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Biomedical subjects

R J Walsh

Publications and source records attributed to R J Walsh.

At least 55 records · Page 3Linked to original sources
PubMed1979

Cytology of the arcuate nucleus in newborn male and female rats.

Five coronal levels of the arcuate nuclei in newborn male and female rats were examined with the transmission electron microscope. The nuclei from male and female neonates appear similar in all respects. All levels exhibit a significant population of round to oval cell profiles with large centrally located nuclei and scant cytoplasm which contains predominantly ribosomes, sparse mitochondria, and a few short cisternae of rough endoplasmic reticulum. These organelle-poor cell profiles resemble neuroblasts in other parts of the developing CNS. The arcuate nuclei of neonates also exhibit some cell profiles with the variety and quantity of organelles characteristic of mature neurons in the arcuate nuclei of adult rats. In addition, the neonatal arcuate nuclei show a paucity of synapses with apparent immaturity of those present, and numerous structures identified as growth cones. Definitive macroglia are not present in the arcuate nuclei of newborn rats.

Animals↗
PubMed1978

Prolactin binding sites in the rat brain.

The principles of the competitive-binding assay were used in conjunction with light microscopic radioautography to demonstrate specific prolactin binding sites localized on ependyma of the rat choroid plexus, a previously unknown prolactin target tissue.

Animals↗
PubMed1978

The age of the menopause of Australian women.

The mean age of the menopause by probit analysis in a group of apparently healthy Australian women was 50.4 years. No relationship was found between this value and the age of the menarche or the number of children born or the age at the time of birth of the first child. The mean duration of the menstruating life was 26.3 years with a range of from 17 to 44 years.

Adult↗
PubMed1978

Early postnatal development of ependyma in the third ventricle of male and female rats.

Ependyma in the third ventricle of developing male and female rats (0, 5, and 10 days postpartum) were compared with those of sexually mature male rats by means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). No sexual dimorphism appeared in the developmental group. At all ages the dorsolateral ventricular wall was composed of ciliated ependymal cells, while ependymal cells of the ventrolateral wall exhibited apical microvilli and bleb-like irregularities. While SEM revealed similarities in apical morphology between ependymal cells adult and developing animals, TEM revealed marked differences between these cells. Many ciliated ependymal cells in developing animals resembled those of the adult while other neonatal cell profiles suggested ciliogenesis. Adult male rats exhibited two distinct tanycyte populations. One population, characterized by elaborate intercellular interdigitations and basal processes containing predominantly fine filaments, occurred adjacent to the ventromedial nucleus (VMN). The second population, characterized by less extensive intercellular interdigitations and basal processes containing, primarily microtubules, lined the roof of the lateral recess adjacent to the arcuate nucleus. Many tanycytes at the level of the arcuate nucleus in developing rats resembled closely those of the adult. In contrast, developing ependymal cells at the level of the VMN differed differed from their adult counterparts in that they exhibited little intercellular interdigitation and projected basal processes characterized by an internal framework of microtubules. Similarities in cytology between developing and adult tanycytes of the arcuate region suggest that the adult function of this population may be operative in the early postnatal period. In contrast, the differing cytology between adult and developing tanycytes of the VMN region suggests that the function of these cells is age-dependent.

Animals↗