Pigeons homing: Some experiments for testing the olfactory hypothesis

Summary Homing experiments on Swiss pigeons show that the birds use olfactory cues for navigational purposes and that outward journey detours influence their initial orientation.This work was supported by the Consiglio Nazionale delle Ricerche and by the Swiss National Foundation for Scientific Research.     

Immunocytochemical localization of neurons containing ACTH 17-39 in the rat brain]

Immunoreactive neurons and fibers were localized in the Rat brain by immunocytochemistry using an anti-ACTH 17-39 antiserum. Neither adrenalectomy nor water deprivation affected intensity of distribution of reaction of labelled neurons whereas colchicine increased labelling of hypothalamic perikarya. These results support the neuronal origin of cerebral ACTH.     

Does tenotomy of skeletal muscle alter Z-line width in older animals?

Summary Results of unilateral achilles tenotomy on older (350–410 g) male rats, showed that the general width of Z-lines in the tenotomized muscles was not significantly altered by this procedure. Streaming of the Z-lines and rod formations was still present, as in younger rats.This investigation was supported in part by NIH grants 1-RO1-NS-14033 and 1-T32-07224.     

Histochemical and ultrastructural modifications of mice endometrium, vagina and pituitary following zeranol treatment

The histochemical and ultrastructural changes produced by zeranol treatment on the endometrium and the gonadotropic FSH cells of the adenohypophysis have been investigated in mice at the prepuberal and virginal stages. Modifications similar to those induced by estrogen treatment were observed. It is concluded that both estrogens and zeranol share the same activity on the tissues examined.     

Coexistence of neoteny and an internal cycle a polystomatid (Monogenea)]

Metapolystoma cachani a parasite of Ptychadena longirostris (Peters) has been discovered in the Ivory coast. Its life cycle is the first to involve both the possibility of an internal cycle in the bladder of the adult Amphibian and a neotenical reproduction on the gills of the Tadpole. This double process is the link between the Monogeneans which are only parasites of aquatic hosts and those which are adapted to terrestrial hosts. Its place is therefore essential in the phylogeny of Polystomatidae.