Exploring aspects of self-reported emotional mental imagery in patients with bipolar disorder.

BACKGROUND AND OBJECTIVES: CBT for patients with bipolar disorder has modest effects. Across disorders, mental imagery has been used to update CBT to increase effectiveness. In order to enhance CBT for bipolar disorder with imagery techniques, research is needed into emotional imagery quality and, related appraisals of imagery and their relationships with mood instability and subsequent behaviour in bipolar disorder. METHODS: Patients with bipolar disorder (n = 106), unipolar depression (n = 51), creative imagery prone participants (n = 53) and participants without a history of a mood disorder (n = 135) completed the Dutch Imagery Survey (DImS), an online imagery survey, adapted from the Imagery Interview, assessing self-reported emotional imagery aspects. Imagery quality, appraisals and their self-perceived effects on emotion and behaviour were compared between groups. As unexpected differences within the bipolar group appeared, these were additionally explored. RESULTS: Imagery appraisals but not imagery quality discriminated between the patient groups and non-patient groups Imagery was perceived as an emotional amplifier in all groups, but this was specifically apparent in bipolar manic and bipolar depressed groups. Only in the bipolar group imagery was experienced to amplify behavioural tendencies. LIMITATIONS: Results need to be replicated using a larger sample of patients with BD who are currently manic or depressed. CONCLUSIONS: Not only quality of imagery, but especially appraisals associated with imagery are differentiating between imagery prone people with and without mood disorder. Imagery amplifies emotion in all groups, but only in those patients with bipolar disorder currently manic or depressed did this influence behaviour.

Comparing the effectiveness of imagery focussed cognitive therapy to group psychoeducation for patients with bipolar disorder: A randomised trial.

BACKGROUND: Bipolar disorder is a severe, chronic mental disorder. Treatment options are limited, with pharmacological approaches continuing to dominate. However, relapse rates remain high. Several adjunctive psychosocial interventions, mostly psychoeducation (PE) and cognitive behavioural therapy (CBT), have been trialled, but treatment innovation is still needed. In the past, brief group PE has proven as beneficial as longer individual CBT in reducing levels of depression and increasing self-management strategies. We compared the relative effectiveness of group PE to an imagery focussed cognitive behavioural therapy (ImCT). STUDY DESIGN: This was a randomised parallel group study with both daily and weekly measures. A total of 62 adult patients were randomly allocated to either ImCT or group PE. Daily, weekly and pre-and post-intervention measures were used to assess impact on (i) mood instability, (ii) overall levels of depression, anxiety and mania, and (iii) general functioning, hopelessness and imagery characteristics. A four-week baseline and 16-week follow-up period were included. RESULTS: Mood instability reduced in both conditions after intervention. Levels of mania, depression and anxiety also reduced in both conditions, but on the daily measures, depression and anxiety significantly more so in the ImCT condition. Compared with the PE condition, the ImCT condition additionally showed increased level of functioning, reduced hopelessness, and a decrease in intrusive, problematic imagery. LIMITATIONS: These findings need to be replicated in a larger trial. CONCLUSIONS: Findings suggest that ImCT is a promising new avenue for management of bipolar disorder, an area in which treatment development is urgently needed.

Results of TRIO-14, a phase II, multicenter, randomized, placebo-controlled trial of carboplatin-paclitaxel versus carboplatin-paclitaxel-ganitumab in newly diagnosed epithelial ovarian cancer.

PURPOSE: Insulin-like growth factor (IGF) signaling is implicated in pathogenesis and chemotherapy resistance of epithelial ovarian cancer (EOC). We explored efficacy and safety of adding ganitumab, a monoclonal antibody targeting IGF-1R, to carboplatin/paclitaxel (CP) chemotherapy in patients with primary EOC. DESIGN: Patients were randomly assigned to receive CP/ganitumab (18 mg/kg q3w) or CP/placebo for 6 cycles followed by 6 cycles of single agent ganitumab/placebo maintenance therapy as front-line therapy. Primary endpoint was progression free survival. Secondary endpoints were time to progression and overall survival. Pretreatment samples were prospectively collected for retrospective biomarker analyses. RESULTS: 170 patients enrolled. 165 patients assessable for toxicity. Median PFS was 15.7 months with CP/ganitumab and 16.7 months with CP/placebo (HR 1.23; 95% CI 0.82-1.83, P = 0.313). All grade neutropenia (84.1% vs 71.4%), thrombocytopenia (75.3% vs 57.1%) and hyperglycemia (15.9% vs 2.6%) were more common in the ganitumab group compared to the placebo group. Ganitumab/placebo related serious adverse events were reported in 26.1% of the patients with ganitumab and in 6.5% with placebo. Non-progression related fatal events were more common with ganitumab (5 versus 2 patients). The ganitumab group experienced more dose delays which resulted in lower relative dose intensity of chemotherapy in the experimental group. In an exploratory model IGFBP2 expression was predictive of ganitumab response (treatment interaction; PFS, P = 0.03; OS, P = 0.01). CONCLUSION: Addition of ganitumab to CP chemotherapy in primary EOC did not improve PFS. Our results do not support further study of ganitumab in unselected EOC patients.

Image qualities and mood variability: Evaluating the utility of an imagery survey for bipolar disorder.

OBJECTIVE: Imagery appears to play an important role in mood variability, a core symptom of patients suffering from bipolar disorder. The present study aimed to explore the validity and reliability of an online self-report measure of imagery, the Dutch Imagery Survey (DImS). The DImS is an adaptation of the Imagery interview used in research on imagery in mental disorders. The present study additionally explored the ability of the DImS to detect relationships between self-reported imagery and subsequent mood and subsequent behaviour. METHOD: 135 students completed the DImS and additional mental imagery and mood questionnaires. For re-test reliability, 42 students completed the survey again within two days. RESULTS: Internal consistencies and test-retest scores of the five scales of the DImS were reasonable. Imagery Quality correlated with Emotions, and to a lesser degree with Behaviour. Positive Appraisals correlated with Positive Emotions, Negative Appraisals with Negative Emotions, and Positive appraisals with Behaviour. Frequency of Imagery, Imagery Quality and Positive Appraisals correlated with elevated mood. Imagery Quality and Negative Appraisals correlated with low mood. The DImS took approximately 15 min to complete. LIMITATIONS: Re-test reliability was limited due to participants changing their dominant image. Results need to be replicated in a clinical sample. CONCLUSIONS: Psychometric findings with the DImS appeared reasonable and consistent and showed that, in line with other recent studies, imagery is related to current mood and to both self-perceived emotion and subsequent behaviour. These findings suggested that the DImS is suitable to study the role of imagery in bipolar mood variability.

The temporal profile of retinal cell genesis in the marmoset monkey.

The New World marmoset monkey (Callithrix jacchus) has a relatively short gestational period compared with other primates but possesses a retina at a similar stage of maturation by birth. Previous studies have highlighted that the complex fovea of the marmoset undergoes a more rapid postnatal development in comparison with the Macaca monkey, reaching a mature stage earlier than these species. In this current study, we examined the prenatal proliferation profile of cells in the entire retina employing the thymidine analogs and also determined their phenotype by double-label immunocytochemistry using type-specific markers. Akin to other primate species, we demonstrate a centroperipheral gradient in the emergence of both neurons and Müller glia with cones, ganglion cells, and horizontal cells generated first in the fovea at fetal day (Fd)70-74 and with the last generated at the retinal edge at Fd115. Rods, bipolar cells, amacrine cells, displaced amacrine cells, and Müller glia were generated between Fd76 and Fd135 along the same gradient. Similar to foveal development, marmoset neuronal generation was rapid, only taking 51% of gestation whereas in Macaca this takes 81%.

Retrograde transneuronal degeneration in the retina and lateral geniculate nucleus of the V1-lesioned marmoset monkey.

Retrograde transneuronal degeneration (RTD) of retinal ganglion cells and dorsal lateral geniculate (LGN) neurons are well described following a lesion of the primary visual cortex (V1) in both Old World monkeys and humans. Based on previous studies of New World monkeys and prosimians, it was suggested that these species displayed no RTD following a lesion of V1. In this study of the New World marmoset monkey, 1 year after a unilateral V1 lesion either in adults or at 14 days after birth, we observed ~20 % ganglion cell (GC) loss in adult but ~70 % in infants. This finding is similar to the RTD previously described for Old World Macaca monkeys. Furthermore, in infants we find a similar amount of RTD at 3 weeks and 1 year following lesion, demonstrating that RTD is very rapid in neonates. This highlights the importance of trying to prevent the rapid onset of RTD following a lesion of V1 in early life as a strategy for improved functional recovery. Despite differences in GC loss, there was little difference between LGN degeneration in infant versus adult lesions. A wedge on the horizontal meridian corresponding to the LGN foveal representation revealed extensive neuronal loss. Retinal afferent input was labeled by cholera toxin B subunit. Input to the degenerated parvocellular layers was difficult to detect, while input to magnocellular and koniocellular layers was reduced but still apparent. Our demonstration that the New World marmoset monkey shares many of the features of neuroplasticity with Old World Macaca monkeys and humans emphasizes the opportunity and benefit of marmosets as models of visual cortical injury.

The foveal avascular region of developing human retina.

OBJECTIVE: To study the development of the perifoveal retinal vasculature. METHODS: We studied 7 retinas aged between 26 weeks' gestation and 1 week postnatal (41 weeks' gestation). Sections were imaged using high-resolution digital photography and blood vessel profiles identified at 200% to 300% magnification. Flat mounts were immunolabeled using antibodies to CD31 and factor VIII to identify blood vessels and antibodies to rhodopsin to identify the rod-free zone. RESULTS: The foveal region was identified by the absence of rod photoreceptors in the outer retina and/or presence of a shallow depression in the inner retina. The whole mount at 26 weeks' gestation showed a blood vessel-free region centered on the rod-free zone that was open along the horizontal meridian on the temporal side. At 37 weeks' gestation, the foveal avascular zone formed a complete circle. In sections, the foveal avascular zone was approximately 500 microm in diameter at 35 weeks' gestation and 300 to 350 microm at 40 weeks' gestation; in whole mounts, it was 150 to 170 microm in diameter at 37 and 41 weeks' gestation. CONCLUSIONS: The foveal region is normally avascular during development, as in adult life. We found no evidence of foveal vascularization during development of the human retina. Clinical Relevance Instances of vascularization of the foveal region are not due to failed regression of a transient vasculature.

Purkinje cell axon collaterals terminate on Cat-301+ neurons in Macaca monkey cerebellum.

The monoclonal antibody Cat-301 identifies perineuronal nets around specific neuronal types, including those in the cerebellum. This report finds in adult Macaca monkey that basket cells in the deep molecular layer; granule cell layer (GCL) interneurons including Lugaro cells; large neurons in the foliar white matter (WM); and deep cerebellar nuclei (DCN) neurons contain subsets of Cat-301 positive (+) cells. Most Cat-301+ GCL interneurons are glycine+ and all are densely innervated by a meshwork of calbindin+/glutamic acid decarboxylase+ Purkinje cell collaterals and their synapses. DCN and WM Cat-301+ neurons also receive a similar but less dense innervation. Due to the heavy labeling of adjacent Purkinje cell dendrites, the innervation of Cat-301+ basket cells was less certain. These findings suggest that several complex feedback circuits from Purkinje cell to cerebellar interneurons exist in primate cerebellum whose function needs to be investigated. Cat-301 labeling begins postnatally in WM and DCN, but remains sparse until at least 3 months of age. Because the appearance of perineuronal nets is associated with maturation of synaptic circuits, this suggests that the Purkinje cell feedback circuits develop for some time after birth.

Expression patterns of calretinin, calbindin and parvalbumin and their colocalization in neurons during development of Macaca monkey retina.

The developmental expression of calbindin (CalB), calretinin (CaR) and parvalbumin (PV) was followed in Macaca monkey retina using single and double immunolabeling to identify which proteins provide distinctive labels for specific cell types and to clarify the role of these proteins during development. Ganglion cells (GC) expressed PV at fetal day (Fd)55 and CaR and CalB by Fd85. CaR was downregulated after birth. Separate subsets of amacrine (AM) cells expressed CaR and CalB at Fd65-70. After Fd115, many CaR+ AM coexpressed CalB. After Fd120 a few AM expressed PV and these added CaR and CalB after birth. A subset of horizontal cells (HZ) expressed CaR and CalB at Fd70. Slightly later all HZ express PV and CaR while the early subset is CalB+/PV+/CaR+. CaR downregulates in all HZ after birth. The DB3 cone bipolar cells (BP) under the HZ label for CalB by Fd90-110 while a probable OFF BP cell body just above the AM layer becomes CaR+ near birth with labeling increasing after birth. All cones outside of the fovea label for CalB by Fd125. Foveal cones, rods, most BP and Müller glia do not label for these proteins at any age. The complex patterns of up- and down-regulation found in Macaca retina are similar to previous reports of expression in human retina, but in many instances are quite different than earlier reports of CaR, CalB and PV expression patterns in monkey central visual centers. This makes it highly likely that each protein plays a specific but undetermined role(s) in each visual center, and that its expression is controlled at a given stage of retinal development by multiple intrinsic and extrinsic factors.

Co-localization of glycine and gaba immunoreactivity in interneurons in Macaca monkey cerebellar cortex.

Previous work demonstrates that the cerebellum uses glycine as a fast inhibitory neurotransmitter [Ottersen OP, Davanger S, Storm-Mathisen J (1987) Glycine-like immunoreactivity in the cerebellum of rat and Senegalese baboon, Papio papio: a comparison with the distribution of GABA-like immunoreactivity and with [3H]glycine and [3H]GABA uptake. Exp Brain Res 66(1):211-221; Ottersen OP, Storm-Mathisen J, Somogyi P (1988) Colocalization of glycine-like and GABA-like immunoreactivities in Golgi cell terminals in the rat cerebellum: a postembedding light and electron microscopic study. Brain Res 450(1-2):342-353; Dieudonne S (1995) Glycinergic synaptic currents in Golgi cells of the rat cerebellum. Proc Natl Acad Sci U S A 92:1441-1445; Dumoulin A, Triller A, Dieudonne S (2001) IPSC kinetics at identified GABAergic and mixed GABAergic and glycinergic synapses onto cerebellar Golgi cells. J Neurosci 21(16):6045-6057; Dugue GP, Dumoulin A, Triller A, Dieudonne S (2005) Target-dependent use of coreleased inhibitory transmitters at central synapses. J Neurosci 25(28):6490-6498; Zeilhofer HU, Studler B, Arabadzisz D, Schweizer C, Ahmadi S, Layh B, Bosl MR, Fritschy JM (2005) Glycinergic neurons expressing enhanced green fluorescent protein in bacterial artificial chromosome transgenic mice. J Comp Neurol 482(2):123-141]. In the rat cerebellum glycine is not released by itself but is released together with GABA by Lugaro cells onto Golgi cells [Dumoulin A, Triller A, Dieudonne S (2001) IPSC kinetics at identified GABAergic and mixed GABAergic and glycinergic synapses onto cerebellar Golgi cells. J Neurosci 21(16):6045-6057] and by Golgi cells onto unipolar brush and granule cells [Dugue GP, Dumoulin A, Triller A, Dieudonne S (2005) Target-dependent use of coreleased inhibitory transmitters at central synapses. J Neurosci 25(28):6490-6498]. Here we report, from immunolabeling evidence in Macaca cerebellum, that interneurons in the granular cell layer are glycine+ at a density of 120 cells/linear mm. Their morphology indicates that they include Golgi and Lugaro cell types with the majority containing both glycine and GABA or glutamic acid decarboxylase. These data are consistent with the proposal that, as in the rat cerebellum, these granular cell layer interneurons corelease glycine and GABA in the primate cerebellum. The patterns of labeling for glycine and GABA within Golgi and Lugaro cells also indicate that there are biochemical sub-types which are morphologically similar. Further, we find that glycine, GABA and glutamic acid decarboxylase identified candelabrum cells adjacent to the Purkinje cells which is the first time that this interneuron has been reported in primate cerebellar cortex. We propose that candelabrum cells, like the majority of Golgi and Lugaro cells, release both glycine and GABA.

Development of the primate area of high acuity, 3: temporal relationships between pit formation, retinal elongation and cone packing.

By establishing an avascular, highly elastic, region within the fetal area of high acuity (AHA), the developing primate eye has created a unique substrate on which the mechanical forces of intraocular pressure (IOP) and growth-induced retinal stretch (stretch) can act. We proposed (Springer & Hendrickson, 2004b) that these forces generate both the pit and high cone density found in the adult AHA. In this paper, we use quantitative measures to determine the temporal relationships between nasal and temporal retinal elongation, changes in pit depth, cone packing, and cone morphology over M. nemestrina retinal development. Retinal length increased rapidly to about 105 days postconception (dpc; Phase 1) and then elongation virtually ceased (Phase 2) until just after birth (180 dpc). Retinal elongation due to stretch resumed during Phase 3 until approximately 315 dpc (4-5 months), after which time the retina appeared mature (Phase 4). The pit appeared during the quiescent Phase 2, suggesting that IOP acts, in conjunction with molecular changes in the inner retina, on the highly elastic, avascular, AHA to generate a deep, narrow pit and causes inner retinal cellular displacements. Subsequently (Phase 3), the pit widened, became 50% shallower and central inner retinal lamina thinned slightly due to a small amount of retinal stretch occurring in the AHA. Centripetal movement of cones was minimal until just after birth when the pit reached 88% of its maximal depth. Accelerated cone packing during Phase 3 was temporally correlated with increased stretch.

Development of the primate area of high acuity. 1. Use of finite element analysis models to identify mechanical variables affecting pit formation.

Most primate retinas have an area dedicated for high visual acuity called the fovea centralis. Little is known about specific mechanisms that drive development of this complex central retinal specialization. The primate area of high acuity (AHA) is characterized by the presence of a pit that displaces the inner retinal layers. Virtual engineering models were analyzed with finite element analysis (FEA) to identify mechanical mechanisms potentially critical for pit formation. Our hypothesis is that the pit emerges within the AHA because it contains an avascular zone (AZ). The absence of blood vessels makes the tissue within the AZ more elastic and malleable than the surrounding vascularized retina. Models evaluated the contribution to pit formation of varying elasticity ratios between the AZ and surrounding retina, AZ shape, and width. The separate and interactive effects of two mechanical variables, intraocular pressure (IOP) and ocular growth-induced retinal stretch, on pit formation were also evaluated. Either stretch or IOP alone produced a pit when applied to a FEA model having a highly elastic AZ surrounded by a less elastic region. Pit depth and width increased when the elasticity ratio increased, but a pit could not be generated in models lacking differential elasticity. IOP alone produced a deeper pit than did stretch alone and the deepest pit resulted from the combined effects of IOP and stretch. These models predict that the pit in the AHA is formed because an absence of vasculature makes the inner retinal tissue of the AZ very deformable. Once a differential elasticity gradient is established, pit formation can be driven by either IOP or ocular growth-induced retinal stretch.

Development of the primate area of high acuity. 2. Quantitative morphological changes associated with retinal and pars plana growth.

Mechanisms underlying the development of the primate area of high acuity (AHA) remain poorly understood. Finite-element models have identified retinal stretch and intraocular pressure (IOP) as possible mechanical forces that can form a pit (Springer & Hendrickson, 2004). A series of Macaca nemestrina monkey retinas between 68 days postconception (dpc) and adult were used to quantify growth and morphological changes. Retinal and pars plana length, optic disc diameter, disc-pit distance, and inner and outer retinal laminar thickness were measured over development to identify when and where IOP or stretch might operate. Horizontal optic disc diameter increased 500 mum between 115 dpc and 2 months after birth when it reached adult diameter. Disc growth mainly influences the immediate surrounding retina, presumably displacing retinal tissue centrifugally. Pars plana elongation also began at 115 dpc and continued steadily to 3-4 years postnatal, so its influence would be relatively constant over retinal development. Unexpectedly, horizontal retinal length showed nonlinear growth, divided into distinct phases. Retinal length increased rapidly until 115 dpc and then remained unchanged (quiescent phase) between 115-180 dpc. After birth, the retina grew rapidly for 3 months and then very slowly into adulthood. The onset of pit development overlapped the late fetal quiescent phase, suggesting that the major mechanical factor initiating pit formation is IOP, not retinal growth-induced stretch. Developmental changes in the thickness of retinal layers were different for inner and outer retina at many, but not all, of the ten eccentricities examined.

Immunocytochemical characterization of cysts in the peripheral retina and pars plana of the adult primate.

PURPOSE: To better characterize the cellular constituents of cysts in the peripheral retina and pars plana of the adult monkey. METHODS: Frozen sections of the peripheral retinal margin and pars plana from monkeys (Macaca nemestrina) between 1 and 15 years of age were stained with toluidine blue or immunolabeled with a variety of glia- and neuron-specific antibodies. RESULTS: In animals 1 to 2 years of age, the nonpigmented inner layer of the pars plana is a pseudostratified columnar epithelium. In these young animals, the peripheral retina had distinct layers and did not contain cysts. In animals 6 years of age or older, there were numerous cysts in the pars plana and in the peripheral retina. In the peripheral retina, neurons were randomly distributed and did not have a laminar organization. Cells surrounding cysts were immunoreactive for different types of markers for retinal neurons. Some of the cells surrounding cysts in the pars plana were also unexpectedly immunoreactive for antigens normally expressed only in retinal neurons and glia. CONCLUSIONS: Cysts form in the peripheral retina and pars plana in adult monkeys. The peripheral retinal cysts disrupt the normal lamination of the cells, but all types of retinal neurons are still present in the cysts. In an unexpected finding, cysts in the pars plana also contained cells immunoreactive for a few of the markers of retinal cells, suggesting that neurogenesis may occur in the pars plana of the adult primate.

Multiple phosphorylated isoforms of NRL are expressed in rod photoreceptors.

NRL, a bZIP transcription factor of the Maf subfamily, interacts with the homeodomain protein CRX and synergistically regulates rhodopsin expression. Here we report that six isoforms of NRL (29-35 kDa) are generated by phosphorylation and expressed specifically in the mammalian retina. The anti-NRL antibody also cross-reacts with a cytosolic 45-kDa protein, which is detected in neuronal tissues but is not encoded by the NRL gene. In both human retinal cell cultures and sections of fetal and adult human retina, NRL is present in the nuclei of developing and mature rods but not cones. We propose that NRL regulates rod photoreceptor-specific gene expression and is involved in rod differentiation.

Localization of pigment epithelium derived factor (PEDF) in developing and adult human ocular tissues.

PURPOSE: To localize pigment epithelium-derived factor (PEDF) in developing and adult human ocular tissues. METHODS: PEDF was localized in fetal and adult eyes by immunofluorescence with a polyclonal antibody (pAb) against amino acids 327-343 of PEDF, or a monoclonal antibody (mAb) against the C-terminal 155 amino acids of PEDF. Specificity of the antibodies was documented by Western blotting. PEDF mRNA was localized in adult retina by in situ hybridization. RESULTS: In developing retinas (7.4 to 21.5 fetal weeks, Fwks), pAb anti-PEDF labeled retinal pigment epithelium (RPE) granules, developing cones, some neuroblasts and many cells in the ganglion cell layer (GCL). In adult retinas, pAb anti-PEDF labeled rod and cone cytoplasm and nuclei of rods but not cones. Cells in the INL and GCL, choroid, corneal epithelium and endothelium, and ciliary body were also pAb PEDF-positive. Preadsorption of pAb anti-PEDF with the immunizing peptide blocked specific labeling in retina and other tissues, except for photoreceptor outer segments. In agreement with the immunolocalization with pAb anti-PEDF, in situ hybridization revealed PEDF mRNA in the RPE, photoreceptors, inner nuclear layer cells and ganglion cells in adult retina. In developing retinas 18 Fwks and older, and in adult retinas, mAb anti-PEDF labeled the interphotoreceptor matrix (IPM). Western blots of retina, cornea, and ciliary body/iris with pAb anti-PEDF produced several bands at about 46 kDa. With mAb anti-PEDF, retina produced one band at about 46 kDa; cornea and ciliary body/iris had several bands at about 46 kDa. CONCLUSIONS: PEDF, originally reported as a product of RPE cells, is present in photoreceptors and inner retinal cell types in developing and adult human eyes. Photoreceptors and RPE may secrete PEDF into the IPM.

Regulation of retinal capillary cells by basic fibroblast growth factor, vascular endothelial growth factor, and hypoxia.

Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) feature prominently in retinal neovascular diseases. Although the role of VEGF in retinal angiogenesis is well established, the importance of bFGF in this process requires further clarification. This study was undertaken to investigate the responses of retinal capillary cells (endothelial cells and pericytes) to bFGF under hypoxic conditions, as well as the potentially synergistic effects of bFGF and VEGF on the proliferation and cord formation of retinal endothelial cells. Cell proliferation was determined by cell number and by 3H-thymidine incorporation. Cord formation was assessed in three-dimensional gels of collagen type I. VEGF and bFGF increased 3H-thymidine incorporation by both cell types, an effect that was more pronounced in a hypoxic environment. Moreover, the proliferation of pericytes was stimulated to a greater extent by bFGF relative to VEGF. Endothelial migration in collagen gels, however, was induced more effectively by VEGF than by bFGF. A synergistic effect of VEGF and bFGF on cell invasion was observed in the collagen gel assay. VEGF and bFGF each augment proliferation of these cells, especially under hypoxia. We thus propose that these two cytokines have a synergistic effect at several stages of angiogenesis in the retina.

Spatial and temporal expression of short, long/medium, or both opsins in human fetal cones.

Human cone photoreceptors are characterized by long (L), medium (M), or short (S) wavelength-specific opsin. No reports have described the developmental pattern of human cone opsin expression, nor has the existence of human cones containing more than one opsin been tested. Single-and double-label immunocytochemistry and in situ hybridization have been used to determine the developmental pattern of opsin appearance and to investigate the presence of double-labeled cones in sections and wholemounts of human fetal, neonatal, infant, and adult retina. S opsin protein appears in and around the fovea at fetal week (Fwk) 10.9, whereas L/M opsin first appears in the fovea at Fwk 14-15. S opsin mRNA and protein are consistently detected much farther into peripheral retina than L/M opsin, indicating that S appears before L/M opsin. S cones cover 90% of the retina by Fwk 19. L/M cones appear outside the central retina by Fwk 21.5 and reach the retinal edge by Fwk 34-37. The spatial pattern of mRNA expression closely matches that for protein, but mRNA appears slightly earlier than protein at a given retinal point, indicating that only short delays occur between mRNA expression and translation into protein. Cones containing both S and L/M opsin (S+L/M) appear around the fovea shortly after L/M opsin is expressed, are found in more peripheral retina at older ages, and decrease in number after birth. Some S+L/M cones are still detected in adult retina. Both S opsin protein and mRNA appear significantly earlier than L/M mRNA or protein across the human retina, suggesting that the two cone types differentiate under independent controlling factors. However, the presence of single cones containing both S and L/M opsin during development suggests that human cones can respond to the factors controlling expression of each opsin.

Astrocytes and blood vessels define the foveal rim during primate retinal development.

PURPOSE: To investigate the relationship between development of the perifoveal blood vessels and formation of the foveal depression. METHODS: Retinal sections and flatmounts from monkeys aged between fetal day (Fd)80 and 2 years of age were double labeled using antisera to CD31 or von Willebrand factor to detect vascular endothelial cells and antiserum to glial fibrillary acidic protein to detect astrocytes. Sections were studied by fluorescence or confocal microscopy. RESULTS: From Fd88 to 115, vessels on the horizontal meridian were found only at the level of the ganglion cell layer (GCL)-inner plexiform layer (IPL) border where they form the ganglion cell layer plexus (GCP). Stellate astrocytes accompany GCP vessels and extend closer to the fovea than vessels. The foveal avascular zone was present within the GCP at Fd101, and at Fd105 a shallow foveal depression encircled by the GCP was present. The GCP foveal margin had the same dimensions as the adult foveal pit. Both blood vessels and astrocytes were excluded from the emerging fovea throughout development. After Fd140, capillary plexuses in the outer retina anastomosed with the GCP on the foveal slope to form a perifoveal plexus, but this plexus did not mature until a month or more after birth. After Fd142, astrocytes rapidly disappeared from the GCP and most of central retina. CONCLUSIONS: An avascular area is outlined by the GCP before the foveal pit begins to form, suggesting that molecular factors in this region exclude both vessels and astrocytes. These factors may also guide neuronal migration to form the pit. Because the perifoveal plexus is formed during late gestation, both capillary growth and foveal development may be affected adversely by prematurity.

Nocturnal tarsier retina has both short and long/medium-wavelength cones in an unusual topography.

The evolutionary position of tarsiers with respect to primates is still debated. The type of photoreceptors in the nocturnal Tarsius spectrum retina has been compared with the nocturnal New World monkey Aotus trivulgaris and the Old World monkey Macaca nemestrina by using immunocytochemical labeling for antisera known to be specific for primate cone and rod proteins. In all three species, antisera to long/medium (L/M) -wavelength specific cone opsin and cone-specific alpha-transducin detected a single row of cones. Only Macaca and tarsier retina contained cones labeled by antiserum to short (S) -wavelength specific cone opsin. Tarsier rod cell bodies were 6-12 deep, depending on retinal eccentricity. Tarsier central cones had 2-microm-wide outer (OS) and inner segments, which came straight off the cell body. Cone morphology differed little from rods except OS were shorter. Macaca cones labeled for 7G6 and calbindin, Aotus cones did not label for calbindin, and Tarsius cones did not label for 7G6 or calbindin. In tarsier retinal whole-mounts, peak cone density ranged from 11,600-14,200/cones mm(2). The 11- to 12-mm-wide peak region centered roughly on the optic disc, although foveal counts remain to be completed. Density decreased symmetrically to a far peripheral band of 4,200-7, 000/cones mm(2). In contrast, S cone density was very low in central retina (0-300/mm(2)), rose symmetrically with eccentricity, and peaked at 1,100-1,600/mm(2) in a 2- to 3-mm-wide zone in the far periphery. In this zone, S cones were 9-14% of all cones. L/M cones were regularly spaced, whereas S cones showed no regular distribution pattern. Although the functional characteristics of the tarsier S and L/M cone systems are yet to be determined, tarsier cone proteins and distribution have some similarities to both New and Old World monkey retinas.