Serotonergic axons from the raphe nuclei in the brainstem project to every region of the brain, where they make connections through their extensive terminal arborizations. This serotonergic innervation contributes to various normal behaviors and psychiatric disorders. The protocadherin-␣ (Pcdha) family of clustered protocadherins consists of 14 cadherin-related molecules generated from a single gene cluster. We found that the Pcdhas were strongly expressed in the serotonergic neurons. To elucidate their roles, we examined serotonergic fibers in a mouse mutant (Pcdha ⌬CR/⌬CR ) lacking the Pcdha cytoplasmic region-encoding exons, which are common to the gene cluster. In the first week after birth, the distribution pattern of serotonergic fibers in Pcdha ⌬CR/⌬CR mice was similar to wild-type, but by 3 weeks of age, when the serotonergic axonal termini complete their arborizations, the distribution of the projections was abnormal. In some target regions, notably the globus pallidus and substantia nigra, the normally even distribution of serotonin axonal terminals was, in the mutants, dense at the periphery of each region, but sparse in the center. In the stratum lacunosum-moleculare of the hippocampus, the mutants showed denser serotonergic innervation than in wild-type, and in the dentate gyrus of the hippocampus and the caudateputamen, the innervation was sparser. Together, the abnormalities suggested that Pcdha proteins are important in the late-stage maturation of serotonergic projections. Further examination of alternatively spliced exons encoding the cytoplasmic tail showed that the A-type (but not the B-type) cytoplasmic tail was essential for the normal development of serotonergic projections.

Urinary bladder smooth muscle is innervated by both sympathetic and parasympathetic nerves. Acetylcholine released from postganglionic parasympathetic nerve terminals activates postjunctional muscarinic receptors in urinary bladder, which modulate urinary bladder contraction during the voiding phase and control detrusor tone during the filling phase. Five muscarinic receptor subtypes (M 1 -M 5 ) have been identified by both molecular biological and pharmacological investigations.1) The urinary bladder smooth muscle contains a mixed population of muscarinic M 2 and M 3 receptors.2) Although muscarinic M 2 receptors are numerically predominant, muscarinic M 3 receptors are considered to predominate in the mediation of bladder contraction.3,4) An important functional role of the muscarinic M 3 receptor in mediating bladder contraction has also been suggested in experiments using mutant mice lacking the muscarinic M 3 receptor gene. 5)Overactive bladder is characterized by symptoms of urgency and urinary frequency with or without urge incontinence. It has a profoundly negative effect on the quality of life of those affected. Muscarinic receptor antagonists are the most widely used therapy for overactive bladder.6-8) Solifenacin succinate [YM905; (3R)-1-azabicyclo[2.2.2]oct-3-yl(1S)-1-phenyl-3,4-dihydroisoquinoline-2(1H)-carboxylate monosuccinate] is a new muscarinic receptor antagonist developed for the treatment of overactive bladder. Affinity constants (K i values) of this drug for human muscarinic M 1 , M 2 and M 3 receptors only have been reported, along with its antagonism of the contractile effect of carbachol in isolated guinea pig urinary bladder.9) The present study was therefore undertaken to investigate the affinity of solifenacin for all human muscarinic receptor subtypes (M 1 -M 5 ) and its functional muscarinic M 3 receptor antagonism in rats, and to compare the results with those for tolterodine, oxybutynin, darifenacin, propiverine and atropine. Additionally, we also investigated the effect of solifenacin on voiding function in anesthetized rats. MATERIALS AND METHODS MaterialsSolifenacin succinate (YM905, Vesicare ® ), tolterodine tartrate, darifenacin and propiverine hydrochloride were prepared by Astellas Pharma Inc. (Tokyo, Japan). Oxybutynin chloride, atropine sulfate and carbachol (carbamylcholine chloride) were purchased from Sigma-Aldrich (St. Louis, MO, U.S.A.). Darifenacin was dissolved in dimethyl sulfoxide and the others were dissolved in dimethyl sulfoxide, Krebs-Henseleit solution or physiological saline.Animals Male Wistar rats and male Sprague-Dawley rats were purchased from Charles River Laboratories Japan (Kanagawa, Japan) and Japan SLC (Shizuoka, Japan), respectively. In in vitro studies, rats were sacrificed by exsanguination under ether anesthesia. All animal experiments were performed in compliance with the regulations of the Institutional Animal Ethical Committee of Astellas Pharma Inc.Radioligand Receptor Binding Assay Membranes of Chinese hamster ovary (CHO)-K1 cells expressi...

Although use of dynamic MR imaging contributes little in predicting malignancy in head and neck lesions, it can limit the differential diagnosis and has potential in predicting vascularity and recurrence.

The clustered protocadherin-␣ (Pcdha) genes, which are expressed in the vertebrate brain, encode diverse membrane proteins whose functions are involved in axonal projection and in learning and memory. The Pcdha cluster consists of 14 tandemly arranged genes (Pcdha1-Pcdha12, Pcdhac1, and Pcdhac2, from 5 to 3). Each first exon (the variable exons) is transcribed from its own promoter, and spliced to the constant exons, which are common to all the Pcdha genes. Cerebellar Purkinje cells show dual expression patterns for Pcdha. In individual Purkinje cells, different sets of the 5 genes in the cluster, Pcdha1-12, are randomly expressed, whereas both 3 genes, Pcdhac1 and Pcdhac2, are expressed constitutively. To elucidate the relationship between the genomic structure of the Pcdha cluster and their expression in Purkinje cells, we deleted or duplicated multiple variable exons and analyzed the expression of Pcdha genes in the mouse brain. In all mutant mice, transcript levels of the constant exons and the dual expression patterns were maintained. In the deletion mutants, the missing genes were flexibly compensated by the remaining variable exons. On the other hand, in duplication mutants, the levels of the duplicated genes were trimmed. These results indicate that the Pcdha genes are comprehensively regulated as a cluster unit, and that the regulators that randomly and constitutively drive Pcdha gene expression are intact in the deleted or duplicated mutant alleles. These dual regulatory mechanisms may play important roles in the diversity and fundamental functions of neurons.

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