The cytoarchitecture of the telencephalon of the Comoran coelacanth, Latimeria chalumnae, was analyzed in the context of recent advances in our understanding of telencephalic organization in lungfishes and amphibians, which constitute the sister group to coelacanths. In coelacanths, the telencephalon is divided into pedunculated olfactory bulbs, paired hemispheres, and an unevaginated telenceph...

Neurogenesis was studied in the medial preoptic area of the guinea pig by the method of tritiated thymidine autoradiography. Eight cytoarchitectonic divisions were examined, 4 of which display sexual dimorphism and 4 that do not. Neurogenesis in the nonsexually dimorphic divisions was found to end at embryonic day (E) 27, while in each of the sexually dimorphic divisions neurogenesis continued ...

Male hamsters in which the stria terminalis (ST) had been interrupted either by electrolytic lesions or knife cuts, or normal control males, received iontophoretic injections of horseradish peroxidase in either the bed nucleus of the stria terminalis (BNST) or the medial preoptic-anterior hypothalamic area (MPOAH). Comparison of intact and ST-lesioned brains revealed the existence of a ventral ...

Several pieces of evidence suggest that the noradrenergic afferents in the medial preoptic area produce sleep and hypothermia by acting on alphal adrenergic receptors. On the other hand, in a few studies monitoring body temperature with a rectal probe, preoptic injection of the alphal adrenergic agonist methoxamine produced contradictory changes in body temperature and sleep-wakefulness. Such c...

Chemosensory and hormonal signals, both of which are essential for mating in the male Syrian hamster, are relayed through a distinct forebrain circuit. Immunocytochemistry for tyrosine hydroxylase, a catecholamine biosynthetic enzyme, previously revealed immunoreactive neurons in the anterior and posterior medial amygdaloid nucleus, one of the nuclei within this pathway. In addition, dopamine-i...

Horseradish peroxidase (HRP) was injected into various nuclei of the amygdala in 50 rats. The retrograde axonal transport of HRP showed various connections arising from the hypothalamic nuclei and the basal forebrain. Neurons of the magnocellular preoptic nucleus send out amygdalopetal axons to all amygdaloid nuclei except the lateral nucleus. The amygdalopetal projections emerge from the large...

The guinea pig exhibits sexually dimorphic patterns of cell density and distribution throughout the medial preoptic area, a region that has been shown to be involved in the regulation of sexually differentiated behavioral and endocrinological reproductive functions (Bleier et al., 1982). The most prominent sex differences involve 2 components of the medial preoptic nucleus (MPN), an anteriorly ...

Aromatase is an enzyme that facilitates the conversion of androgens to estrogens and may play a role in mood and mental status. The main theme of this thesis is the imaging of brain aromatase by use of the PET technique. The PET tracer for aromatase, C-labeled vorozole (VOZ) was developed and evaluated by with in vitro and in vivo methods. In vitro experiments using rat brain showed that VOZ wa...

In Wistar rats, reproductive behavior is controlled in a neural circuit of ventral forebrain including the medial amygdala (Me), bed nucleus of the stria terminalis (BNST) and medial preoptic area (MPOA) via perception of social odors. Diabetes Mellitus (DM) is a widespread metabolic disease that affects many organs in a variety of levels. DM can cause central neuropathies such as neuronal apop...

Male rat sexual behavior requires aromatization of testosterone (T) to estradiol (E2) in the medial preoptic area (MPO) where estrogen receptors (ER) exist in two isoforms, ERα and ERβ. We hypothesized that E2 acts through estrogen receptor α (ERα) in the MPO to promote male mating behavior. Four groups of male rats were castrated, administered DHT s.c. and bilateral MPO implants delivering eit...