Receptor Cell Layer Research Articles

Expression of PTPIP51 during mouse eye development

The expression pattern of the novel tyrosine phosphatase interacting protein 51 (PTPIP51) was studied during the organogenesis of mouse eye on a transcriptional (RT-PCR and in situ hybridization) and translational level (immunohistochemistry and immunoblotting). Timed developmental stages from day E12 to day E18 were analyzed regarding the distribution of PTPIP51 and compared to the expression patterns observed during postnatal developmental stages and adult eye. PTPIP51 was found to be expressed in all investigated developmental stages in derivatives of mesoderm and ectoderm, such as developing cornea, lens, neuroretina and extraocular muscles. Conjuctiva and corneal epithelia were PTPIP51 reactive during all investigated developmental stages including the mature eye. Embryonic differentiation led to reactive keratocytes of the corneal stroma and remained so in post partal stages, as well as in the adult eye. On day E12, all cells comprising the developing lens body showed PTPIP51 expression. Further development unto the adult eye resulted in a restriction of PTPIP51 expression to the anterior lens epithelium and finally to the equatorial region of the lens epithelium. The developing neuroretina showed a strong PTPIP51 expression in the inner neuroblastic layer and the future receptor cell layer. In the adult eye, the retinal ganglion cells and the inner nuclear layer remained PTPIP51 reactive. The data presented here suggests PTPIP51 to be integrated in signaling cascades regulating differentiation and apoptosis during eye development.

Neurogenesis and migration of receptor neurons in the vomeronasal sensory epithelium in the opossum, Monodelphis domestica.

The sensory epithelium of the vomeronasal organ (VNO) contains primary chemosensory receptor neurons that project to the accessory olfactory bulb (AOB). In the present study, neurogenesis and cell migration in the sensory epithelium of the VNO were analyzed in opossums (Monodelphis domestica) by using bromodeoxyuridine (BrdU) labeling. 1) In the VNO of normal adult opossums, BrdU labeled a small number of cells localized in the basal region of the sensory epithelium. After 1 or 2 weeks of survival, the labeled cells appeared in the receptor cell layers and became receptor neurons, as indicated by coexpression of the G proteins G(i alpha2) or G(o alpha). 2) In the VNO in which the receptor neurons had been destroyed by removing the AOB, the number of BrdU-labeled cells in the reconstituting sensory epithelium was greatly increased compared with that in the intact VNO. The labeled cells were also located in the basal region of the sensory epithelium. 3) In the developing VNO (at postnatal day 10), more cells in the basal region of the sensory epithelium were labeled than in the adult VNO, indicating rapid cell proliferation; and there appeared to be more labeled cells in the basal region near the margins of the sensory epithelium where it meets the nonsensory epithelium. These observations demonstrate that, in the opossum VNO, there is a population of proliferating cells in the basal region close to the basal lamina in the sensory epithelium. The newly generated neurons in the basal region migrate vertically into the receptor cell layer.

Chloroquine-induced lipidosis in the rat retina: a functional and morphological study.

Corneal opacity, reversible retinal lipidosis and irreversible receptor cell degeneration are known to occur after long-term treatment with chloroquine. Female albino Wistar rats (initial age 6 weeks, weight between 100 and 150 g) were treated orally with chloroquine (40-60 mg/kg body weight) for 4 weeks and with 70-80 mg/kg body weight for the following 4 (group A) and 8 weeks (group B). The animals were submitted to electroretinography ERG, and the retinas were prepared for histological investigation. After treatment with chloroquine for 8 weeks, lipidosis-like inclusions could be seen in the rat retina. A deformation of the receptor cell layer was not observed by light microscopy. The a-wave amplitude decreased to 33% and the b-wave amplitude to 40% of the values before treatment. In contrast to group A, we found receptor cell degeneration and macrophage-like cells in the peripheral and central retina in rats treated for 12 weeks. These changes were probably responsible for a-wave and b-wave reductions of 50 and 79% of values before treatment, respectively. It can be assumed that changes in ERG parameters in the first period are caused by lipidosis. Later extremer deformation is induced by receptor cell degeneration and accompanying lipidosis.

Differential alaserpin expression during development of the antennae in the tobacco hawkmoth, Manduca sexta.

The expression of alaserpin, a serine protease inhibitor, was studied in the developing adult olfactory system of Manduca sexta. Alaserpin mRNA in the antenna was identical to alaserpin from larval fat body, by restriction mapping and partial sequencing of clones isolated from a male pupal stage 6 antennal cDNA library. Northern and primer extension analysis showed that alaserpin transcripts were the same length at all stages and were present at stages 3 and 6, declined at stages 9-15, reappeared at stage 18, and persisted in adults. Western blotting revealed that alaserpin was present at stages 3-12, declined at stage 15, and disappeared at stage 18 and in adults. Immunocytochemistry at stage 6 revealed labeled cells closely associated with neurite bundles and scattered throughout the receptor cell layer. An occasional cell was seen in the antennal lumen. Labeled cells were segmentally distributed along the length of the antenna. The results suggest that alaserpin may have a role in antennal morphogenesis and olfactory neuron axon outgrowth.

Incorporation of 3H‐thymidine in the embryonic vomeronasal and olfactory epithelia of garter snakes

Previous studies have shown that the vomeronasal and olfactory epithelia of adult vertebrates provide good models for studying normal neuronal turnover and regeneration in response to axotomy. However, little is known about the cell dynamics in the embryonic vomeronasal and olfactory epithelia or the origins of different cell types in these structures. By using 3H-thymidine autoradiography, both in vivo and in vitro, the origins of receptor and supporting cells and the survival of labelled cells in the embryonic vomeronasal and olfactory epithelial of garter snakes were examined. The results of this study suggest that the receptor and supporting cells of both epithelial arise from separate stem cells and that two subpopulations of stem cells exist for receptor cells in the embryonic vomeronasal epithelium. One subpopulation generates cells that migrate through the receptor cell columns, while another subpopulation remains at the base of the epithelium for approximately 50 days. Although it is unclear how long receptor cells in the embryonic olfactory epithelium survive, the results of this study suggest that they survive at least 37 days and may survive over 56 days. In addition, the development of these sensory epithelia appears different in early versus late embryos, and regeneration in the vomeronasal and olfactory epithelia of adult garter snakes appears similar to development during late gestation. Cells in the developing receptor cell layer of the olfactory epithelium lose their ability to incorporate 3H-thymidine before those in the vomeronasal epithelium, suggesting that the onset of neuronal maturation occurs earlier in the olfactory epithelium than in the vomeronasal epithelium.

N-acetylhistidine, glutamate, and beta-alanine are concentrated in a receptor cell layer of the trout inner ear.

An epithelial sheet isolated from the trout saccular macula, highly enriched in acousticolateralis receptor cells (hair cells), has been analyzed for primary amine-containing compounds. The hair cell preparation, compared to the saccular nerve, was found to contain elevated levels of the presumptive receptoneural transmitter, glutamate, as well as beta-alanine, and components eluting in the positions of the standards phosphoserine and phosphoethanolamine on cation-exchange HPLC. Saccular nerve contained a different spectrum of primary amines and was elevated specifically in carnosine/homocarnosine. Acid hydrolysis of perchlorate extracts of both hair cell and nerve fractions yielded large amounts of histidine. For the saccular nerve fraction, production of histidine by acid hydrolysis was matched by production of beta-alanine and gamma-aminobutyric acid (GABA) and disappearance of carnosine/homocarnosine. The dipeptides carnosine and homocarnosine have been chromatographically resolved by expanded HPLC and found to be present in saccular nerve in a ratio of approximately 10:1, respectively. Production of histidine in the hair cell extract was not coupled with production of beta-alanine and GABA. The hair cell histidine-containing unknown, present in millimolar concentration, has been identified as N-acetylhistidine by the hydrolysis and rechromatography of fractions from cation-exchange HPLC. The large and specific presence of N-acetylhistidine in the hair cell preparation, together with electrophysiological evidence for its facilitatory action on afferent fibers in the frog semicircular canal, is suggestive of a role for this molecule as well as glutamate in acousticolateralis receptoneural transmission.

Monoclonal antibody immunohistochemistry of adult rabbit olfactory structures

Immunohistochemical staining patterns of two monoclonal antibodies produced against the rabbit olfactory bulb were studied in adult rabbit olfactory structures. One monoclonal antibody 112D5 (monoclonal antibody 2D5) stained all of the olfactory receptor cells, whereas the other 114G12 (monoclonal antibody 4G12) stained the upper two-thirds to three-fourths of the receptor cell layer. The negative region in the receptor cell layer was designated the deep compartment. Neither monoclonal antibody stained the supporting cells, basal cells, or Bowman's glands. Monoclonal antibody 2D5 stained the olfactory nerve layer and glomeruli in the olfactory bulb, whereas monoclonal antibody 4G12 stained the whole of the olfactory bulb, particularly the glomeruli and the mitral cells. The piriform cortex was unstained by monoclonal antibody 2D5 whereas the highest immunoreaction to monoclonal antibody 4G12 was in layer Ia. Immunoblot analysis revealed that the molecular weight values of monoclonal antibody 4G12 antigens in the olfactory epithelium were approx. 26,000. Thus, monoclonal antibody 4G12, specific to neurons, recognized an epitope different from the olfactory marker protein specific to the olfactory receptor neurons.

Monoclonal antibody immunohistochemistry of degenerative and renewal patterns in rabbit olfactory receptor neurons following unilateral olfactory bulbectomy

Degeneration and regeneration of olfactory receptor neurons were studied in adult rabbits by immunohistochemical procedures following unilateral olfactory bulbectomy. Staining patterns of the olfactory receptors of the lesioned side were compared with those of the intact side in the nasal septum at various postoperative periods (12h-6 months) following lesion. Monoclonal antibodies, produced against the rabbit olfactory bulb, were used as histochemical markers. A slight decrease in the number of olfactory receptor neurons occurred at 24 h after lesion. One monoclonal antibody 112D5 stained all receptor neurons including degenerating neurons, but the other 114G12 showed a rapid decrease in immunostaining so that 114G12-positive cells disappeared within 7 days after lesion. 114G12-positive cells reappeared at 4 weeks following lesion. By 3 months, 114G12-positive cells were arranged in a plane at the apical region of the superficial compartment of the receptor cell layer, suggesting a recapitulation of developmental pattern of the receptor neurons. Thereafter, the number of 114G12-positive cells increased progressively and the staining pattern of the olfactory epithelium was like that of control animals by 6 months. Monoclonal antibody 114G12 is thus the first marker that is not specific to olfactory neurons and can be used to characterize certain embryonic traits during the degeneration and regeneration of the olfactory epithelium in the adult mammal.

Monoclonal antibody immunohistochemistry of rabbit olfactory receptor neurons during development

Staining patterns for monoclonal antibodies produced against the rabbit olfactory bulb were studied from embryonic day 14 up to 30 days after birth in the rabbit olfactory receptor neurons. One monoclonal antibody, 112D5, stained all of the receptor neurons in the olfactory epithelium and vomeronasal organ during development. The other, 114G12, showed a unique gradual expression in the olfactory receptor neurons. 114G12-Positive cells first appeared in the epithelium of the embryonic day-17 fetus. At embryonic day 25 or 26, 114G12-positive cells were situated in the superficial receptor cell layer. The arrangement in the positive and negative receptor neurons was ‘superficial-positive’ and ‘deep-negative’. Thereafter, a gradual increase in the number of ‘superficial-positive’ cells was accompanied by a decrease in the ‘deep-negative’ cells. These changes continued until postnatal day 30. The negativity of staining for monoclonal antibody 114G12 in the deep compartment was retained in the adult rabbit. The supporting cells and basal cells were monoclonal antibody 114G12-negative throughout development. This unique developmental pattern suggests that monoclonal antibody 114G12 is a useful probe for studies on neurogenesis in adult animal. In contrast to the olfactory epithelium, the vomeronasal organ was monoclonal antibody 114G12-negative throughout development. Thus monoclonal antibody 114G12 makes a molecular distinction between the olfactory receptor neurons and vomeronasal system.

Hypothyroidism disrupts neural development in the olfactory epithelium of adult mice

Adult mice made hypothyroid with propylthiouracil (PTU) lose their sense of smell. This is prevented by daily administration of thyroxine. As thyroxine is necessary for the correct development of the nervous system it may also be necessary for the genesis of new olfactory receptor neurones, a process that continues into adulthood. Adult mice were treated with PTU, injected with [ 3H]thymidine after 54 days and killed 5 or 15 days later. Microscopic analysis of the olfactory epithelium after autoradiography revealed similar numbers of labelled nuclei in the basal cell layer of the olfactory epithelia of Control and Hypothyroid mice 5 days after injection with [ 3H]thymidine. This indicated similar rates of basal cell division in the two groups. Fifteen days after [ 3H]thymidine injection, however, there were fewer labelled nuclei in the receptor cell layer of Hypothyroid mice and the olfactory epithelium was thinner than in Controls. Thyroxine therapy which reversed PTU-induced anosmia also reversed the epithelial effects of PTU treatment. Somewhat unexpectedly, there were no differences between the treatment groups in the average diameter of glomeruli in the olfactory bulb, and no differences in the expression of olfactory marker protein. The results indicate that although hypothyroidism disrupts neural development in the olfactory epithelium, it does not lead to a complete loss of mature receptor neurones.

Alterations of the retina in chick embryos induced by systemic alpha-bungarotoxin application.

The application of alpha-bungarotoxin onto the chorio-allantoic membrane of chick embryos between the 11th and 18th day of incubation leads to alterations of retinal development. The most significant qualitative change is the appearance of retinal rosettes formed by receptor cells. These rosettes are infoldings of the receptor cell layer. Quantitatively, an enlargement in volume of the receptor and outer nuclear layer can be found together with a simultaneous decrease of the other retinal layers. The toxin seems to suspend the naturally occurring nerve cell death in the receptor cell population

Histochemical evidence for catecholamines as neurotransmitters in the statocyst of Octopus vulgaris.

Formaldehyde-induced fluorescence (Falck-Hillarp technique) provided histochemical evidence for the presence of catecholamines in the sensory epithelia (macula and crista) of the Octopus statocyst. A specific bright green fluorescence occurred in the neuronal plexus beneath the receptor cell layers of the epithelia and in the appropriate nerves. The histochemical findings are discussed with reference to the well-known neuronal and synaptic organization of the epithelia and to relevant results in cephalopods as well as in other molluscs. All data support the hypothesis that in the receptor systems of the Octopus statocyst catecholamines (probably dopamine and/or noradrenaline) act as neurotransmitters in the efferent fibre system.

Spatiotemporal testing and modeling of catfish retinal neurons

The responses of retinal neurons depend on the interaction of both temporal and spatial aspects of a light stimulus. We developed a linear spatiotemporal model of receptor and horizontal cell layers in the catfish retina based on reciprocal interactions between both layers and coupling within each. Horizontal cell transfer properties were measured experimentally using white-noise intensity modulated light spots of different diameters and were compared with analytical predictions based on the model. Good agreement was obtained with a reasonable choice of model space-constants and feedback parameters. Furthermore, the same set of parameter values determined from spot experiments enabled accurate prediction of experimental horizontal cell responses to traveling gratings. The proposed feedback connections from horizontal cells to receptors quicken the time-course of responses in both layers and sharpen receptive fields.

Ruthenium red staining material in Herbst and Grandry sensory corpuscles

The penetration and distribution of ruthenium red into Herbst and Grandry sensory corpuscles has been investigated. Ruthenium red positive substances have been localized in all intercellular spaces including the collagen fibrils, basement membranes and predominately the outer leaflet of the plasmalemmae including the axolemma. Some of the numerous pinocytotic and coated vesicles of the receptor cell layers have been heavily loaded with the dye. Sometimes, the intracytoplasmic and intraaxoplasmic penetration of ruthenium red has been observed. In these cases, the dye deposits have been restricted to the elements of smooth endoplasmic reticulum, mitochondria and microtubules.

Replacement of receptor neurones after section of the vomeronasal nerves in the adult mouse

Eight days after vomeronasal nerve section or removal of the accessory olfactory bulb, the majority of receptor cells of the vomeronasal neuroepithelium degenerate and disappear, leaving a regular framework consisting of supporting cells and their radial processes. The cell clusters at the boundaries of the epithelial sheet (which have been shown to be actively dividing in the normal, unoperated adult mouse) are also spared. The epithelium is subsequently repopulated by receptor cells appearing first in the basal part of the receptor cell layer and later occupying the full width of the receptor layer. These cells are anatomically fully differentiated receptor cells with normal sensory dendrites. Their axons form conspicuous intraepithelial neuromatous masses. Administration of [ 3Hthymidine on days 10–20 postoperatively labels some clusters of supporting cells and virtually all of the receptor cells, indicating that the repopulation of the epithelium is due to new formation of receptor cells.

Ultrastructure of the avian retina an anatomical study of the retina of the domestic pigeon ( Columba liva) with particular reference to the distribution of mitochondria

Ultrastructural, histochemical, and combined histochemical/ultrastructural studies have been made on the retina of the domestic pigeon ( Columba liva). The distributions of mitochondria and of the enzyme succinic dehydrogenase in the retina have been studied. No blood vessels were observed within any of the layers of the retina. Mitochondria were found in the receptor cell layer (rods and cones) where they were numerous only in the region of the ellipsoids, a stratum which formed only 2% of the retinal thickness. Mitochondria were not found in the inner layers of the retina. Succinic dehydrogenase activity was only demonstrated in the receptor cell layer. The biochemistry of the retina and the possible implications of the findings in the understanding of the visual acuity of birds are discussed.

Early cellular disruption and phagocytosis in photically-induced retinal degeneration.

AbstractAlbino rats kept at normal body and room temperature develop a progressive retinal degeneration when exposed to ordinary animal room intensities of fluorescent light. Early changes at the light microscope level include stratification of the inner and outer segments of the receptor cells, followed by rapid fragmentation of these elements. Concurrently, cells not usually seen in control retinas invade the outer plexiform and receptor cell layers. These cells, which are first seen after 60 hours of light exposure, resemble microglia and are apparently phagocytic in function, since cytoplasmic inclusions can be detected. Attempts to mark these cells with intraocular India ink or with intraperitoneal trypan blue were unsuccessful. Removal of cellular debris after degeneration of the receptor cells was followed by gliosis in the area of the retina between the bipolar nuclei and the remnants of the pigment cell layer. The extensive retinal damage occurring after fragmentation and removal of the outer segments was irreversible when animals were removed from continuous light and placed into cyclic lighting.

Localization of the ERG components in the carp retina.

In depth recording studies, the ERG components have usually been localized on the basis of points of maximal amplitude or polarity reversal. However, these criteria are contingent upon definite forms of potential distribution of the ERG. According to an analysis by HASHIMOTO et al.(1961), an alternative criterion based on the point of maximal potential gradient is not so restricted in application.Localization of the ERG components in the carp retina on the basis of the latter criterion revealed that the distal PIII originates in the receptor cell layer whereas both the PII and proximal PIII are generated in the bipolar cell layer. These findings are very similar to data obtained on the frog and turtle eye.

Differentiation of PIII subcomponents in cold-blooded vertebrate retinas

The P III fraction was analysed on isolated inverted retinas obtained from frogs and turtles by means of the coaxial microelectrode. It was found that the conventional P III consisted of at least two subcomponents; the distal P III arising in the receptor cell layer and the proximal P III originating in a more proximal layer. Latency measurements revealed that the onset of the distal P III occured sooner than that of the proximal P III. Furthermore, these two subcomponents differed in resistivity to ammonia vapor. Utilizing the excised opened frog eye, electrode placement between the origins of the distal and proximal P IIIs resulted in a biphasic deflexion prior to the onset of the b-wave. This deflexion was a consequence of differences in latency and polarity between the P III subcomponents.

Subcomponents of P3 in cold-blooded vertebrate retinae.

IT is generally accepted that the PII component of the vertebrate electroretinogram (ERG) arises in the bipolar cell layer. The origin of the PIII component, however, is still the subject of controversy. From experiments on the mammalian retina in situ, Brown and Wiesel1,2 and Brown and Watanabe3 conclude that the receptor cell layer is the origin of PIII, while Tomita4, working on cold-blooded retinae, emphasizes the bipolar cell layer as the main origin of PIII. He observed more recently that, in the excised opened eye of the frog, a small fraction of PIII persists distal to the bipolar cell layer after the abolition of PII and the greater part of PIII by sodium azide. This suggests that PIII is made up of more than one component from different retinal layers4. This suggestion is strongly supported by our depth-recording experiment on isolated inverted retinae of cold-blooded vertebrates. The carp, frog and turtle were used with substantially the same result.