Retinal transplants into the anterior chamber of the rat eye

Developing retinas from 13-18-day fetuses and 2-day neonatal Long-Evans rats transplanted into the anterior chamber of adult eyes of the same or different strain (Lewis) survive and differentiate. Light and electron microscopic studies show that the transplants undergo histogenetic differentiation, resulting in the development of neurons and Müller glial cells and formation of nuclear and plexiform layers. Vascular connections develop between the host iris and the retinal transplant. Vessels and nerves, presumably of iridal origin, were seen on the surface of some transplants. Possible manifestations of graft rejection were monitored; signs of tissue rejection in transplants performed in the Long-Evans rats, an outbred strain, were rare and if present they were mild, at least during the survival periods of up to 91 days allowed in these experiments. Transplants into the eyes of Lewis rats were also well tolerated during the survival period. These observations indicate that retinal transplantation to the adult eye of a genetically different host can be successfully achieved and that both embryonic and perinatal retinas are suitable as donor tissue for ocular transplants. The procedure offers ample opportunities for the study of problems related to retinal plasticity.     

Differentiation of neurons containing olfactory marker protein in adult rat olfactory epithelium transplanted to the anterior chamber of the eye

Olfactory marker protein is a cytoplasmic component unique to fully-differentiated olfactory sensory neurons. It has been proposed that expression of this protein occurs only if the neurons make synaptic contact with the central nervous system. In the present experiments, adult olfactory epithelium was transplanted as an autograft to the anterior chamber of the eye. This procedure destroys the mature sensory neurons, which are subsequently replaced by division and differentiation of stem cells. The newly-formed sensory neurons differentiate sufficiently to produce olfactory marker protein, without apparently contacting central nervous tissue.We conclude that contact with the central nervous system is not necessary for expression of olfactory marker protein.     

Induction of GFAP production in human glioma lines grafted into the anterior chamber of the rat eye

Three established glial fibrillary acidic protein (GFAP)-negative cell lines from human gliomas were transplanted to the anterior chamber of the rat eye. Short-term survival was seen with all transplants. The cells expressed GFAP following transplantation. For comparison, 4 GFAP-positive cell lines were transplanted. With grafting of 5000 cells of any of 6 bipolar cell lines, the transplanted cells could be seen to develop multiple, slender processes reminiscent of mature astrocytes. When 50,000 cells were grafted, vascularized cell mats covering the corneae were seen. The induction of GFAP production and the phenotypic changes were interpreted as signs of differentiation induced by the new environment. All transplanted cells were rejected after 8 weeks.     

Effect of estrogens on neuronal development in nuclei of the tractus solitarius transplanted into the anterior chamber of the eye in rats

Laboratory of Experimental Morphology, Institute of Experimental Endocrinology, All-Union Endocrinologic Scientific Center, Academy of Medical Sciences of the USSR, Moscow. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 112, No. 10, pp. 446–447, October, 1991.     

Fine structure of the carotid body of the midterm human fetus

Summary The human fetal carotid body was studied using both histochemical and electron microscopic methods. The glomus cells of a mid term fetal carotid body evidently contain catecholamines. This was demonstrated both by formaldehyder-induced fluorescence of the cells and by the presence of typical dense-cored vesicles (diameter 1430–3200 Å) in the cytoplasm of the chief cells. The glomus cells were densely innervated and the synapses found on their surface were probably cholinergic in type, containing agranular synaptic vesicles measuring 400–700 Å in diameter with a few dense-cored vesicles measuring 900 to 1300 Å. Synapses were not found in any other cell type within the glomus caroticum. The prominent feature of the glomus cell cytoplasm was the presence of the dense-cored vesicles. The density of the vesicular core varied only slightly from cell to cell. There were no perceptible differences in vesicular size between the different cells. The glomus cells were mostly surrounded by the processes of the sustentacular cells, which usually also surrounded the capillary walls. No glomus cells were ever found in direct contact with the capillary wall. The capillaries were wide and very numerous over the restricted area of the organ. They formed sinusoidal loops, probably anastomosing with each other. Finally, the features of the fine structure are discussed, correlating the present findings with our knowledge about the adult functional carotic body.     

Surface structure of nervous tissue grafts developing in the anterior eye chamber of the rat (electron microscopic investigation)

Translated from Arkhiv Anatomii, Gistologii i Émbriologii, Vol. 88, No. 2, pp. 17–23, February, 1985.     

Induction of peroxisome proliferation in hepatocytes transplanted into the anterior chamber of the eye. A model system for the evaluation of xenobiotic-induced effects.

The effect of two hypolipidemic peroxisome proliferators, ciprofibrate and di(2-ethylhexyl)phthalate (DEHP), on hepatocytes transplanted into the anterior chamber of the eye was examined. Young male F-344 rats transplanted with dissociated hepatocytes were fed either a control diet or a diet containing 0.025% ciprofibrate or 2% DEHP. After 4-5 weeks of treatment, all rats were sacrificed and the transplanted liver cells and portions of homotopic liver were processed for light and electron microscopy and for immunofluorescence microscopy. Morphometric analysis of transplanted hepatocytes showed a ninefold and fivefold increase in the volume density of peroxisomes in ciprofibrate and DEHP-fed rats, respectively. Indirect immunofluorescence studies revealed a marked induction of peroxisome-associated enzymes. From these data it is concluded that hepatic peroxisome proliferators cross the blood aqueous humor barrier and the transplanted hepatocytes in the anterior chamber of the eye retain their ability to recognize and respond to peroxisome proliferators.     

Changes in the physiology and fine structure of the taenia of the guinea-pig caecum following transplantation into the anterior eye chamber

1. The taenia of the guinea-pig caecum has been used as a model to study the re-establishment of autonomic innervation following transplantation into the anterior eye chamber. The ultrastructure, the histochemical localization of noradrenaline and acetylcholinesterase and the pharmacology of transmission to the taenia have been examined 1 day to 16 weeks following transplantation. Both ganglion-free strips of the taenia and caecal wall segments including the underlying Auerbach's plexus were used.2. Caecal wall preparations: nerve fibres from intramural ganglion cells retracted during the first 2 days following transplantation, but reappeared in the muscle soon afterwards. Adrenergic nerves from the iris formed terminals about ganglion cells at about 2-4 weeks. Both cholinergic excitatory and non-adrenergic (;purinergic') inhibitory transmission to the muscle was re-established by 2-4 days following transplantation.3. Taenia strip preparations: both adrenergic and cholinergic nerve fibres were demonstrated histochemically in muscle bundles by 2-4 weeks. Non-adrenergic inhibitory and cholinergic transmission was not re-established until 2-4 weeks following transplantation. There was an abnormally dense re-innervation of the muscle by adrenergic nerve fibres by about 8 weeks which is compared with the innervation of aganglionic bowel in Hirschsprung's disease.4. The origin of non-adrenergic inhibitory responses in the transplanted taenia is discussed and the results considered in relation to the re-innervation of transplants of the vas deferens and of intestine during early development.