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H J Karten

Publications and source records attributed to H J Karten.

At least 55 records · Page 3Linked to original sources
PubMed1991

GABAA receptors in the retina of the cat: an immunohistochemical study of wholemounts, sections, and dissociated cells.

Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter used by many neurons of the mammalian retina. To identify the synaptic targets of these cells, we undertook an immunohistochemical study with a monoclonal antibody that recognizes the GABAA receptors (62-3G1, generously donated by A. de Blas). This antibody labels the somata of at least one group of amacrine cells in the inner nuclear layer. It also labels two groups of somata in the ganglion cell layer; one small and the other much larger. The small cells are likely to be displaced amacrine cells based on their size, although some could be gamma ganglion cells. The much larger receptor-positive cells are clearly ganglion cells, based both on their size and the antibody labeling of the initial portion of their axon. In the peripheral retina, the size of these large somata suggests that many are beta ganglion cells. However, at any point across the retina the density of these cells never exceeded 50% of the density of beta cells as a whole. The antibody also labels a dense plexus of processes that extends throughout the inner plexiform layer (IPL), with a marked concentration in the inner third of the layer. This is the portion of the IPL in which the rod bipolar cells terminate. It is difficult to recognize processes of individual cells in the IPL, so retinae were dissociated. The rod bipolar cells were identified by protein kinase C immunoreactivity (Negishi et al., 1988; Karschin & Wäsle, 1990). They were not labeled by the GABAA receptor antibody. This is surprising in light of tight-seal, whole cell voltage-clamp recordings that have shown that the rod bipolars express functional GABAA receptors. One possible explanation is that the antibody recognizes only a subset of the GABAA receptors.

Animals↗
PubMed1991

Homology and evolutionary origins of the 'neocortex'.

The telencephalon of mammals is characterized by the presence of a hexalaminated structure on its external surface, with specific auditory, visual, somatosensory and motor regions. Due to its seeming unique presence in mammals, it is frequently designated as the neocortex. The evolutionary origins of the so-called neocortex have long puzzled comparative neuroanatomists, in view of the seeming absence of a neocortical-like anlage in nonmammalian amniotes. The resolution of this puzzle requires analysis of both adult and embryonic brains. Experimental neuroanatomical, physiological and behavioral methods applied to adult avian and reptilian brains have finally clarified several fundamental questions regarding the origins of 'neocortex' and have indicated that these origins can be viewed as consequent to two separate events: (1) The elaboration of constituent neuronal populations and their associated connections that are common to the telencephalae of both nonmammalian and mammalian amniotes. In mammals these populations are found within the so-called neocortex. In birds and reptiles, most of these neurons are found within the dorsal and dorsolateral ventricular ridges (DVR and DLVR). (2) In mammals, the components of the DVR and DLVR are incorporated into the thin overlying pallium to form a laminated 'neocortex'. Analysis of development in domestic chicks suggests that the DVR is one of several prosencephalic neuromeres ('Prosomeres') that contribute to the ontogeny of comparable structures in birds. Perhaps in mammals, as well, cortical development is consequent to incorporation of these several prosomeres into proliferative ependyma of the pallial mantle.

Animals↗
PubMed1990

Immunohistochemical analysis of the visual wulst of the pigeon (Columba livia).

The avian wulst, a laminated "bulge" in the dorsal telencephalon, contains several distinct regions. The posterolateral portion (visual wulst) has been proposed to be an avian equivalent of the mammalian striate cortex. The present study examines specific neurotransmitters and neuropeptides within the visual wulst by immunohistochemical techniques. Antisera and monoclonal antibodies against choline acetyltransferase (ChAT), nicotinic acetylcholine receptor (nAChR), tyrosine hydroxylase (TH), serotonin (5-HT), glutamic acid decarboxylase (GAD), gamma-aminobutyric acid A receptor (GABAAR), cholecystokinin (CCK), substance P (SP), leucine-enkephalin (L-ENK), neurotensin (NT), neuropeptide Y (NPY), somatostatin (SRIF), corticotropin-releasing factor (CRF), and vasoactive intestinal polypeptide (VIP) were used. Somata and neuropil displaying specific immunoreactivity were generally distributed in accordance with the laminar cytoarchitectonic organization of the wulst. The superficial layer of the wulst, the hyperstriatum accessorium, contained the highest densities of TH-, 5-HT-, SP-, NPY-, SRIF-, CRF-, and VIP-positive neuropil in the wulst, whereas the highest density of CCK- and NT-staining was found in the deepest layer of the wulst, the hyperstriatum dorsale. In addition to the traditionally defined four laminae of the wulst, the immunoreactive staining revealed several subregions within each lamina. The most dorsolateral portion of the wulst contained the highest densities of ChAT- and L-ENK-stained fibers in the wulst, as well as moderately dense staining of neuropil for 5-HT-, TH-, SP-, and CCK-like immunoreactivity. The nAChR-immunoreactivity was faint and distributed rather uniformly throughout the wulst. The results suggest that the wulst consists of multiple regional variations within layers comparable to laminar variations found within different cytoarchitectonic areas of the mammalian neocortex.

Animals↗
PubMed1990

Differential effects of axotomy on substance P-containing and nicotinic acetylcholine receptor-containing retinal ganglion cells: time course of degeneration and effects of nerve growth factor.

The time course of degeneration of chick retinal ganglion cells was examined with Nissl stains and immunohistochemical methods for detection of substance P-like immunoreactive and nicotinic acetylcholine receptor immunoreactive neurons. Small lesions were made in the retinae, adjacent to the optic nerve head, and were subsequently sectioned parallel to the vitreal surface, permitting direct comparison of normal and axotomized retinal ganglion cells distal to the site of axon damage. At four and six days after surgery, a large number of degenerating cells with clear cytoplasm and pyknotic nuclei were seen. After eight, 10 and 14 days, many retinal ganglion cells displayed a chromatolytic response with dispersed Nissl granules, eccentric nuclei and the cells appeared crenulated. The number of apparently normal neurons in the ganglion cell layer in the axotomized region was reduced by about 50% six days following surgery, by about 70% on the 10th day and by about 75% on the 17th day. The remaining neurons in the ganglion cell layer were identified as displaced amacrine cells. From day 2 onwards, increased numbers of glial cells were present in the optic fibre, ganglion cell and inner plexiform layers. Many glial cells were enlarged and displayed extensive cytoplasmic processes, while others showed mitotic activity. Somata and proximal dendrites of retinal ganglion cells were intensely stained for substance P-like immunoreactivity at two and four days following surgery. At six, eight and 10 days, staining intensity was markedly reduced though still evident and at 14 and 17 days, substance P-like immunoreactivity had virtually disappeared. The persistence of limited substance P-like immunoreactive ganglion cells 10 days after surgery indicates that these cells have a relatively protracted response to axotomy. Nicotinic acetylcholine receptor-like immunoreactivity in the ganglion cells at two and four days following axotomy was substantially reduced. The majority of faintly stained nicotinic acetylcholine receptor-like immunoreactive ganglion cells, as visualized in counterstained sections, did not exhibit pyknosis in the immediate period following axotomy. Double label studies demonstrated that substance P-like immunoreactive ganglion cells were distinct from the nicotinic acetylcholine receptor-like immunoreactive ganglion cells. In a second set of experiments, nerve growth factor was then placed into the vitreous humor following intra-retinal axotomy. The somata, dendrites and proximal axons of lesioned substance P-like immunoreactive ganglion cells in these retinae were more intensely stained for a longer period of time and appeared more robust than cells from untreated retinae.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1990

Presumptive catecholaminergic ganglion cells in the pigeon retina.

An antiserum directed against tyrosine hydroxylase (TH), the rate-limiting enzyme in the synthesis of dopamine, was used to study the pigeon retina. Labeled cells were observed in both the inner nuclear layer (INL) and ganglion cell layer (GCL). Two populations of TH-immunoreactive neurons were observed in the INL. Some of these cells were 7-10 microns in diameter and gave rise to processes that arborized in three layers of the inner plexiform layer (IPL). These cells appeared similar to the dopaminergic amacrine cells described previously (Marc, 1988). Other labeled cells in the INL were 12-20 microns in diameter and were recognizable as a previously described subpopulation of TH-immunoreactive displaced ganglion cells (Britto et al., 1988). A population of labeled cells was observed in the GCL. Counts of these cells in two retinae revealed 5000 and 7000 cells, respectively. They ranged in size from 8-15 microns in diameter in the central retina and from 8-20 microns in diameter in the peripheral retina. The density of labeled cells was highest in the central retina and red field and lowest in the retinal periphery. The difference in cell size and cell density as a function of eccentricity is characteristic of the total population of ganglion cells in the avian retina (Ehrlich, 1981; Hayes, 1982). Some of the TH-positive cells in the GCL could be classified as ganglion cells for two reasons: (1) The axons of many of the TH-positive cells in the GCL were TH-immunoreactive as well and could be followed to the optic nerve head. (2) The injection of rhodamine-labeled microspheres into the nucleus geniculatus lateralis, pars ventralis (GLv), resulted in the retrograde labeling of many of the TH-positive cells in the contralateral retina.

Animals↗
PubMed1989

Immunohistochemical localization of GABAA receptors in the retina of the new world primate Saimiri sciureus.

A large population of amacrine cells in the retina are thought to use GABA as an inhibitory neurotransmitter in their synaptic interactions within the inner plexiform layer. However, little is known about their synaptic targets; the neurons that express the receptors for GABA have not been clearly identified. Recently, the GABAA receptor has been isolated and antibodies have been raised against it. These antibodies have proven useful for the immunocytochemical localization of the receptor, and two brief reports describing the distribution of GABAA receptor immunoreactivity in the retina have appeared (Richards et al., 1987; Mariani et al., 1987). We used a monoclonal antibody (62-3G1) against the GABAA receptor to study the retina of the New World primate Saimiri sciureus. Labeled somata were found in the inner nuclear layer (INL) and ganglion cell layer (GCL). The staining was confined to what appeared to be the cell's plasmalemma and small cytoplasmic granules. Most of the labeled neurons in the INL had small somata (5-7 microns in diameter) located at the vitreal edge of the layer. They arborized in two laminae (approximately 2 and 4) of inner plexiform layer (IPL). Ventral to the optic disc (2.5 mm) they comprised 29% of the cells present. A few of the labeled neurons appeared to be interplexiform cells or flat bipolar cells, with labeled processes that extended into both the IPL and the inner half of the outer plexiform layer. In the GCL, the labeled somata were among the largest present (13-20 microns in diameter), and 2.5 mm ventral to the optic disc they made up 15% of the cells present. Experiments in which immunoreactive somata were retrogradely labeled following the injection of fluorescent tracers into the optic tract provided a conclusive demonstration that some of the immunoreactive somata were ganglion cells. The antibody often labeled their axons in the optic fiber layer. This suggests that the GABAA receptors are transported anterogradely to the retinal terminal fields. The dendrites of the immunoreactive ganglion cells extended into the 2 laminae of labeled processes in the IPL, and their primary dendritic arbors were, at any given eccentricity, quite similar in appearance. This homogeneity suggests that they comprise a particular subset of the ganglion cells. Sections simultaneously labeled with the monoclonal antibody against the GABAA receptor and antisera against either L-glutamic acid decarboxylase (GAD) or GABA revealed that the GAD/GABA was distributed much more widely in the IPL than the GABAA receptor.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1989

Neurotransmitters, receptors, and neuropeptides in the accessory optic system: an immunohistochemical survey in the pigeon (Columba livia).

Immunohistochemical techniques were used to survey the distribution of several conventional transmitters, receptors, and neuropeptides in the pigeon nucleus of the basal optic root (nBOR), a component of the accessory optic system. Amongst the conventional neurotransmitters/modulators, the most intense labeling of fibers/terminals within the nBOR was obtained with antisera directed against glutamic acid decarboxylase (GAD) and serotonin (5-HT). Moderately dense fiber plexuses were seen to label with antibodies directed against tyrosine hydroxylase (TH) and choline acetyltransferase (ChAT). GAD-like immunoreactivity (GAD-LI) was found in many small and medium-sized perikarya within the nBOR. Some of the medium-sized cells were occasionally positive for ChAT-LI. Cell body and dendritic staining was also commonly seen with the two tested antisera against receptors-anti-GABA-A receptor and anti-nicotinic acetylcholine receptor. The antisera directed against various neuropeptides produced only fiber labeling within the nBOR. The densest fiber plexus staining was observed with antiserum against neuropeptide Y (NPY-LI), while intermediate fiber densities were seen for substance P (SP-LI) and cholecystokinin (CCK-LI). A few varicose fibers were labeled with antisera against neurotensin (NT), leucine-enkephalin (L-ENK), and the vasoactive intestinal polypeptide (VIP). Unilateral enucleation produced an almost complete elimination of TH-LI in the contralateral nBOR. SP-LI and CCK-LI were also decreased after enucleation. No apparent changes were seen for all other substances. These results indicate that a wide variety of chemically-specific systems arborize within the nBOR. Three of the immunohistochemically defined fiber systems (TH-LI, SP-LI, and CCK-LI fibers) were reduced after removal of the retina, which may indicate the presence of these substances in retinal ganglion cells. In contrast, the fibers exhibiting ChAT-LI, GAD-LI, 5-HT-LI, NPY-LI, NT-LI, L-ENK-LI, and VIP-LI appear to be of nonretinal origin. Two different populations of nBOR neurons exhibited GAD-LI and ChAT-LI. However, these two populations together constituted only about 20% of the nBOR neurons.

Animals↗
PubMed1989

Chemically specific retinal ganglion cells collateralize to the pars ventralis of the lateral geniculate nucleus and optic tectum in the pigeon (Columba livia).

Immunohistochemical and retrograde tracing techniques were combined to study the retinal ganglion cells which project to the pars ventralis of the lateral geniculate nucleus (GLv) in the pigeon. Using two different fluorescent tracers, two histochemically-distinct populations of ganglion cells were found to project to both the GLv and the optic tectum. The first population of ganglion cells exhibited tyrosine hydroxylase-like immunoreactivity and represented about 20% of all ganglion cells which were retrogradely labeled from the GLv. The second population of ganglion cells showed substance P-like immunoreactivity and represented about 13% of all ganglion cells projecting to the GLv. These results confirm earlier suggestions that the retinal axons projecting to the GLv also project elsewhere and demonstrate that heterogeneity of retinal ganglion cells transmitters is evident even within a single retino-recipient nucleus such as the GLv.

Animals↗
PubMed1988

Immunohistochemical study of the telencephalon of the spiny dogfish, Squalus acanthias.

The paucity of experimental data and the differences in telencephalic organization between sharks and other jawed vertebrates have complicated telencephalic comparisons. The distribution of neuropeptides has been extremely useful in recognizing and comparing major subdivisions of the telencephalon among vertebrates. Immunohistochemical techniques were therefore used to study the distribution of substance P (SP), leucin-enkephalin (LENK), and serotonin (5HT), as well as tyrosine hydroxylase (TH), an indicator of catecholamines, in the telencephalon of the spiny dogfish. The distribution of SP and LENK provides a clear distinction between pallial and subpallial portions of the telencephalon. Two regions of the ventrolateral telencephalon, area superficialis basalis and area periventricularis ventrolateralis, exhibit histochemical similarities to the pallidal and striatal subdivisions, respectively, of the basal ganglia in amniotes. Lower densities of LENK+ and SP+ perikarya and fibers occur in the medial pallium and the pars centralis of the dorsal pallium. Similar histochemical traits characterize the sensory thalamorecipient telencephalic structures in amniotes. The lateral pallium in dogfishes is distinguished by the presence of large numbers of TH+ neurons with radially oriented processes. The presence of these distinctive cells also in the medial wall of the rostral telencephalon suggests that the lateral pallium has a medial extension that is situated ventral to the medial pallium. Neurons containing TH were widely distributed in the telencephalon of spiny dogfish and were particularly abundant in the dorsal pallium, olfactory pallium, and area superficialis basalis. It is currently unclear whether these TH+ telencephalic neurons are, in fact, catecholaminergic or merely contain a TH-like substance unrelated to catecholamine synthesis.

Animals↗
PubMed1988

Catecholaminergic subpopulation of retinal displaced ganglion cells projects to the accessory optic nucleus in the pigeon (Columba livia).

In birds, displaced ganglion cells (DGCs) constitute the exclusive source of retinal input to the nucleus of the basal optic root (nBOR) of the accessory optic system. Tyrosine-hydroxylase (TH) immunoreactivity was examined in the pigeon retina after injections of rhodamine-labeled microspheres into the nBOR. A population of about 400 DGCs was observed in each case to exhibit both TH immunoreactivity and rhodamine bead fluorescence. This corresponded to about 10-15% of the total number of identified DGCs in each retina. Double-labeled cells were medium- to large-size (12 to 20 microns in the largest axis) and were always located at the border between the inner nuclear and the inner plexiform layers. Their dendrites could be followed horizontally in lamina 1 of the inner plexiform layer for up to 300 microns from the cell body. The distribution of double-labeled DGCs appeared to be mostly peripheral, matching the overall distribution of identified DGCs. Larger DGCs (21-28 microns) were never seen to contain TH immunoreactivity. Examination of brain sections revealed plexuses of thin varicose TH-positive axons in all subdivisions of the nBOR. Unilateral enucleation produced an almost complete elimination of TH immunoreactivity in the contralateral nucleus. Such results suggest the existence of a population of catecholaminergic DGCs projecting into the accessory optic system of the pigeon. They also support the emerging hypothesis concerning the neurotransmitter heterogeneity of ganglion cells in the vertebrate retina.

Animals↗
PubMed1988

Neuroactive peptides as markers of retinal ganglion cell populations that differ in anatomical organization and function.

Recent immunocytochemical studies indicate the existence of several classes of peptide- (PRGC) and catecholamine-containing retinal ganglion cells in anurans, birds, and mammals. Different classes of PRGC project to discrete and seemingly unique layers in the retino-recipient portion of the anuran and avian optic tectum. Peptide-containing retinofugal projections to the frog tectum originate early in development, and are reestablished by some classes of PRGC during regeneration of the optic nerve. These findings indicate that chemically specific, parallel retinofugal pathways presumably subserve different functional aspects of vision in vertebrates. Exciting prospects for research include the correlation of physiologically with immunocytochemically defined classes of retinal ganglion cells, the analysis of the possible role of neuroactive peptides in retinofugal transmission, and the pharmacological manipulation of putative peptidergic retinofugal pathways to analyze their role in visual function.

Animals↗
PubMed1988

Cholinoceptive neurons in the retina of the chick: an immunohistochemical study of the nicotinic acetylcholine receptors.

Monoclonal antibodies directed against nicotinic acetylcholine receptors (nAChRs) were used to identify and characterize cholinoceptive neurons in the chick retina. Two monoclonal antibodies (mAbs), mAb 210 and mAb 270, stained many neurons in both the inner nuclear layer (INL) and ganglion cell layer (GCL). A class of large labeled cells in the inner INL were positioned at the INL/IPL (inner plexiform layer) border and resembled displaced ganglion cells (DGCs). Their identity was confirmed with injections of rhodamine-labeled microspheres into the ventral tectum and nucleus of the basal optic root (nBOR). Four days after the injection, large nAChR-positive neurons in the inner INL were labeled with beads. The distribution of these cells matched that reported for DGCs in the chicken and pigeon (Reiner et al., 1979; Fite et al., 1981). Many smaller cells in the INL also exhibited nAChR immunoreactivity. These cells were not retrogradely labeled after bead injections into retinal recipient areas. Their processes entered IPL where they arborized in a band comprised of the inner leaflet of lamina 1 and all of lamina 2. In some instances, a process continued inward to lamina 4. These neurons were tentatively identified as amacrine cells because of their position and branching pattern. Approximately 12-18% of the cells in the GCL exhibited nAChR immunoreactivity. Many of these cells could be classified as ganglion cells as their axons were also labeled following exposure to nAChR antibodies. Their distribution mirrored that of all ganglion cells with a higher density of cells in the central retina than in the periphery (Ehrlich, 1981). A "double label" technique was used to compare the distribution of nAChR-positive neurons with that of the choline acetyltransferase-positive (ChAT), cholinergic neurons in the chick retina. The two antigens were visualized with two different fluorophores: FITC and RITC. We were unable to find any cells in either the INL or GCL that exhibited both ChAT- and nAChR-like immunoreactivity. The nAChR-positive cells and the ChAT-positive cells both arborized in two bands within the IPL. The patterns were in perfect register in the inner IPL (lamina 4). But, in the outer IPL, the nAChR-positive dendrites were observed in the inner leaflet of lamina 1 and in all of lamina 2 while the ChAT-positive dendrites did not extend into the innermost portion of lamina 2.

Acetylcholine↗
PubMed1987

Distribution of substance P-like immunoreactive retinal ganglion cells and their pattern of termination in the optic tectum of chick (Gallus gallus).

Substance P-like immunoreactive (SP-LI) neurons were identified within the inner nuclear layer and ganglion cell layer of the chick retina. The SP-LI cells in the inner nuclear layer consisted of several subtypes of neurons, differing in soma size and dendritic arborization. In the ganglion cell layer a population of moderately labelled SP-LI neurons was also present. About 6-9 microns in diameter and spaced 50-80 microns apart, they formed a regular array across the entire retina, with a density of about 400 cells/mm2 in the superior temporal retina, declining to less than 100 cells/mm2 in the peripheral retina. The total number of SP-LI cells in the ganglion cell layer was approximately 75,000. Individual axons could be followed toward the optic nerve head. Lesions near the optic nerve head resulted in axotomy of ganglion cells within a limited portion of the retina. Two days of postaxotomy there were numerous SP-LI swellings in the proximal segments of axotomized axons. SP-LI neurons in the axotomized zone were larger, more numerous, and showed increased staining of their processes. Fourteen days following a retinal lesion, there was depletion of all SP-LI cells in the ganglion cell layer within the axotomized zone, but the SP-LI neurons in the inner nuclear layer were not noticeably affected. Following a localized injection of rhodamine-coupled latex beads into the optic tectum, a population of retinal ganglion cells (RGCs) in the contralateral retina was retrogradely labelled. Many of these cells also exhibited SP-like immunoreactivity. Examination of the optic tectum indicated the presence of SP-LI fibres in laminae 2-13 (nomenclature of Cajal: Histologie du Systeme Nerveux. Vol. 2. Paris: Maloine, '11), with immunoreactive terminal regions present mainly in laminae 2-4, 7, and 9-13. SP-LI cell bodies were found predominantly in laminae 10-12 and 13. Fourteen days following a retinal lesion, SP-LI processes and terminals were depleted from laminae 2 and 3. Immunoreactive cells and processes in the remaining laminae of the optic tectum were not noticeably altered. The present report confirms the existence of SP-LI retinal ganglion cells in the chick retina and demonstrates their contribution to lamina specific SP-LI arborization in the optic tectum.

Animals↗
PubMed1987

Catecholaminergic horizontal and amacrine cells in the ferret retina.

Enzymes involved in the synthesis of catecholamines were detected in amacrine and what appeared to be a specific class of horizontal cells in the ferret retina. Antisera directed against the enzymes tyrosine hydroxylase (TH), which converts tyrosine to DOPA, and phenylethanolamine N-methyl-transferase (PNMT), which converts norepinephrine to epinephrine, were used with conventional immunohistochemical techniques. A population of perikarya located at the outer margin of the inner nuclear layer (INL) exhibited TH-like immunoreactivity. The cell bodies were 9-12 micron in diameter and gave rise to stout dendrites that tapered rapidly after emergence from the somata. The processes formed a planar array in the inner half of the outer plexiform layer (OPL) slightly external to the cells of origin. We could not detect any inwardly directed processes. A population of PNMT-positive cells was also observed in the outer tier of cells in the INL. These cells were very similar to those exhibiting TH immunoreactivity. An apparent difference between the 2 populations was that there were areas of intense, somewhat punctate PNMT immunoreactivity in the outer OPL. These were not observed in the TH-stained sections. Examination of horizontal sections showed that each TH-positive cell body gave rise to 4-5 major dendrites that branched to form a roughly circular dendritic field. In the periphery of the retina, an individual cell's dendrites encompassed an area up to 170 micron in diameter. The dendritic fields of cells near the center of the retina were substantially smaller.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Retinal neurochemistry of three elasmobranch species: an immunohistochemical approach.

We surveyed retinas of Raja erinacea, Mustelus canis, and Squalus acanthias for neurotransmitter substances by using antisera directed against the substances themselves or against their synthesizing enzymes. Both the peroxidase-antiperoxidase (PAP) and indirect fluorescent techniques were employed to visualize the primary antisera. In all three species positive results were obtained with antisera directed against tyrosine hydroxylase (TOH), glutamic acid decarboxylase (GAD), serotonin (5-HT), and leucine enkephalin (Lenk). Antisera directed against glucagon, neurotensin, beta-endorphin, vasoactive intestinal peptide, or bombesin failed to show any specific staining. Immunoreactivity was located in amacrine, interplexiform, and horizontal cells as well as in axons of the optic fiber layer. The four antisera labelled different amacrine cell classes, distinguished on the bases of perikaryal morphology and the distribution of cell processes in the inner plexiform layer (IPL). Amacrine cells that labelled with the same marker were seen to have different morphologies in the species studied. Thus, TOH-like immunoreactivity was distributed in layers 1, 3, and 5 of the IPL in Mustelus but only in layers 1 and 3 in Raja retina. GAD-like immunoreactivity was found diffusely over all layers of the IPL in Raja, but in Mustelus it was confined primarily to layers 1, 3, and 5 of the IPL. Lenk- and 5-HT-like immunoreactivities showed similar species variations. Two neurochemical classes of interplexiform cell were identified in this study. In Mustelus GAD-like and Lenk-like immunoreactive interplexiform cells were seen whereas in Raja only GAD-positive interplexiform cells were detected. In squalus no unequivocal demonstration of any interplexiform cell was made with these antisera. The GAD antiserum also labelled a subset of the horizontal cells in the dorsal retina of Raja. TOH and 5-HT-antisera labelled axons in the optic fiber layer of all three species but reactive ganglion cell perikarya were not identified.

Animals↗
PubMed1986

Substance P-containing ganglion cells become progressively less detectable during retinotectal development in the frog Rana pipiens.

Substance P-like immunoreactivity (SPLI) was immunohistochemically analyzed in the retinae and optic tecta of Rana pipiens embryos and tadpoles between stages 25 of Shumway (S25) and XXV of Taylor and Kollros (TKXXV). A population of retinal ganglion cell (RGC) somata display SPLI. The number of labeled cell bodies increases in proportion and staining intensity between S25 and TKX and progressively decreases toward the end of metamorphosis. At TKXXV, only occasional cells in the periphery of the retina displaying SPLI can be observed in the RGC layer, heralding the adult condition, in which SPLI can only be seen rarely in occasional RGCs. An increasing proportion of optic nerve axons display SPLI from S25 through TKXVI, decreasing progressively thereafter toward the end of the larval period. Concurrently, SPLI appears for the first time in the superficial tectal neuropil between TKIII and TKV, with progressively increasing staining intensity and in a discrete lamina previously shown to contain retinofugal terminals in the adult. These observations corroborate inferences from previous studies indicating the existence of populations of peptidergic RGCs that terminate within precisely restricted synaptic loci in the tectum and presumably perform different functional operations in the adult. Previous observations, however, necessitated various experimental manipulations involving injuries to the visual system in order to demonstrate neuroactive peptide-like immunoreactivity in RGCs, thus allowing the possibility of posttraumatic expression of anomalous peptide phenotypes that may not reflect normal features of RGCs. The present study eliminates this variable and provides further evidence of the existence of peptidergic RGCs.

Animals↗
PubMed1986

Immunohistochemical localization of intermediate filament proteins of neuronal and nonneuronal origin in the goldfish optic nerve: specific molecular markers for optic nerve structures.

The predominant proteins (58K) of the intermediate filament complex in the goldfish visual pathway consist of a series of isoelectric variants. Previous biochemical studies have shown that proteins ON1 and ON2 are of neuronal origin, whereas ON3 and ON4 are of nonneuronal origin. Polyclonal antibodies, purified by affinity chromatography, that are specific for ON1 and ON2 or ON3 and ON4 have been used to localize histologically the ON proteins within the normal and crushed optic nerve. Anti-ON1/ON2 antiserum presented a pattern consistent with intraaxonal staining. A nonneuronal staining pattern was observed with anti-ON3/ON4 antiserum. The two patterns were distinct from and complementary to each other. The data suggest that ON3 and ON4 represent a novel glial fibrillary acidic protein. The results are discussed in terms of the function of these proteins in development, plasticity, and regeneration.

Animals↗