Biomedical subjects

A Reiner

Publications and source records attributed to A Reiner.

At least 19 recordsLinked to original sources

PubMed1992

Expression of p43 in breast cancer tissue, correlation with prognostic parameters.

Placental isoferritin (PLF) and its unique superheavy chain p43 have been recently described as being synthesized by breast cancer cell lines but not by normal breast epithelial cells. Since previous reports have demonstrated a correlation between the content of 'normal' ferritin in breast cancer tissue and the degree of differentiation and prognosis, we have determined p43 in the cytosol of 122 breast cancer samples by use of the new monoclonal antibody CM-H-9. The synthesis of p43 showed a significantly negative correlation with tumor size (P = 0.0001), histologic grading (P = 0.0038), nuclear pleomorphism (P = 0.0019), rate of mitosis (P = 0.0002), lymphocytic reaction (P = 0.0001) and a significantly direct correlation with estrogen receptor status (P = 0.0009). Although patients with a higher p43 content showed a trend for a better outcome (median follow-up: 61.4 months), an independent influence of the cytosolic p43 content on survival could not be confirmed by a multiple Cox model. Therefore it seems that p43's prognostic impact is linked to the highly significant correlation with features of differentiation although a statistical bias in the Cox model due to the limited number of patients must also be taken into account. On the other hand, the significant correlation of p43 expression with factors for good prognosis was striking and consistent and warrants further research of this tumor product.

Breast Neoplasms↗

PubMed1992

An immunohistochemical study of the telencephalon of the senegal bichir (Polypterus senegalus).

The telencephalon in ray-finned fish (actinopterygians) is everted, in contrast to the evaginated telencephalic hemispheres in all other vertebrates. In the more derived ray-finned fish, the teleosts, proliferation of neurons and their migration from the ependymal zone of the pallium renders comparisons between telencephalic cell groups of the teleosts and members of other vertebrate groups extremely difficult. The telencephalon of Polypterus (a primitive living ray-finned fish), although everted, is cytoarchitecturally much simpler than that of teleosts. We have thus applied immunohistochemical techniques to the study of the telencephalon of Polypterus to help clarify the evolution of the telencephalon in teleosts and facilitate comparisons between the telencephalon in ray-finned fish and other vertebrates. Antisera against the following neuroactive substances were used: 1) serotonin (5HT), 2) tyrosine hydroxylase (TH), 3) substance P (SP), 4) leucine-enkephalin (ENK), 5) neuropeptide Y (NPY), and 6) the neurotensin-related hexapeptide LANT6. Several features of the labeling patterns obtained suggested that the dorsal and ventral subdivisions of the area ventralis are homologous as a field to the basal ganglia and septum plus other basal telencephalic regions of land vertebrates, sharks and lungfish: 1) an abundance of SP+, NPY+, and ENK+ fibers; 2) an abundance of TH+ fibers, possibly of posterior tubercle/tegmental origin; 3) the presence of an SP+ fiber bundle that appeared to descend from basal telencephalic levels and terminate in the posterior tubercle/tegmentum, which contain TH+ (possibly dopaminergic) neurons; and 4) an abundance of 5HT+ fibers, presumably of posterior tubercle/tegmental origin. It was not possible, however, to recognize distinct pallidal and striatal subdivisions within the area ventralis of Polypterus. The olfactory pallium (P1) was generally poor in most of the substances examined, except for the presence of LANT6+ fibers. The P3 pallial field was conspicuously rich in SP+ and ENK+ fibers throughout its extent, and the caudal and lateral parts of the P2 field were rich in SP+ fibers and ENK+ fibers. Since this is characteristic of the medial pallial and/or dorsomedial pallial walls of the telencephalon in lungfish, sharks, frogs, and reptiles, the P3 field and caudolateral part of the P2 field may be homologous to these portions of the telencephalon in other vertebrates. More rostromedial parts of P2 may correspond to those parts of the pallium in land vertebrates that are in receipt of specific sensory input from the thalamus, since low neuropeptide levels are characteristic of these regions.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1992

Ultrastructural double-labeling demonstrates synaptic contacts between dopaminergic terminals and substance P-containing striatal neurons in pigeons.

Immunohistochemical studies in rats have demonstrated dopaminergic input onto medium spiny neurons of the striatum. Medium spiny neurons, however, are known to consist of two major neuropeptide-specific types, those containing substance P (SP) and those containing enkephalin. Although both of these types have been shown to receive dopaminergic input onto their perikarya and proximal dendrites, the extent to which both types also receive direct dopaminergic input onto distal dendritic shafts or onto dendritic spines is uncertain. In the present study, we used EM immunohistochemical double-label techniques to examine the synaptic organization of dopaminergic input onto SP+ striatal neurons. We examined the striatum of pigeons, in whom SP+ striatal neurons, including their dendritic shafts and spines, can be readily labeled. Antibodies against tyrosine hydroxylase (TH) were used to identify dopaminergic terminals, which were labeled using silver-intensified immunogold. The SP+ neurons were labeled immunohistochemically using diaminobenzidine. We found that dopaminergic terminals make appositions and form symmetric synapses with the perikarya, dendritic shafts and dendritic spines of SP+ neurons. Thus, nigral dopaminergic neurons provide a monosynaptic input onto SP+ striatal neurons in a manner similar to that described for dopaminergic input onto striatal medium spiny neurons in general.

Animals↗

PubMed1992

Preferential loss of striato-external pallidal projection neurons in presymptomatic Huntington's disease.

We have reported previously that striatal projection neurons are differentially affected in the course of Huntington's disease, and in a prior patient report we noted that differential loss of striatal projection neurons occurs also in patients with presymptomatic Huntington's disease. Striatal neurons projecting to the external segment of the globus pallidus or the substantia nigra show evident loss, whereas those projecting to the internal segment of the globus pallidus appear relatively spared at presymptomatic and early stages of symptomatic Huntington's disease. We now report similar findings in a second apparently presymptomatic Huntington's disease allele carrier.

Adult↗

PubMed1992

Placental isoferritin associated p43 antigen correlates with features of high differentiation in breast cancer.

Placental isoferritin (PLF), an acidic isoform of ferritin, and its unique superheavy chain p43 have been recently described to be synthesized by breast cancer cell lines but not by normal breast epithelial cells. Since previous reports have demonstrated a correlation between the content of 'normal' ferritin in breast cancer tissue, degree of differentiation, and prognosis, we have tried to evaluate the correlation of p43 in the cytosol of 122 breast cancer samples with commonly applied prognostic factors and features of proliferation and differentiation. In parallel, we investigated the correlation of p43 expression in MCF-7 and T47-D breast cancer cell lines during proliferation induced by estradiol plus fetal calf serum (assessed by 3H-thymidine incorporation), compared to p43 expression in stationary non-stimulated cell cultures. The levels of p43 in breast cancer cytosols correlated significantly negatively with tumor size (p = 0.0001), histologic grading (p = 0.0038), nuclear pleomorphism (p = 0.0019), rate of mitosis (p = 0.0002), and lymphocytic reaction (p = 0.0001), and significantly directly with the estrogen receptor status (p = 0.0009). Although patients with a higher p43 content showed a trend for a better outcome (median follow-up: 61.4 months), an independent influence of the cytosolic p43 content on survival could not be confirmed by a multivariate Cox model. In accordance with the observed negative correlation of features of differentiation vs. p43 expression, induction of proliferation by estradiol plus FCS added to serum-free tissue culture medium correlated with a decrease of p43 synthesis in both cell lines. Expression of p43 in estrogen and FCS-absent media revealed also a decrease in relation to a low spontaneous proliferation. However, the drop of p43 synthesis was significantly stronger in cell lines with estrogen-stimulated proliferation. Our in vitro and cytosol results confirm recent clinical observations describing an inverse correlation of p43 synthesis with the degree of proliferation and differentiation in breast cancer. However, the pathologic mechanisms leading to this phenomenon as well as the negative correlation with lymphocytic infiltration are still unclear and need to be further elucidated.

Breast Neoplasms↗

PubMed1992

Biotinylated dextran amine as an anterograde tracer for single- and double-labeling studies.

Fluorescent dextran amines have recently been reported to be useful for anterograde pathway tracing. However, fluorescent markers are not always ideal for detailed mapping studies. We therefore evaluated the efficacy of a biotinylated dextran amine (BDA) for anterograde labeling in several different preparations. BDA was visualized with an avidin-biotinylated HRP (ABC) procedure followed by a standard or metal-enhanced diaminobenzidine (DAB) reaction. After iontophoretic injections of BDA into neocortex-like telencephalic regions in pigeons or into visual or somatosensory cortex in rats, there was excellent and abundant labeling of axons and terminals in forebrain, midbrain and hindbrain target areas with 1-week survival times. Large pressure injections of BDA into the avian telencephalon were also found to result in extensive anterograde labeling. We then carried out a series of studies using 2-color DAB double-labeling to determine effective approaches for combining BDA labeling with other labeling methods. Using an isolated embryonic chick spinal cord-hindlimb preparation, we combined BDA labeling with another anterograde labeling method to differentially label two sets of projections. In these studies, sensory neuron and motoneuron projections into the limb from the same segmental level, or motoneuron projections into the limb from two separate segments were differentially labeled by using HRP (visualized first with a blue/black metal-DAB reaction) and BDA (visualized second with a brown DAB reaction). In other double-labeling studies, we combined BDA labeling of axons and terminals with immunohistochemical labeling of neurons. In these experiments, telencephalic neurons in pigeons or rats were labeled immunohistochemically for parvalbumin or substance P (using a brown DAB reaction) and BDA-labeled axons were labeled blue/black (using a metal-intensified DAB reaction). Double-labeling was successful regardless of whether the entire immunohistochemical labeling procedure preceded or followed the BDA labeling procedure. Together, these studies show that BDA is effective for anterograde pathway tracing and can be used in double-label studies with other labeling methods.

3,3'-Diaminobenzidine↗

PubMed1992

DNA ploidy and other results of DNA flow cytometry as prognostic factors in operable breast cancer: 10 year results of a randomised study.

We evaluated breast cancer specimens from 241 patients of a controlled clinical trial by means of DNA flow cytometry. We report the correlations between DNA index (DNI) and fraction of cells in S-phase (SPF) and other prognostic parameters. Both univariately and in a Cox model, the predictive power of these factors is evaluated after a follow-up of more than 10 years. There are strong correlations between DNI and SPF (P = 0.0001) and between flow cytometry parameters and clinical and histopathological factors such as axillary lymph node involvement, tumour size and histological grade. In univariate analysis DNI fails to provide prognostic information, whereas SPF turns out to be able to differentiate between patients at high and low risk for relapse and death (P = 0.002). In the multivariate Cox model, too, SPF is an important prognostic parameter with respect to patient survival (relative risk: +86%), only surpassed by nodal involvement. DNI, however, turns out to be an independent predictor of relapse free survival and distant recurrence free survival. By combination of DNI and SPF, patients can be divided into three prognostic subgroups. We conclude that data from DNA flow cytometry can be of great importance for the decision on the level of aggressiveness of adjuvant therapy for an individual patient and therefore may help to avoid overtreatment and toxicity.

Adult↗

PubMed1992

[Epidermal growth factor receptor in human breast cancer: correlation with steroid receptors, tumor stage, grading and menopausal status].

In this study, correlations between the epidermal growth factor receptor (EGF-R), steroid receptors, and other prognostic parameters (grading, pTNM-status, menopausal status) were analysed in 326 primary breast carcinomas. 19% of the tumour samples were EGF-R positive, 63% were estrogen receptor (ER) and 54% progesteron receptor (PR) positive. Both steroid receptors were positive in 46% of all samples. We found a highly significant inverse correlation between EGF-R and steroid receptors. 88% of the ER positive tumours were EGF-R negative (p less than 5 x 10(-5)), 90% of the PR positive tumours were EGF-R negative (p less than 5 x 10(-5)) and 91% of the ER plus PR positive tumours were ERF-R negative (p less than 1 x 10(-6)). Grading was available in 170 cases. Six (4%) of the carcinomas were highly differentiated (G1), 82 (48%) were classified as G2, and another 82 (48%) were poorly differentiated (G3). A combination of negative ER and positive EGF-R was found more often in the population of G3 tumours. EGF-R was also positively correlated to tumour size. With regard to receptor status, we did not find a correlation with lymph node involvement. The ER correlated negatively (p less than 1.3 x 10(-5) and the EGF-R positively (p less than 0.042) with menopausal status. Thus, EGF-R overexpression seems to be a marker of morphological and functional dedifferentiation which is associated with a loss of steroid dependency and an increase of an autostimulatory-paracrine growth control. These changes seem to be related to poor prognosis.

Breast↗

PubMed1992

Selective functional posterior rhizotomy for treatment of spastic cerebral palsy in children. Review of 50 consecutive cases.

Fifty consecutive children are described with spastic cerebral palsy treated with selective functional lumbar and sacral rhizotomy and followed for a minimum of 6 months. In all patients, spasticity improved postoperatively, but this was not necessarily accompanied by a functional improvement. Eighteen children who could not walk preoperatively were able to do so after rhizotomy. All 17 children who could walk preoperatively could do so following surgery, and in 15, gait was improved. Complications included transient urinary dysfunction in 4 children and sensory loss in 1. The operative procedure evolved with time: the technique of replacement laminotomy was refined; the electrophysiologic basis for selection of nerve rootlets changed after studies of nonspastic controls; smaller percentages of the L3 and L4 roots were sectioned in an attempt to prevent postoperative weakness of quadriceps, and there was a trend in the most recent patients to cut a smaller portion of all the posterior roots.

Adolescent↗

PubMed1992

Studies of the articular cartilage proteoglycan aggrecan in health and osteoarthritis. Evidence for molecular heterogeneity and extensive molecular changes in disease.

Changes in the structure of the proteoglycan aggrecan (PG) of articular cartilage were determined immunochemically by RIA and gel chromatography and related to cartilage degeneration documented histologically by the Mankin grading system. Monoclonal antibodies to glycosaminoglycan epitopes were used. In all cartilages, three chondroitin sulfate (CS)-rich populations of large size were observed in addition to a smaller keratan sulfate (KS)-rich population. In grades 7-13 OA cartilages (phase II), molecules were significantly larger than the equivalent molecules of grades 2-6 (phase I). CS chain lengths remained unchanged. In most OA cartilages, a CS epitope 846 was elevated in content, this being most marked in phase II (mean: fivefold). Loss of uronic acid, KS, and hyaluronic acid were only pronounced in phase II OA because of variations in normal contents. Aggregation of PG was unchanged (50-60%) or reduced in OA cartilages, but molecules bearing epitope 846 exhibited almost complete aggregation in normal cartilages. This study provides evidence for the capacity of OA cartilage to synthesize new aggrecan molecules to replace those damaged and lost by disease-related changes. It also defines two phases of PG change in OA: an early predominantly degenerate phase I followed by a net reparative phase II accompanied by net loss of these molecules.

Aggrecans↗

PubMed1992

Vasoactive intestinal polypeptide-containing nerve fibers are increased in abundance in the choroid of dystrophic RCS rats.

As photoreceptor degeneration progresses in Royal College of Surgeons (RCS) rats, a variety of morphological and physiological alterations occur in the outer retina. Since the choriocapillaris responds to changes in the outer retina in other retinopathies, we examined the possibility that changes in the choroidal vasculature also occur in RCS rats. The choroidal and choriocapillary vessels in RCS and control (RCS-rdy+) rats were examined during the period after which photoreceptor loss and retinal vascular changes had occurred (7-mos to 28-mos). Light microscopic (LM) morphometry and electron microscopic (EM) examination showed no significant differences between these groups in the number, size or morphology of these vessels. However, EM image analysis revealed that nerve fibers and bundles were twice as abundant in the RCS choroid than in the control. Using immunohistochemical techniques at the LM level combined with image analysis we found that vasoactive intestinal polypeptide positive (VIP+) fibers were significantly increased in the RCS choroid compared with control choroid. In contrast, the abundance of immunoreactive fibers labelled for substance P and dopamine beta hydroxylase appeared similar in both the control and RCS choroid. Since VIP is a potent vasodilator, the increased abundance of nerve fibers in the RCS choroid in conjunction with the unaltered number and size of these vessels suggests that choroidal blood flow may be increased. It is uncertain whether this increase is a response to the outer retinal pathology or contributes to it.

Animals↗

PubMed1991

Immunohistochemical localization of DARPP-32 in striatal projection neurons and striatal interneurons: implications for the localization of D1-like dopamine receptors on different types of striatal neurons.

Immunohistochemical double-label techniques were used to study the localization of DARPP-32, a phosphoprotein that is enriched in neurons possessing members of the D1 subfamily of dopamine receptors, in several different types of striatal neurons in the rat basal ganglia. The vast majority (94.1%) of striatonigral projection neurons (the vast majority of which contain substance P), identified by retrograde labeling with fluorogold, were observed to contain DARPP-32. Similarly, the vast majority of striatopallidal projection neurons (87.7%), identified by immunofluorescence labeling for enkephalin (ENK), were found to label for DARPP-32. In contrast, cholinergic and neuropeptide Y-containing striatal interneurons were never observed to contain DARPP-32. These results suggest that essentially all major types of striatal medium spiny projection neurons may possess members of the D1 subfamily of dopamine receptors, but that striatal local circuit neurons do not possess members of the D1 subfamily of receptors.

Animals↗

PubMed1991

Calcitonin-gene related peptide is an evolutionarily conserved marker within the amniote thalamo-telencephalic auditory pathway.

The distribution of neurons and fibers containing calcitonin-gene-related peptide (CGRP) was mapped in the thalamo-telencephalic auditory pathways of four amniote species, rats, pigeons (Columba livia), caiman (Caiman crocodilus), and turtles (Pseudemys scripta). In colchicine-treated turtles and pigeons, numerous CGRP+ perikarya were observed in the auditory relay nucleus of the thalamus (n. reuniens of reptiles, and n. ovoidalis of birds). In pigeons, these neurons were most abundant in the outer circumference of the nucleus and were not observed without colchicine pretreatment. In the telencephalon of turtles, caiman, and pigeons, CGRP+ fibers were observed within portions of the dorsal ventricular ridge previously shown to receive projections from the auditory thalamus, thus implying that the thalamic CGRP+ neurons observed here in fact project to these telencephalic areas. In colchicine treated rats, numerous CGRP+ perikarya were observed along the ventral margin of the medial geniculate nucleus extending into the posterior intralaminar and peripeduncular nuclei, as well as occasionally within the ventral subdivision of the medial geniculate nucleus. Injections of fluorogold into the auditory cortex combined with immunofluorescence labeling for CGRP revealed that CGRP+ cells in these areas do, in fact, project to the auditory cortices. The present results are interpreted as providing strong support for the theory, advanced previously, that the medial geniculate nucleus of mammals, nucleus ovoidalis of birds, and nucleus reuniens of reptiles contain at least some homologous cell populations. Although the data are consistent with the theory that the telencephalic projection fields are homologous, other interpretations are also consistent with the data presented here. These include the possibility that auditory thalamic projections to the telencephalon arose independently in the lines of evolution leading to mammals and sauropsids.

Alligators and Crocodiles↗

PubMed1991

Ultrastructural single- and double-label immunohistochemical studies of substance P-containing terminals and dopaminergic neurons in the substantia nigra in pigeons.

The vast majority of striatonigral projection neurons in pigeons contain substance P (SP), and the vast majority of SP-containing fibers terminating in the substantia nigra arise from neurons in the striatum. To help clarify the role of striatonigral projection neurons, we conducted electron microscopic single- and double-label immunohistochemical studies of SP+ terminals and/or dopaminergic neurons (labeled with either anti-dopamine, DA, or anti-tyrosine hydroxylase, TH) in pigeons to determine: (1) the synaptic organization of SP+ terminals, (2) the synaptic organization of TH+ perikarya and/or dendrites, and (3) the synaptic relationship between SP+ terminals and TH+ neurons in the substantia nigra. Tissue single-labeled for SP revealed numerous SP+ terminals contacting thin unlabeled dendrites in the substantia nigra, but few SP+ terminals were observed contacting perikarya or large-diameter dendrites. SP+ terminals contained round, densely packed, clear vesicles, and often contained one or more dense-core vesicles. Synaptic junctions between SP+ terminals and their targets were more often symmetric (86%) than asymmetric. In tissue single-labeled for DA, we observed few terminals contacting DA+ perikarya, whereas terminals contacting DA+ dendrites were more abundant. Terminals contacting DA+ structures comprised at least four different morphologically distinct types based on the morphology of the clear synaptic vesicles and the type of synaptic junction. One type of terminal contained round clear vesicles and made symmetric synapses, and thus resembled the predominant type of SP+ terminal. The second type contained round clear vesicles and made asymmetric synapses, the third type contained medium-size pleomorphic clear vesicles and made symmetric synapses, and the fourth type contained small pleomorphic clear vesicles and made symmetric synapses. The presence of contacts between SP+ terminals and dopaminergic dendrites in the substantia nigra was directly demonstrated in tissue double-labeled for SP (by the peroxidase-antiperoxidase procedure, or PAP, with diaminobenzidine) and TH (by either the silver-intensified immunogold procedure or the PAP procedure with benzidine dihydrochloride). SP+ terminals commonly contacted thin TH+ dendrites in the substantia nigra, but few SP+ terminals contacted large-diameter TH+ dendrites or perikarya. Synapses between SP+ terminals and TH+ neurons were always symmetric. TH+ dendrites also were contacted by terminals not labeled for SP, which were more abundant than were SP+ terminals. Non-TH+ neurons were also contacted by both SP+ terminals and non-SP+ terminals.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1991

The Edinger-Westphal nucleus: sources of input influencing accommodation, pupilloconstriction, and choroidal blood flow.

This study used neuroanatomical techniques to investigate sources of afferents to the Edinger-Westphal nucleus (EW) of the pigeon. The EW contains the parasympathetic preganglionic neurons that, by way of the oculomotor nerve, project to the ciliary ganglion (Narayanan and Narayanan, '76; Lyman and Mugnaini, '80). The ciliary ganglion, in turn, innervates the internal musculature of the eye; the ciliary body, the iris sphincter muscle, and the smooth muscle of choroidal blood vessels (Marwitt et al., '71; Pilar and Tuttle, '82). In the bird, the neurons in the ciliary ganglion that innervate the iris sphincter muscle and the ciliary body receive input specifically from cells in the lateral EW (EWl), whereas those that innervate choroidal blood vessels receive input from cells in the medial EW (EWm) (Reiner et al., '83). Thus neurons in the EWl mediate pupilloconstriction and accommodation, whereas neurons in the EWm modulate choroidal blood flow. To study the afferents to EW, injections of horseradish peroxidase (HRP) were placed in this nucleus. These injections resulted in labeled cells in the area pretectalis, a retinorecipient pretectal nucleus and the suprachiasmatic nucleus, a retinorecipient hypothalamic nucleus. We have previously identified both these areas as being sources of afferents to EW (Gamlin et al., '82, '84). In addition, these HRP injections into EW resulted in labeled cells in the medial mesencephalic reticular formation (MRF) lateral and ventral to the oculomotor nucleus and in a localized area of the rostral lateral mesencephalic reticular formation (LRF) dorsolateral to nucleus subpretectalis. Injections of tritiated amino acids into the MRF labeled the entire EW, while such injections into the LRF labeled only the lateral EW. Both of these projections were predominantly contralateral. This study has identified the sources of two previously undocumented inputs to the avian EW. Both sources of input, the MRF and rostral LRF, receive afferents from visuomotor areas of the telencephalon and visual structures in the midbrain. The MRF input to EW could have either direct or modulatory influences on pupil diameter, accommodation, and choroidal blood flow. The LRF input to EW could play a role in controlling accommodation and possibly the pupillary near response.

Afferent Pathways↗

PubMed1991

Distribution, laminar location, and morphology of tectal neurons projecting to the isthmo-optic nucleus and the nucleus isthmi, pars parvocellularis in the pigeon (Columba livia) and chick (Gallus domesticus): a retrograde labelling study.

Retrograde transport of Phaseolus vulgaris leucoagglutinin (PHA-L), fluorogold, fast blue, rhodamine labelled microspheres, and horseradish peroxidase (HRP) was employed to study the distribution, laminar location within the optic tectum, and morphology of tectal cells projecting upon the isthmo-optic nucleus (ION) and the nucleus isthmi, pars parvocellularis (Ipc), in the pigeon and chick. Following injections into the ION, all retrograde markers labelled tecto-ION neurons and their dendrites in the ipsilateral tectum. The cells were located within a relatively narrow band at the border between layers 9 and 10 of the stratum griseum et fibrosum superficiale (SGFS). Retrogradely labelled neuronal somata were different in both dendritic branching and shape; however, tecto-ION neurons generally possessed non-spiny radially oriented and multi-branched dendrites. The apical processes extended into the retino-recipient layers (2-7) of the SGFS and basal dendrites extended into layers 12-14 of the SGFS. Positive neuronal somata were observed throughout the rostro-caudal extent of the optic tectum. The average distance between adjacent tecto-ION neurons varied from one region to another. Specifically, retrogradely labelled cells were more numerous in the caudal, lateral, and ventral tectum, and less numerous at rostro-dorsal levels. Approximately 12,000 tecto-ION neurons were labelled within the ipsilateral optic tectum following either PHA-L or fluorescent dye injections. While the regional distribution of tecto-Ipc neurons was not examined, the morphology indicated that the cells had a single radially oriented dendritic process. Therefore, the apical dendrites are more restricted than those of tecto-ION cells. Moreover, the dendrites were spiny and arborized within layers 3, 5, and 9 of the ipsilateral optic tectum. The axon of tecto-Ipc cells arise from the apical process as a shepherd's crook and descend into the deep layers of the optic tectum. These results indicate that 1) tecto-ION and tecto-Ipc neurons are possibly monosynaptically activated by retinal input, 2) tecto-ION neurons are heterogeneous in morphology, and 3) there is a differential distribution of the tecto-ION neurons throughout the rostro-caudal extent of the optic tectum, suggesting a greater representation of the caudo-ventral portion of the optic tectum within the ION. The discussion primarily concerns the organization of the retino-tecto-ION-retinal circuit in light of the distribution and morphology of tecto-ION neurons within the optic tectum.

Animals↗

PubMed1991

Striatonigral projection neurons: a retrograde labeling study of the percentages that contain substance P or enkephalin in pigeons.

Two largely separate populations of neuropeptide-containing striatonigral projection neurons have been distinguished in pigeons, one population whose neurons contain substance P (SP) and dynorphin (DYN) and a second population whose neurons contain enkephalin (ENK) (Reiner, '86a; Anderson and Reiner, '90a). In the present study, we investigated the abundance of these two types of neurons relative to all striatonigral projection neurons by combining retrograde labeling by the fluorescent dye fluorogold with immunofluorescence labeling for SP and ENK. Pigeons received large intranigral injections of fluorogold to retrogradely label the striatonigral projection neurons, and several days later they were treated with colchicine (32 hours before transcardial perfusion). Adjacent series of sections through the basal ganglia were labeled for SP and ENK using immunofluorescence techniques. The tissue was examined using fluorescence microscopy and the percentages of retrogradely labeled neurons containing either SP or ENK were quantified. We found that 85-95% of the fluorogold-labeled striatonigral neurons were SP+, whereas only 1-4% were ENK+. Thus the majority of striatonigral projection neurons in pigeons appear to contain SP, whereas a small percentage contain ENK. Only a small percentage of striatonigral neurons did not contain either. Since striatal projection neurons also contain GABA (Reiner, '86b), the present results suggest that a high percentage of striatonigral projection neurons coexpress SP, DYN and GABA, whereas a small fraction coexpress ENK and GABA. The available data are consistent with the conclusion that this is true in reptilian and mammalian species as well.

Animals↗

PubMed1991

Neurotransmitter organization of the nucleus of Edinger-Westphal and its projection to the avian ciliary ganglion.

Two morphologically distinct types of preganglionic endings are observed in the avian ciliary ganglion: boutonal and cap-like. Boutonal endings synapse on ciliary ganglion neurons (called choroidal neurons) innervating choroidal blood vessels, while cap-like endings synapse on ciliary ganglion neurons (called ciliary neurons) controlling the lens and pupil. Some of both types of preganglionic endings contain the neuropeptides substance P (SP) and/or leucine-enkephalin (LENK). Although both types of preganglionic terminals are also known to be cholinergic, there has been no direct evidence that SP and LENK are found in cholinergic endings in the ciliary ganglion. The present studies in pigeons, which involved the use of single- and double-label immunohistochemical techniques, were undertaken to examine this issue, as well as to (1) determine the relative percentages of the boutonal and cap-like endings that contain SP, LENK, or both SP and LENK; and (2) determine if the two different types of terminals in the ciliary ganglion arise from different subdivisions of the nucleus of Edinger-Westphal (EW). Single- and double-label immunohistochemical studies revealed that all neurons of EW, regardless of whether they contained immunohistochemically detectible amounts of SP or LENK, are cholinergic. In the medial subdivision of EW (EWM), which was found to contain approximately 700 neurons, 20.2% of these neurons were observed to contain both SP and LENK, while 11.6% were observed to contain SP only and 10.7% were observed to contain LENK only. In contrast, in lateral EW (EWL), which was found to contain approximately 500 neurons, 16.2% of the neurons were observed to contain both SP and LENK, while 19.2% of the neurons were observed to contain SP only and 12.6% were observed to contain LENK only. Retrograde-labeling studies involving horseradish peroxidase injections into the ciliary ganglion revealed that EW was the sole source of input to the ciliary ganglion and all, or nearly all, neurons in EW innervate the ciliary ganglion. Immunohistochemical labeling of the ciliary ganglion neurons with an antiserum against choline acetyltransferase revealed that approximately 900 choroidal neurons and approximately 600 ciliary neurons are present in the ganglion, all of which receive cholinergic preganglionic endings. Of the choroidal neurons, 94% receive butonal terminals containing both SP and LENK, while only 2% receive SP+ only boutonal endings and 2% receive LENK+ only butonal endings. Of the ciliary neurons, 25% receive cap-like endings containing both SP and LENK, 30% receive cap-like endings containing only SP and 3% receive cap-like endings containing only LENK.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗