OE and VNO. For instance, type 2 vomeronasal receptors (V2Rs) in Xenopus are categorized into those exclusively expressed in the OE and those solely expressed in the VNO. It remains unclear whether V2Rs are differentially expressed between the lamellar OE and RecE in lungfish. This study investigated V2R expression in the lamellar OE and RecE of the African lungfish, Protopterus annectens. P. annectens V2Rs were categorized into three groups: those exclusively expressed in the lamellar OE, those exclusively expressed in the RecE, and those expressed in both the lamellar OE and RecE. V2Rs exclusively expressed in the RecE and those expressed in both the lamellar OE and RecE formed a distinct clade in the phylogenetic tree, whereas others were solely expressed in the lamellar OE. These findings suggest that lungfish V2R expression represents an intermediate stage toward complete segregation between V2Rs expressed in the OE and those expressed in the VNO.

Distribution and morphology of serotonin transporter-immunoreactive type I cells in the rat carotid body.

The present study reexamined the immunolocalization of membranous serotonin transporter (SERT) in the rat carotid body, and demonstrated SERT-immunoreactive cells of unreported morphology. SERT was immunohistochemically localized in a very small population of cell clusters or single type I cells (2.8%) immunoreactive for synaptophysin, the marker of these cells. Intense SERT immunoreactivity outlined the perinuclear cytoplasm and multiple cytoplasmic processes of type I cells. Of SERT-immunoreactive type I cells, 14.6% and 32.6% were immunoreactive for tyrosine hydroxylase (TH) and dopamine beta-hydroxylase, respectively, while 75.9% were immunoreactive for serotonin (5-HT). 5-HT-immunoreactive products were localized in cell bodies rather than cytoplasmic processes. SERT-immunoreactive type I cells were composed of an oval cell body with multiple threads and spherical or elongated cytoplasmic processes. Clusters or single SERT-immunoreactive type I cells were localized between or attached to other TH-immunoreactive type I cells by cell bodies or variform cytoplasmic processes. SERT-immunoreactive type I cells mainly contained bassoon-immunoreactive products in their cell bodies rather than their variform cytoplasmic processes. These results demonstrated the characteristic morphology of SERT-immunoreactive type I cells, which extend multiple cytoplasmic processes with variform terminal parts. Their morphology might be suitable for uptake of 5-HT to control the serotonergic modulation in the carotid body.

Three-Dimensional Ultrastructure of Flower-Spray Nerve Endings in the Rat Carotid Sinus.

The flower-spray nerve endings are afferent nerve terminals in the carotid sinus that arise from carotid sinus nerve of glossopharyngeal nerve. However, the three-dimensional ultrastructural characteristics of flower-spray nerve endings and spatial relationships between the terminal parts and other cellular elements have not been fully understood. To elucidate their detailed relationship, backscattered electron imaging of serial sections was performed with a scanning electron microscope to produce a three-dimensional reconstruction of the flower-spray endings. The terminal parts of flower-spray endings were distributed horizontally approximately 5 µm outside the external elastic membrane in the tunica adventitia of the internal carotid artery. The three-dimensional reconstruction showed that the terminal parts of flower-spray endings were flat with irregular contours and were partially covered by the thin cytoplasmic processes of Schwann cells. The complex consisting of the nerve terminals and associated Schwann cells was surrounded by a multilayered basement membrane. The terminal parts of the endings were also surrounded by fibroblasts with elastic fibers and collagen fibrils. Secretory vesicles without an electron-dense core were observed in the terminal parts of the endings. The accumulation of vesicles just below the axonal membrane was observed in terminal parts not covered by Schwann cell cytoplasmic processes on both the luminal and basal sides. Swollen mitochondria, concentric membranous structures, and glycogen granule-like electron-dense materials were often noted in some of the terminal parts of the endings and the parent axon. Collectively, the present results suggest that flower-spray endings are baroreceptors because their morphology was similar to other mechanoreceptors. Furthermore, flower-spray endings may be affected by glutamate secreted in an autocrine manner.

Immunohistochemical analysis and distribution of epithelial mast cells in the rat larynx and trachea.

Mast cells (MCs) in rat airways have been classified into two subtypes: epithelial MCs and connective tissue MCs (CTMCs). However, the immunohistochemical characteristics, cellular morphology, and distribution of epithelial MCs in the upper airways remain unclear. The present study investigated the morphological characteristics and distribution of epithelial MCs using 5-hydroxytryptamine (5-HT) and other immunohistochemical markers in sectioned or whole-mount preparations of the rat larynx and trachea. A double immunofluorescence analysis revealed the colocalization of 5-HT immunoreactivity with c-kit, a stem cell factor receptor commonly used as a MC marker, in both epithelial MCs and CTMCs. Dopa decarboxylase, an enzyme involved in 5-HT synthesis, was detected in both subtypes, suggesting their ability to synthesize and release 5-HT. Tryptase and histidine decarboxylase (a biosynthetic enzyme of histamine), which are well-known mediators of MCs, were exclusive to CTMCs. Epithelial MCs were pleomorphic with long cytoplasmic processes, whereas CTMCs were round and lacked cytoplasmic processes. The density of epithelial MCs was significantly higher in the glottis and cranial part of the trachea than in the epiglottis and other parts of the trachea. The present results showed that the morphology and immunohistochemical characteristics of epithelial MCs were different from those of CTMCs in the rat larynx and trachea, and variform epithelial MCs were predominantly located at the entrance of the upper airways. Epithelial MCs may release 5-HT to regulate innate immune responses by modulating epithelial cell functions at the entrance gate of the upper airways.

Immunohistochemical localization of proteins involved in exocytosis of glutamate from P2X3 purinoceptor-expressing subserosal afferent nerve endings in the rat gastric antrum.

We previously reported the presence of P2X3 purinoceptors (P2X3)-expressing subserosal afferent nerve endings consisting of net- and basket-like nerve endings in the rat gastric antrum. These nerve endings may morphologically be vagal mechanoreceptors activated by antral peristalsis. The present study investigated immunoreactivities for vesicular glutamate transporter (VGLUT) 1 and VGLUT2 as well as exocytosis-related proteins, i.e., core components of the SNARE complex (SNAP25, Stx1, and VAMP2) and synaptotagmin-1 (Syt1), in whole-mount preparations of the rat gastric antrum using double immunofluorescence. VGLUT1 immunoreactivity was not detected, whereas VGLUT2 immunoreactivity was observed in P2X3-immunoreactive subserosal nerve endings composed of both net- and basket-like endings. In net-like nerve endings, intense VGLUT2 immunoreactivity was localized in polygonal bulges of reticular nerve fibers and peripheral axon terminals. Furthermore, intense immunoreactivities for SNAP25, Stx1, and VAMP2 were localized in net-like nerve endings. Intense immunoreactivities for VAMP2 and Syt1 were observed in VGLUT2-immunoreactive net-like nerve endings. In basket-like nerve endings, VGLUT2 immunoreactivity was localized in pleomorphic terminal structures and small bulges surrounding the subserosal ganglion, whereas immunoreactivities for SNAP25, Stx1, and VAMP2 were weak in these nerve endings. VGLUT2-immunoreactive basket-like nerve endings were weakly immunoreactive for VAMP2 and Syt1. These results suggest that subserosal afferent nerve endings release glutamate by exocytosis mainly from net-like nerve endings to modulate their mechanoreceptor function.

Responsiveness of the Zurich Claudication Questionnaire in Patients With Lumbar Spinal Stenosis Undergoing Nonsurgical Treatment: A Secondary Analysis of a Randomized Controlled Trial.

STUDY DESIGN: Secondary analysis of a randomized controlled trial. OBJECTIVE: We investigated the ability to distinguish patients with lumbar spinal stenosis (LSS) who improved from those who did not after receiving nonsurgical treatment. We used the disorder-specific Zurich Claudication Questionnaire (ZCQ) satisfaction subscale as an external anchor and estimated the minimal clinically important differences (MCIDs) for the ZCQ symptom severity and physical function subscales. SUMMARY OF BACKGROUND DATA: The ZCQ satisfaction subscale effectively distinguishes surgical patients who improved from those who did not for LSS. However, its responsiveness in nonsurgical treatment has not been evaluated yet. METHODS: Eighty-four patients with LSS who received supervised physical therapy or a home exercise program were included. Patients were classified as responders or nonresponders according to the cutoff of 2.5 for the ZCQ satisfaction subscales at six weeks and one year. The external responsiveness of the ZCQ satisfaction subscale was assessed using correlational and receiver-operating characteristic (ROC) curve analyses. MCIDs for the ZCQ symptom severity and physical function subscales were estimated using anchor and distribution approaches. RESULTS: Pearson correlation coefficients between the changes in outcomes and the ZCQ satisfaction subscale at six weeks and one year were 0.37 to 0.58 (symptom severity) and 0.40 to 0.45 (physical function subscales) (>0.30 is considered a good anchor). The area under the ROC curve values were 0.66 to 0.72 and 0.63 to 0.71 for the symptom severity and physical function subscales, respectively (>0.7 is considered acceptable). The MCIDs at six weeks and one year estimated from anchor-based approaches were -0.64 to -0.13 (symptom severity) and -0.39 to 0.10 (physical function), and those from the distribution-based approaches were -0.31 to -0.30 and -0.29 to -0.27, respectively. CONCLUSIONS: The findings of this study suggest that the ZCQ satisfaction subscale has less ability to distinguish patients with LSS who improved in the ZCQ symptom severity and physical function subscales from those who did not after nonsurgical treatment, compared to those after surgical treatment.

Immunohistochemical localization of P2Y12 purinoceptors in the rat carotid body.

The present study investigated the localization of the adenosine 5'-diphosphate (ADP)-selective P2Y12 purinoceptors in the rat carotid body using multilabeling immunofluorescence. Punctate immunoreactive products for P2Y12 were distributed in chemoreceptive type I cells immunoreactive to vesicular nucleotide transporter (VNUT) or dopamine beta-hydroxylase, but not in S100B-immunoreactive glial-like type II cells. P2Y12 immunoreactivity was localized in cell clusters containing VNUT-immunoreactive type I cells surrounded by the perinuclear cytoplasm and cytoplasmic processes of type II cells immunoreactive for ectonucleoside triphosphate diphosphohydrolase 2 (NTPDase2) and NTPDase3, which hydrolyze extracellular nucleotide tri- and/or di-phosphates. In ATP bioluminescence assays using carotid bodies, the degradation of extracellular ATP was attenuated in the presence of the selective NTPDases inhibitor ARL67156, suggesting ATP-degrading activity by NTPDases in the tissue. These results suggest that ATP released from type I cells is degraded into ADP and adenosine 5'-monophosphate by NTPDases expressed in type II cells, and that ADP modulates type I cells via P2Y12 purinoceptors.

Suspected renal interstitial cell tumor causing polycythemia in two dogs.

Here we report a case series of two dogs diagnosed as renal interstitial cell tumor (RICT) accompanied by elevated serum erythropoietin level and marked polycythemia. RICT is a rare tumor in dogs, originating from renal interstitial cells. While several renal tumors such as renal lymphoma, adenocarcinoma, carcinoma, sarcoma, fibrosarcoma and nephroblastoma may cause polycythemia, polycythemia caused by RICT has never been reported in dogs. The tumors in both dogs were solitary and lied within cortex or cortico-medullary junction. Histopathology revealed spindle-shaped cells suggesting mesenchymal origin, with no mitotic figures suggesting that the tumors in both dogs were benign. Following surgical removal of the affected kidney, serum erythropoietin level and polycythemia normalized in both dogs.

Origin and spatial population structure of Malagasy native chickens based on mitochondrial DNA.

Since Malagasy human culture became established in a multi-layered way by genetic admixture of Austronesian (Indonesia), Bantu (East Africa) and West Asian populations, the Malagasy native livestock should also have originated from these regions. While recent genetic studies revealed that Malagasy native dogs and goats were propagated from Africa, the origin of Malagasy native chickens is still controversial. Here, we conducted a phylogeographic analysis of the native chickens, focusing on the historical relationships among the Indian Ocean rim countries and based on mitochondrial D-loop sequences. Although previous work suggested that the rare Haplogroup D occurs with high frequencies in Island Southeast Asia-Pacific, East Africa and Madagascar, the major mitochondrial lineage in Malagasy populations is actually not Haplogroup D but the Sub-haplogroup C2, which is also observed in East Africa, North Africa, India and West Asia. We demonstrate that the Malagasy native chickens were propagated directly from West Asia (including India and North Africa), and not via East Africa. Furthermore, they display clear genetic differentiation within Madagascar, separated into the Highland and Lowland regions as seen in the human genomic landscape on this island. Our findings provide new insights for better understanding the intercommunion of material/non-material cultures within and around Madagascar.

Minimal clinically important differences in walking capacity and physical activity after nonsurgical treatment in patients with lumbar spinal stenosis: a secondary analysis of a randomized controlled trial.

BACKGROUND CONTEXT: Little information is available about the minimal clinically important differences (MCIDs) for objective physical measurements in people with lumbar spinal stenosis (LSS). PURPOSE: To use disorder-specific anchor and, multiple anchor-, and distribution-based approaches to determine the MCIDs for walking capacity and physical activity in patients with LSS receiving nonsurgical treatment. STUDY DESIGN/SETTING: Secondary analysis of a randomized controlled trial. PATIENT SAMPLE: Sixty-nine patients with neurogenic claudication caused by LSS receiving outpatient physical therapy. OUTCOME MEASURES: Zurich claudication questionnaire (ZCQ), self-paced walking test (SPWT), and number of daily steps measured by pedometry. METHODS: All patients completed the ZCQ, SPWT, and pedometry at the baseline and after 6 weeks. For the anchor-based approach, ZCQ symptom severity, physical function, and satisfaction subscales were used as the external anchors. Using the receiver-operating characteristic (ROC) curve, the MCIDs were determined based on the optimal cutoff points for changes in the SPWT or daily steps. For the distribution-based approach, the MCIDs were estimated from the standard deviations (SDs) of the baseline scores of the SPWT and daily steps. RESULTS: In the anchor-based approach, only the ZCQ satisfaction subscale for the SPWT (0.73), and ZCQ symptom severity subscale for daily steps (0.71) exceeded the area under the ROC curve value of 0.7, which is considered acceptable. When using these subscales as anchors, the ROC curves and optimal cutoff points indicated MCIDs of 151 m for the SPWT and 1,149 steps for daily steps. The distribution-based approach estimated the MCIDs as 280 m for the SPWT and 1,274 steps for daily steps, and had a moderate effect size (0.5 SD). CONCLUSIONS: The anchor-based approach had limited external responsiveness when the ZCQ was used as the anchor. However, this information may be helpful for interpreting walking capacity and physical activity in patients with LSS receiving nonsurgical treatment and for estimating power and sample size when planning new trials.

ADP-mediated Modulation of Intracellular Calcium Responses in Chromaffin Cells: The Role of Ectonucleoside Triphosphate Diphosphohydrolase 2 on Rat Adrenal Medulla Function.

The present study investigated the localization and the adenosine 5'-triphosphate (ATP)-degrading function of the plasma membrane-bound ecto-nucleotidase, ectonucleoside triphosphate diphosphohydrolase 2 (NTPDase2), in the rat adrenal medulla. The effect of ATP degradation product, adenosine 5'-diphosphate (ADP), on carbachol (CCh)-induced intracellular Ca2+ ([Ca2+]i) responses in adrenal chromaffin cells was examined using calcium imaging. NTPDase2-immunoreactive cells were distributed between chromaffin cells. NTPDase2-immunoreactive cells were immunoreactive for glial fibrillary acidic protein and S100B, suggesting that they were sustentacular cells. NTPDase2-immunoreactive cells surrounded chromaffin cells immunoreactive for vesicular nucleotide transporter and P2Y12 ADP-selective purinoceptors. In ATP bioluminescence assays using adrenal medullary slices, ATP was rapidly degraded and its degradation was attenuated by the NTPDase inhibitors sodium polyoxotungstate (POM-1) and 6-N, N-diethyl-d-ß,γ-dibromomethylene ATP (ARL67156). ADP inhibited CCh-induced [Ca2+]i increases of chromaffin cells in adrenal medullary slices. The inhibition of CCh-induced [Ca2+]i increases by ADP was blocked by the P2Y12 purinoceptor antagonist AZD1283. CCh-induced [Ca2+]i increases were also inhibited by the P2Y1, P2Y12, and P2Y13 purinoceptor agonist 2-methylthioadenosine diphosphate trisodium (2MeSADP), in combination with the P2Y1 purinoceptor antagonist MRS2179. These results suggest that sustentacular cells express NTPDase2 to degrade ATP released from adrenal chromaffin cells, and ADP modulates the excitability of chromaffin cells via P2Y12 purinoceptors to regulate catecholamine release during preganglionic sympathetic stimuli. (J Histochem Cytochem 72: 41-60, 2024).

Morphological Analysis of the Olfactory System of the Pig-Nosed Turtle, Carettochelys insculpta.

The turtle olfactory organ consists of the upper (UCE) and lower (LCE) chamber epithelium, projecting to the ventral and dorsal parts of the olfactory bulbs, respectively. The UCE is associated with glands, contains ciliated olfactory receptor neurons, and is assumed to detect odorants primarily in air, while the LCE is devoid of glands, contains microvillous olfactory receptor neurons, and is assumed to detect odorants primarily in water. Examining the olfactory system of the pig-nosed turtle, Carettochelys insculpta, this study found that both the upper and lower chambers of the nasal cavity were lined with sensory epithelium devoid of associated glands and contained ciliated olfactory receptor neurons. Moreover, the olfactory bulbs were not divided into dorsal and ventral parts. These results suggest that the olfactory system of the pig-nosed turtle is a single system specialized for detecting odorants in water.

In situ hybridization analysis of odorant receptor expression in the olfactory organ of the pig-nosed turtle Carettochelys insculpta.

The turtle olfactory organ consists of upper (UCE) and lower (LCE) chamber epithelium, which send axons to the ventral and dorsal portions of the olfactory bulbs, respectively. Generally, the UCE is associated with glands and contains ciliated olfactory receptor neurons (ORNs), while the LCE is devoid of glands and contains microvillous ORNs. However, the olfactory organ of the pig-nosed turtle Carettochelys insculpta appears to be a single olfactory system morphologically: there are no associated glands; ciliated ORNs are distributed throughout the olfactory organ; and the olfactory bulb is not divided into ventral and dorsal portions. In this study, we analyzed the expression of odorant receptors (ORs), the major olfactory receptors in turtles, in the pig-nosed turtle olfactory organ, via in situ hybridization. Of 690 ORs, 375 were classified as class I and 315 as class II. Some class II ORs were expressed predominantly in the posterior dorsomedial walls of the nasal cavity, while other class II ORs and all class I ORs examined were expressed in the remaining region. These results suggest that the pig-nosed turtle olfactory organ can be divided into two regions according to the expression of ORs.

Expression patterns of the transcription factors Fezf1, Fezf2, and Bcl11b in the olfactory organs of turtle embryos.

Many tetrapod vertebrates have two distinct olfactory organs, the olfactory epithelium (OE) and vomeronasal organ (VNO). In turtles, the olfactory organ consists of two types of sensory epithelia, the upper chamber epithelium (UCE; corresponding to the OE) and the lower chamber epithelium (LCE; corresponding to the VNO). In many turtle species, the UCE contains ciliated olfactory receptor cells (ORCs) and the LCE contains microvillous ORCs. To date, several transcription factors involved in the development of the OE and VNO have been identified in mammals. Fez family zinc-finger protein 1 and 2 (Fezf1 and 2) are expressed in the OE and VNO, respectively, of mouse embryos, and are involved in the development and maintenance of ORCs. B-cell lymphoma/leukemia 11B (Bcl11b) is expressed in the mouse embryo OE except the dorsomedial parts of the nasal cavity, and regulates the expression of odorant receptors in the ORCs. In this study, we examined the expression of Fezf1, Fezf2, and Bcl11b in the olfactory organs of embryos in three turtle species, Pelodiscus sinensis, Trachemys scripta elegans, and Centrochelys sulcata, to evaluate their involvement in the development of reptile olfactory organs. In all three turtle species, Bcl11b was expressed in the UCE, Fezf2 in the LCE, and Fezf1 in both the UCE and LCE. These results imply that the roles of the transcription factors Fezf1, Fezf2, and Bcl11b in olfactory organ development are conserved among mammals and turtles.

Three-dimensional architecture of the subepithelial corpuscular nerve ending in the rat epiglottis reconstructed by array tomography with scanning electron microscopy.

In the rat laryngeal mucosa, subepithelial corpuscular nerve endings, called laminar nerve endings, are distributed in the epiglottis and arytenoid region and are activated by the pressure changes of the laryngeal cavity. They are also suggested to play a role in efferent regulation because of secretory vesicles in the axoplasm. In the present study, the laminar nerve endings in the rat laryngeal mucosa were analyzed by 3D reconstruction from serial ultrathin sections in addition to immunohistochemistry for synapsin 1. In the light microscopy, synapsin 1-immunoreactive flattened or bulbous terminal parts of the laminar endings were also immunoreactive with VGLUT1, and were surrounded by S100- or S100B-immunoreactive Schwann cells and vimentin-immunoreactive fibroblasts. In the electron microscopy, 3D reconstruction views showed that laminar endings were composed of flattened terminal parts sized 2-5 µm in longitudinal length, overlapping in three to five multiple layers. The terminal parts of the endings were incompletely wrapped by flat cytoplasmic processes of the Schwann cells. In addition, the fibroblast network surrounded the complex of nerve endings and the Schwann cells. Several terminal parts entered through the basement membrane into the epithelial layer and attached to the basal epithelial cells, suggesting that interaction between epithelial cells and laminar nerve endings plays an important role in sensing the pressure changes in the laryngeal cavity. Secretory vesicles were unevenly distributed throughout the terminal part of the laminar nerve endings. The secretory vesicles were frequently observed in the peripheral limb of the terminal parts. It suggests that the laminar nerve endings in the larynx may release glutamate to maintain continuous discharge during the stretching of the laryngeal mucosa.

Expression of type 1 vomeronasal receptors in the olfactory organ of the African lungfish, Protopterus dolloi.

The vomeronasal organ is an olfactory organ found in amphibians and higher vertebrates. Type 1 vomeronasal receptors, one of the major olfactory receptors in vertebrates, are expressed in the vomeronasal organ in mammals. In amphibians and fish, they are expressed in the olfactory epithelium. The lungfish, which is the species of fish most closely related to amphibians, has a primitive vomeronasal organ: the recess epithelium. Expression of type 1 vomeronasal receptors has been reported in both the olfactory epithelium and the recess epithelium in three species of African lungfish and one species of South American lungfish. However, a previous study suggested that in the African lungfish Protopterus dolloi these receptors are expressed only in the olfactory epithelium. In this study, we identified 21 type 1 vomeronasal receptor genes in P. dolloi and examined the expression sites in the olfactory organ. In P. dolloi, most cells expressing the type 1 vomeronasal receptor were distributed in the olfactory epithelium, but a few were also found in the recess epithelium. This implies that the functions of the olfactory epithelium and the primitive vomeronasal organ are incompletely separated, and that all extant African and South American lungfish share this trait.

Lumbar paraspinal muscle morphology is associated with spinal degeneration in patients with lumbar spinal stenosis.

BACKGROUND CONTEXT: Lumbar spinal stenosis (LSS) has been reported to induce changes in paraspinal muscle morphology, but objective physical function and degenerative spine conditions are rarely assessed. PURPOSE: To identify factors associated with paraspinal muscle morphology using objective physical and degenerative spine assessments in patients with LSS. STUDY DESIGN/SETTING: Cross-sectional design. PATIENT SAMPLE: Seventy patients with neurogenic claudication caused by LSS, receiving outpatient physical therapy. OUTCOME MEASURES: Cross-sectional area (CSA) and functional CSA (FCSA) of the multifidus, erector spinae, and psoas muscles, the severity of stenosis, disc degeneration, and endplate abnormalities were evaluated by magnetic resonance imaging, as well as sagittal spinopelvic alignment by X-ray. Objective physical assessments included pedometry and claudication distance. Patient-reported outcomes included the numerical rating scale of low back pain, leg pain, and leg numbness, and the Zurich Claudication Questionnaire. METHODS: To assess the impact of LSS on paraspinal muscles, FCSA and FCSA/CSA were compared between the dominant and nondominant sides based on the patients' neurogenic symptoms, and multivariable regression analyses adjusted for age, sex, height, and weight were performed; p<.05 was considered significant. RESULTS: Seventy patients were analyzed. At one level below the maximum stenotic level, erector spinae FCSA on the dominant side was significantly lower than that on the nondominant side. In the multivariable regression analyses, at one level below the symptomatic level, disc degeneration, endplate abnormalities, and lumbar spinopelvic alignment, such as decreased lumbar lordosis and increased pelvic tilt, were negatively associated with multifidus FCSA and FCSA/CSA ratio. A significant association was observed between dural sac CSA and erector spinae FCSA. Throughout L1/2 to L5/S, disc degeneration, endplate abnormalities, and lumbar spinopelvic alignment were negatively associated with multifidus and erector spinae FCSA or FCSA/CSA. CONCLUSIONS: Lumbar paraspinal muscle asymmetry caused by LSS was observed only in erector spinae. Disc degeneration, endplate abnormalities, and lumbar spinopelvic alignment, rather than spinal stenosis and LSS symptoms, were more associated with paraspinal muscle atrophy or fat infiltration.

In situ hybridization analysis of olfactory receptor expression in the sea turtle olfactory organ.

The olfactory organ of turtles consists of an upper chamber epithelium (UCE) with associated glands, and a lower chamber epithelium (LCE) devoid of glands. The UCE and LCE are referred to as the air-nose and the water-nose, respectively, because the UCE is thought to detect airborne odorants, while the LCE detects waterborne odorants. However, it is not clear how the two are used in the olfactory organ. Odorant receptors (ORs) are the major olfactory receptors in turtles; they are classified as class I and II ORs, distinguished by their primary structure. Class I ORs are suggested to be receptive to water-soluble ligands and class II ORs to volatile ligands. This study analyzed the expression of class I and II ORs in hatchlings of the green sea turtle, Chelonia mydas, through in situ hybridization, to determine the localization of OR-expressing cells in the olfactory organ. Class I OR-expressing cells were distributed mainly in the LCE, implying that the LCE is receptive to waterborne odorants. Class II OR-expressing cells were distributed in both the UCE and LCE, implying that the entire olfactory organ is receptive to airborne odorants. The widespread expression of class II ORs may increase opportunities for sea turtles to sense airborne odorants.