Differential expression of syntaxin-1 and synaptophysin in the developing and adult human retina

Synaptophysin and syntaxin-1 are membrane proteins that associate with synaptic vesicles and presynaptic active zones at nerve endings, respectively. The former is known to be a good marker of synaptogenesis; this aspect, however, is not clear with syntaxin-1. In this study, the expression of both proteins was examined in the developing human retina and compared with their distribution in postnatal to adult retinas, by immunohistochemistry. In the inner plexiform layer, both were expressed simultaneously at 11-12 weeks of gestation, when synaptogenesis reportedly begins in the central retina. In the outer plexiform layer, however, the immunoreactivities were prominent by 16 weeks of gestation. Their expression in both plexiform layers followed a centre-to-periphery gradient. The immunoreactivities for both proteins were found in the immature photoreceptor, amacrine and ganglion cells; however, synaptophysin was differentially localized in bipolar cells and their axons, and syntaxin was present in some horizontal cells. In postnatal-to-adult retinas, synaptophysin immunoreactivity was prominent in photoreceptor terminals lying in the outer plexiform layer; on the contrary, syntaxin-1 was present in a thin immunoreactive band in this layer. In the inner plexiform layer, however, both were homogeneously distributed. Our study suggests that (i) syntaxin-1 appears in parallel with synapse formation; (ii) synaptogenesis in the human retina might follow a centre-to-periphery gradient; (iii) syntaxin-1 is likely to be absent from ribbon synapses of the outer plexiform layer, but may occur at presynaptic terminals of photoreceptor and horizontal cells, as is apparent from its localization in these cells, which is hitherto unreported for any vertebrate retina

Because

nag_zhpcon (f07puc) nag_zhpcon (f07puc) estimates the condition number of a complex Hermitian indefinite matrix A, where A has been factorized by nag_zhptrf (f07prc), using packed storage

f08 – Least-squares and Eigenvalue Problems (LAPACK) f08wwc

nag_zggbak (f08wwc) nag_zggbak (f08wwc) forms the right or left eigenvectors of the real generalized eigenvalue problem Ax Bx, by backward transformation on the computed eigenvectors given by nag_ztgevc (f08yxc). It is necessary to call this function only if the optional balancing function nag_zggbal (f08wvc) was previously called to balance the matrix pair ðA; BÞ

g12 – Survival Analysis g12zac

nag_surviv_risk_sets (g12zac) nag_surviv_risk_sets (g12zac) creates the risk sets associated with the Cox proportional hazards model for fixed covariates

void nag_open_file (const char *filename, Integer mode, Nag_FileID *fileid,

nag_open_file (x04acc) nag_open_file (x04acc) opens a file for reading, writing or appending, and returns an associated file identifier

f07 – Linear Equations (LAPACK) f07fsc

nag_zpotrs (f07fsc) nag_zpotrs (f07fsc) solves a complex Hermitian positive-definite system of linear equations with multiple right-hand sides, AX B, where A has been factorized by nag_zpotrf (f07frc)