A brain-tumor model utilizing stereotactic implantation of a permanent cannula.

A tumor model involving stereotactically implanted culture-reared tumor cells is presented. Stainless steel cannulas were stereotactically and permanently implanted into the caudate nucleus of 30 rats. The animals were separated into two groups.

Oxytocin nerve fibers innervate beta-endorphin neurons in the arcuate nucleus of the rat hypothalamus.

Fine, varicose oxytocin-containing nerve fibers have been demonstrated in the hypothalamic arcuate nucleus in rats. Using Phaseolus vulgaris leukoagglutinin as an anterograde tracer, fine neuronal fibers of paraventricular nucleus origin could be seen throughout the arcuate nucleus. Using double immunostaining, oxytocin-immunoreactive varicose fibers were observed around or in the close vicinity of beta-endorphin-immunoreactive neurons.

Dynorphin A-containing neural elements in the nucleus of the solitary tract of the rat. Light and electron microscopic immunohistochemistry.

Distribution of dynorphin A (DyA) immunoreactivity in the nucleus of the solitary tract (NTS) was examined in rats after various surgical transections by light and electron microscopic immunohistochemistry. In colchicine-treated animals DyA immunostained perikarya were seen in each subdivision of the NTS. In intact rats, dense network of immunopositive nerve fibers was localized light microscopically, and synaptic contacts were found between DyA immunopositive structures (axo-axonic, axo-dendritic synapses), electron microscopically.

Neuropeptide Y innervation of ACTH-immunoreactive neurons in the arcuate nucleus of rats: a correlated light and electron microscopic double immunolabeling study.

A fairly high number of neuropeptide Y (NPY) and adrenocorticotropic hormone (ACTH) immunoreactive (ir) neuronal perikarya and dense networks of NPY-ir fibers are present in the hypothalamic arcuate nucleus of rats. Light and electron microscopic double immunolabeling techniques were used to demonstrate morphological connections between NPY-ir nerve fibers and ACTH-ir neurons here. Silver-gold intensified diaminobenzidine (DAB) labeling of perikaryal-dendritic immunoreactivity followed by a second, non-intensified DAB chromogen labeling of immunoreactive nerve terminals was used and recommended in the above sequence as a method of choice for the detection of synaptic contacts with double-labeling technique.