[Successful Treatment with TACE and RFA for a Hepatocellular Carcinoma Case with Lung Metastasis].

We report a hepatocellular carcinoma(HCC)case with lung metastasis that was successfully treated with transarterial chemoembolization(TACE)and percutaneous radiofrequency ablation(RFA). A man in his 60s took right robe liver resection for HCC after TACE for its rupture. Lung metastasis occurred at S1+2 and S6 in the left lung, and an adverse event interrupted standard molecular target therapies. Because extrahepatic metastasis had been seen only in these two locations for a long time, TACE was performed for both metastases. The feeders for both lesions were each intercostal artery, and controlling the drug inflow was necessary to avoid drug influx into the spinal cord branches when S6 metastasis was treated. The viable lesion remained in the S6 lesion, so RFA was added for both lung metastases. 100% tumor necrosis has been observed since the RFA.

A Phylogenetically Distinct Group of Glandirana rugosa Found in Kyushu, Japan.

The Japanese wrinkled frog Glandirana rugosa is separated into five genetically different groups. One group in western Japan is further divided into three subgroups, found in Kyushu, Shikoku, and western Honshu. We collected G. rugosa frogs at 39 sites in Kyushu and determined nucleotide sequences of the mitochondrial 12S and 16S rRNA genes for phylogenetic analysis. Unexpectedly, we found a group of frogs in southeastern Kyushu that did not cluster with any of the pre-existing five groups of G. rugosa on the phylogenetic trees. The frogs in the new group and G. rugosa in Kyushu were externally similar, but there were a few significant differences in morphological features between the two populations. In addition, we observed significant differences in the frogs' calls . Thus, the group of the frogs in southeastern Kyushu may represent a new candidate species in the genus Glandirana. We discuss the possibility of a new species.

Melatonin is a potential drug for the prevention of bone loss during space flight.

Astronauts experience osteoporosis-like loss of bone mass because of microgravity conditions during space flight. To prevent bone loss, they need a riskless and antiresorptive drug. Melatonin is reported to suppress osteoclast function. However, no studies have examined the effects of melatonin on bone metabolism under microgravity conditions. We used goldfish scales as a bone model of coexisting osteoclasts and osteoblasts and demonstrated that mRNA expression level of acetylserotonin O-methyltransferase, an enzyme essential for melatonin synthesis, decreased significantly under microgravity. During space flight, microgravity stimulated osteoclastic activity and significantly increased gene expression for osteoclast differentiation and activation. Melatonin treatment significantly stimulated Calcitonin (an osteoclast-inhibiting hormone) mRNA expression and decreased the mRNA expression of receptor activator of nuclear factor κB ligand (a promoter of osteoclastogenesis), which coincided with suppressed gene expression levels for osteoclast functions. This is the first study to report the inhibitory effect of melatonin on osteoclastic activation by microgravity. We also observed a novel action pathway of melatonin on osteoclasts via an increase in CALCITONIN secretion. Melatonin could be the source of a potential novel drug to prevent bone loss during space flight.

Nanos3 of the frog Rana rugosa: Molecular cloning and characterization.

Nanos is expressed in the primordial germ cells (PGCs) and also the germ cells of a variety of organisms as diverse as Drosophila, medaka fish, Xenopus and mouse. In Nanos3-deficient mice, PGCs fail to incorporate into the gonad and the size of the testis and ovary is thereby dramatically reduced. To elucidate the role of Nanos in an amphibian species, we cloned Nanos3 cDNA from the testis of the R. rugosa frog. RT-PCR analysis showed strong expression of Nanos3 mRNA in the testis of adult R. rugosa frogs, but expression was not sexually dimorphic during gonadal differentiation. In Nanos3-knockdown tadpoles produced by the CRISPR/Cas9 system, the number of germ cells decreased dramatically in the gonads of both male and female tadpoles before sex determination and thereafter. This was confirmed by three dimensional imaging of wild-type and Nanos3 knockdown gonads using serial sections immunostained for Vasa, a marker specific to germ cells. Taken together, these results suggest that Nanos3 protein function is conserved between R. rugosa and mouse.

Cost-Effectiveness Analysis of Percutaneous Sclerotherapy for Venous Malformations.

PURPOSE: To assess cost-effectiveness of sclerotherapy for venous malformations (VMs) to improve patient quality of life (QOL). MATERIALS AND METHODS: This prospective study enrolled 28 patients with symptomatic VMs who underwent sclerotherapy. EuroQol-5 Dimension (EQ-5D) and Short-Form 36 (SF-36) Health Survey were used to measure health-related QOL. Questionnaires were collected before and 1, 3, 6, and 12 months after sclerotherapy. Quality-adjusted life years (QALYs) were calculated using EQ-5D score as a measure of health utility. Medical costs obtained from the hospital accounting system and other costs of staff, drugs, materials, and angiographic equipment were calculated for each procedure. Cost-effectiveness was analyzed using incremental cost-effectiveness ratio (ICER) as the medical cost/gain of QALYs. RESULTS: Median EQ-5D scores improved from 0.768 (range, 0.705-1) to 1 (range, 0.768-1) after 6 months (P = .023) and 1 (range, 0.768-1) after 12 months (P = .063). The gain of QALYs at 12 months was 0.043. The mean medical cost was ¥281,228 ($2,337). The pain group (baseline bodily pain scale of SF-36 score < 70) showed greater improvement in median EQ-5D score, from 0.705 (range, 0.661-0.768) to 0.768 (range, 0.705-1) after 6 months (P = .041) and 0.768 (range, 0.768-1) after 12 months (P = .049). ICER at 12 months was ¥6,600,483 ($54,840) in the overall group and decreased to ¥3,998,113 ($33,218) in the pain group, < ¥6,000,000 ($49,850), threshold for acceptance of a public health benefit in Japan, even accounting for 50% increase in costs. CONCLUSIONS: Sclerotherapy was cost-effective for improving QOL for symptomatic VMs, especially for patients with moderate to severe pain.

Patient satisfaction after sclerotherapy of venous malformations in children.

BACKGROUND: We have introduced and performed percutaneous sclerotherapy on pediatric patients, and information regarding the mid- and long-term results after percutaneous treatment of peripheral venous malformations is necessary to counsel patients and their parents about the outcome of the therapy. This study was designed to retrospectively evaluate the long-term satisfaction of pediatric patients following percutaneous sclerotherapy for venous malformations (VMs). METHODS: A total of 53 children younger than 16 years of age with VMs who underwent sclerotherapy were included in this study. Self-assessment questionnaires regarding the treatment effectiveness and patients' satisfaction were sent to 50 of 53 patients. Sclerotherapy was performed using 3% polidocanol, absolute ethanol, or 5% ethanolamine oleate (EO). RESULTS: The median numbers of sessions per patient was 2.0 (range, 1-12), and the median follow-up time was 1.8 years (range, 6months-8.3years). Forty-two patients (84%) returned the questionnaire. The most frequent symptom was swelling (95%, 40/42) before sclerotherapy. After treatment, patients felt less pain (82%, 23/28), functional limitation (78%, 14/18), swelling (70%, 28/40), and cosmetic disfigurement (59%, 13/22). None of the patients responded "worse" for any symptoms, and 30 patients (71%) reported being "very satisfied" or "satisfied" with the treatment. CONCLUSION: Percutaneous sclerotherapy of VMs was safe and effective for relieving symptoms in our pediatric patients, and many of them were satisfied with the outcomes.

Embolic effects of transcatheter mesenteric arterial embolization with microspheres on the small bowel in a dog model.

PURPOSE: To determine the arterial distribution and ischemic effects of various particle sizes after transcatheter embolization of the small bowel in a dog model. MATERIALS AND METHODS: In 10 dogs, selective microsphere embolization was performed in six branches of the superior mesenteric artery. Microspheres were allocated into three size ranges (100-300 µm, 300-500 µm, and 500-700 µm) and four volume concentrations (0.625%, 1.25%, 2.5%, and 5%). For each size and volume concentration, embolization was performed of five branches at the origin of the last arcade. The distribution of microspheres and the range of ischemic changes of mucosa were evaluated histologically. Angiograms were categorized into two groups: group A, only the vasa recta nonopacified; group B, the last arcade or more proximal branches nonopacified. RESULTS: Microspheres sized 100-300 µm penetrated into intramural arteries and 500-700 µm microspheres mainly blocked arteries in the mesentery. There was a significant difference among three sizes in terms of the locations within the vasculature (P < .0001). The larger volume and the smaller size resulted in more ischemia. The range of ischemic changes among three sizes and among four volume concentrations was significantly different (P = .004 and P < .0001, respectively). The range of ischemic changes with 500-700 µm microspheres in group B was significantly greater than in group A (0% in group A vs 83% in group B, P = .001). CONCLUSIONS: In a dog model, embolization of the small bowel limited to the vasa recta with the use if 500-700 µm microspheres reduced the range of ischemic changes.

Long-term outcomes of coil packing for visceral aneurysms: correlation between packing density and incidence of coil compaction or recanalization.

PURPOSE: To evaluate the correlation between packing density and the incidence of coil compaction or recanalization of visceral artery aneurysms (VAAs) after coil packing. MATERIALS AND METHODS: Between July 2004 and April 2012, coil packing was performed for 46 true visceral aneurysms (16 splenic, 11 pancreaticoduodenal, eight renal, six hepatic, three superior mesenteric, one right gastric, and one gastroepiploic) in 42 patients. The size and volume of the aneurysm, packing density, and the incidences of compaction and recanalization were evaluated retrospectively. RESULTS: The mean follow-up period was 37 months ± 8 (range, 11-80 mo). The mean packing density was 19% ± 8 (range, 5%-42%), mean aneurysm size was 19 mm ± 8 (range, 5-40 mm), and mean volume was 4,108 mm(3) ± 5,435 (range, 72-26,235 mm(3)). Compaction and recanalization occurred in two (4%) and 12 aneurysms (26%), respectively. The mean packing density was significantly lower in aneurysms with compaction or recanalization than in unaffected aneurysms (12% vs 22%; P = .00014). There was a significant difference in mean packing density between small (< 20 mm; 22%) and large (≥ 20 mm) aneurysms (15%; P = .0045). The mean size and volume were significantly larger for coil-compacted or recanalized aneurysms than for unaffected aneurysms (P < .05). In aneurysms with a packing density of at least 24%, no compaction or recanalization occurred. CONCLUSIONS: Coil compaction or recanalization after coil packing for VAAs more often occurs after insufficient embolization with low packing density and in patients with large aneurysms.

Two case reports of two interventional radiology techniques for the treatment of stage II empyema: Hydrodissection and guidewire-dissection.

Empyema is an infection of the pleural space that is classified into 3 stages. Video-assisted thoracoscopic surgery is recommended as the first-line approach for stage II acute empyema. The purpose of video-assisted thoracoscopic surgery is also achieved with hydrodissection and guidewire-dissection by breaking the septa mechanically in the pleural cavity. Hydrodissection and guidewire-dissection are techniques in which a contrast medium is administered at high pressure and a guidewire is inserted into the pleural cavity to break the septa, respectively. Hydrodissection and guidewire-dissection might be minimally invasive alternatives for the treatment of septated empyema.

Current status of embolic agents for liver tumor embolization.

Gelatin sponge and polyvinyl alcohol particles have been the most popular particulate embolic agents for transarterial chemoembolization (TACE) of liver tumors. Over the last decade, calibrated microspheres have been introduced and increasingly used in liver tumor embolization in Western countries. In addition, drug-eluting beads (DEB) have been introduced for sustained local drug release. Such long-awaited spherical embolic agents will be introduced in Japan in the near future. The advantages of these microspheres are that particles are uniform in size and shape, and easy to inject through a microcatheter. They can travel distally to vessels corresponding to the particle size; in other words, the occlusion level can be predicted according to the particle size chosen. Thus, new bland microspheres and DEB may bring a significant advancement to embolization for primary liver tumors as well as hepatic metastases from various cancers. However, at this point, the published data suggests that both conventional TACE and DEB-TACE are equally effective for treatment of unresectable hepatocellular carcinoma, when patients are carefully selected. Therefore, indication, patient selection, and embolization techniques will be essential in order to individually adapt newer embolic agents based on oncological, anatomical and technical considerations.

Estrogen biosynthesis in the gonad of the frog Rana rugosa.

In certain species of amphibians gonadal differentiation is influenced by steroid hormones. In the case of the frog Rana rugosa testosterone given to tadpoles reverses sex from female to male, while the opposite reversal - male to female - can be achieved using estradiol-17ß. In this study, we investigated whether CYP19 (P450 aromatase), the enzyme responsible for a production of estradiol-17ß, was present in the differentiating gonad of R. rugosa. Initially, we immunized rabbits against frog CYP19 peptides and performed immunostaining using specific antibodies purified from that serum. CYP19-reactive signals were observed in gonadal somatic cells of the female, but not male tadpoles at stage (St.) I (the stage prior to phenotypic sex determination in tadpoles of R. rugosa). Immunopositive signals were also produced in ovarian somatic cells froglets at St. XXV (just after the completion of metamorphosis). We also examined the enzymatic activity of CYP19 in the differentiating gonad of R. rugosa. Reverse-phase HPLC (high performance liquid chromatography) analysis revealed that [(3)H]testosterone was converted to [(3)H]estradiol-17ß in the gonad of tadpoles at St. I. Interestingly, the rate of conversion was much higher in females than in males. To the best of our knowledge, this is the first report on the biosynthesis of estradiol-17ß in the gonad of amphibians, and the co-incident identification of active CYP19 enzyme in the differentiating gonad of R. rugosa. Based on our results, we conclude that estradiol-17ß may be involved in ovarian differentiation in this species.

Up-regulation of FSHR expression during gonadal sex determination in the frog Rana rugosa.

In vertebrates, gonadal production of steroid hormones is regulated by follicle-stimulating hormone (FSH) and luteinizing hormone (LH) via their receptors designated FSHR and LHR, respectively. We have shown recently that steroid hormones are synthesized in the differentiating gonad of tadpoles during sex determination in the frog Rana rugosa. To elucidate the role of gonadotropins (GTHs) and their receptors in the production of gonadal steroid hormones during sex determination, we isolated the full-length FSHß, LHß, FSHR and LHR cDNAs from R. rugosa and determined gonadal expression of FSHR (FSH receptor) and LHR (LH receptor) as well as brain expression of FSHß and LHß during sex determination in this species. The molecular structures of these four glycoproteins are conserved among different classes of vertebrates. FSHß expression was observed at similar levels in the whole brain (including the pituitary) of tadpoles, but it showed no sexual dimorphism during gonadal sex determination. By contrast, LHß mRNA was undetectable in the whole brain of tadpoles. FSHß-immunopositive cells were observed in the pituitary of female tadpoles with a differentiating gonad. Furthermore, FSHR expression was significantly higher in the gonad of female tadpoles during sex determination than in that of males, whereas LHR was expressed at similar levels in males and females. The results collectively suggest that FSHR, probably in conjunction with FSH, is involved in the steroid-hormone production during female-sex determination in R. rugosa.

Taxonomic identity of four groups of Glandirana rugosa (Anura, Ranidae) in Japan revealed by the complete mitochondrial genome sequence analysis.

The Japanese Glandirana rugosa phylogenetically consists of four groups. However, the taxonomic identity of these groups still remains unclear. We determined the complete mitogenome sequences of the four groups of G. rugosa. The mitogenomes were 17,394-17,781 bp in length. The phylogenetic analysis clearly showed that the genus Glandirana is monophyletic and that the four groups of G. rugosa are separated into two clusters: one cluster represents G. rugosa, the other cluster may represent a different species.

A threshold dosage of estrogen for male-to-female sex reversal in the Glandirana rugosa frog.

Steroid hormones play very important roles in gonadal differentiation in many vertebrate species. Previously, we have determined a threshold dosage of testosterone (T) to induce female-to-male sex reversal in Glandirana rugosa frogs. Genetic females formed a mixture of testis and ovary, the so-called ovotestis, when tadpoles of G. rugosa were reared in water containing the dosage of T, which enabled us to detect primary changes in the histology of the masculinizing gonads. In this study, we determined a threshold dosage of estradiol-17ß (E2) to cause male-to-female sex reversal in this frog. We observed first signs of histological changes in the ovotestes, when tadpoles were reared in water containing the dosage of E2. Ovotestes were significantly larger than wild-type testes in size. By E2 treatment, male germ cells degenerated in the feminizing testis leading to their final disappearance. In parallel, oocytes appeared in the medulla of the ovotestis and later in the cortex as well. Quantitative polymerase chain reaction analysis revealed that the expression of sex-related genes involved in testis formation was significantly decreased in the ovotestis. In addition, immuno-positive signals of CYP17 that is involved in testis differentiation in this frog disappeared in the medulla first and then in the cortex. These results suggested that oocytes expanded in the feminizing gonad (ovary) contemporaneously with male germ cell disappearance. Primary changes in the histology of the gonads during male-to-female sex reversal occurred in the medulla and later in the cortex. This direction was opposite to that observed during female-to-male sex reversal in the G. rugosa frog.

Blood flow modification might prevent secondary rupture of multiple pancreaticoduodenal artery arcade aneurysms associated with celiac axis stenosis.

A pancreaticoduodenal artery arcade aneurysm (PDAA) is rare and often associated with celiac axis stenosis by the median arcuate ligament. Although rupture risk of the PDAA is not related to its size, treatment guidelines are absent. Here we describe a 59-year-old woman with multiple ruptured PDAAs associated with celiac axis stenosis who was successfully treated with coil embolization. As follow-up computed tomography revealed rapid expansion of residual PDAAs and new gastric artery dissection, median arcuate ligament resection was followed by aorta-common hepatic artery bypass, which resulted in aneurysmal regression. Blood flow modification might prevent secondary rupture of PDAA associated with celiac axis stenosis.

Pleuroparenchymal fibroelastosis-like lesions in patients with interstitial pneumonia diagnosed by multidisciplinary discussion with surgical lung biopsy.

PURPOSE: The present study aimed to evaluate the significance of Pleuroparenchymal fibroelastosis (PPFE)-like lesions in predicting prognosis in patients with chronic interstitial pneumonia (IP). METHOD: The present study enrolled 207 patients with IP in whom surgical lung biopsy was performed. Among the patients enrolled in the present study, 77 had idiopathic pulmonary fibrosis (IPF), 15 had nonspecific interstitial pneumonia (NSIP), 13 had chronic hypersensitivity pneumonitis (CHP), 41 had connective tissue disease (CTD), three had PPFE, and 58 had unclassifiable diagnosis. The incidence, characteristics, and thickness of PPFE-like lesions were evaluated in each patient with IP. Additionally, the influence of PPFE-like lesions on the prognosis was also determined. RESULTS: Of 207 patients, 160 (77.3 %) showed PPFE-like lesions. The frequency of PPFE-like lesions was similar in patients with IPF, NSIP, CHP, CTD, and unclassifiable diagnosis (79.5 %, 79.5 %, 73.2 %, 65.9 %, and 81 %, respectively); however, PPFE-like lesions were present in all patients with PPFE (p = 0.42). Consequently, there was no significant difference in the characteristics of PPFE-like lesions among patients with all forms of IP, except PPFE. PPFE-like lesions were not a significant predictor of prognosis (hazard ratio [HR], 1.16; 95 % confidence interval [CI], 0.64-2.10, p = 0.62); however, patients with PPFE-like lesions under the aortic arch had significantly poorer prognoses (HR, 2.70; 95 % CI, 1.66-4.39, p < 0.001). For craniocaudal extent comparison, patients with IPF with PPFE-like lesions below the level of the carina had significantly poorer prognoses than those without PPFE-like lesions (p = 0.001, overall survival 53.1 and 80.6, respectively). CONCLUSION: PPFE-like lesions are common in patients with IP, and their characteristics were not significantly different among all forms of IP, except idiopathic PPFE. The broad extent of PPFE-like lesions is an important predictor of prognosis in patients with IPF.

Diversity in the origins of sex chromosomes in anurans inferred from comparative mapping of sexual differentiation genes for three species of the Raninae and Xenopodinae.

Amphibians employ genetic sex determination systems with male and female heterogamety. The ancestral state of sex determination in amphibians has been suggested to be female heterogamety; however, the origins of the sex chromosomes and the sex-determining genes are still unknown. In Xenopus laevis, chromosome 3 with a candidate for the sex- (ovary-) determining gene (DM-W) was recently identified as the W sex chromosome. This study conducted comparative genomic hybridization for X. laevis and Xenopus tropicalis and FISH mapping of eight sexual differentiation genes for X. laevis, X. tropicalis, and Rana rugosa. Three sex-linked genes of R. rugosa--AR, SF-1/Ad4BP, and Sox3--are all localized to chromosome 10 of X. tropicalis, whereas AR and SF-1/Ad4BP are mapped to chromosome 14 and Sox3 to chromosome 11 in X. laevis. These results suggest that the W sex chromosome was independently acquired in the lineage of X. laevis, and the origins of the ZW sex chromosomes are different between X. laevis and R. rugosa. Cyp17, Cyp19, Dmrt1, Sox9, and WT1 were localized to autosomes in X. laevis and R. rugosa, suggesting that these five genes probably are not candidates for the sex-determining genes in the two anuran species.

Diurnal expressions of four subtypes of melatonin receptor genes in the optic tectum and retina of goldfish.

Four subtypes of melatonin receptor genes (Mel(1a) 1.4, Mel(1a) 1.7, Mel(1b), and Mel(1c)) are considered to be expressed to mediate various physiological functions of melatonin in goldfish (Carassius auratus). To examine their tissue distribution and diurnal changes in expression levels, we cloned partial gene fragments for these melatonin receptor subtypes, and established specific RT-PCR and quantitative real-time PCR systems. Mel(1a) 1.4 and Mel(1b) were predominantly expressed in various neuronal and peripheral tissues, while Mel(1a) 1.7 and Mel(1c) were expressed in the restricted tissues. All subtype genes were expressed in the optic tectum, diencephalon, mesencephalon, vagal lobe, retina and spleen. The real-time PCR analyses showed that significant differences among time were observed for Mel(1a) 1.4 in the optic tectum and for Mel(1a) 1.7 and Mel(1b) in the retina. In the retina, the levels of Mel(1a) 1.7 and Mel(1b) mRNAs showed diurnal changes with one peak at ZT24. The present results show differential distribution of four subtypes of melatonin receptor mRNAs in the neuronal and peripheral tissues. However, the expressions of all subtype genes in the retinorecipient brain regions and retina reinforce the role of the melatonin receptor in processing visual information. Furthermore, the present study demonstrates diurnal expressions of the major subtype genes, i.e. Mel(1a) 1.4 in the optic tectum and Mel(1a) 1.7 in the retina.

Immunohistochemical detection and biological activities of CYP17 (P450c17) in the indifferent gonad of the frog Rana rugosa.

Sex steroids play a crucial role in the gonad differentiation in various species of vertebrates. However, little is known regarding the localization and biological activity of steroid-metabolizing enzymes during gonadal sex differentiation in amphibians. In the present study, we showed by real-time RT-PCR analysis that the expression of CYP17, one of the key steroidogenic enzymes, was higher in the indifferent gonad during sex differentiation in male than in female tadpoles of Rana rugosa but that there was no difference detected in the 3betaHSD mRNA level between the male and female gonads. We next examined the localization of CYP17, 3betaHSD and 17betaHSD in the indifferent and differentiating gonads by using three kinds of antibodies specific for CYP17, 3betaHSD and 17betaHSD, respectively. Positive signals for CYP17, 3betaHSD and 17betaHSD were observed in somatic cells of the indifferent gonad of males and in the interstitial cell of the testis. The enzymatic activity of CYP17 was also examined in the gonad during sex differentiation in this species. [(3)H]Progesterone (Prog) was converted to [(3)H]androstenedione (AE) in the indifferent gonad in males and females, but the rate of its conversion was higher in males than in females. Moreover, fluorescence in situ hybridization (FISH) analysis revealed that the CYP17 gene was located on the q arm of chromosome 9, indicating that CYP17 was autosomal in R. rugosa. Taken together, the results demonstrate that the CYP17 protein is synthesized in somatic cells of the indifferent gonad during gonadal sex differentiation in R. rugosa and that it is more active in converting Prog to AE in males than in females. The data suggest that CYP17 may be involved in testicular formation during sex differentiation in this species.

Distribution and localization of pituitary adenylate cyclase-activating polypeptide-specific receptor (PAC1R) in the rostral migratory stream of the infant mouse brain.

Pituitary adenylate cyclase-activating polypeptide (PACAP) is known to participate in the regulation of neuronal proliferation and differentiation. While these processes are considered to be mediated via PACAP's actions on the PACAP-specific receptor, PAC1R, the precise distribution of PAC1R during neurodevelopment has not yet to be elucidated in detail. The purpose of this study is to examine the distribution of PAC1R in the neurogenic region of the rostral migratory stream (RMS) from the apical subventricular zone (SVZa) to the olfactory bulb (OB) in infant mice using immunostaining. Co-immunostaining for PAC1R in a variety types of cell were carried out using different markers. These included the neural stem cell markers, nestin and glial fibrillary acidic protein (GFAP), a marker for migrating neuroblasts (doublecortin, DCX), a marker for immature neurons betaIII-tubulin, (Tuj1), and a marker for mature neurons, neuronal nuclei (NeuN). PAC1R-like immunoreactivity (LI) was observed in the RMS. However, the intensity of PAC1R- LI was different depending on the regions which were investigated. PAC1R-LI was strong in nestin- and GFAP-positive cells in the SVZa and was also observed in NeuN-positive cells in the OB. However, the intensities of PAC1R-LI in DCX- and Tuj1-positive cells were weaker than the other markers. These results suggest that PACAP may participate in the neurodevelopment with the stage-specific expression of PAC1R and that PACAP plays important roles in neurons as well as in glial cells.