Roles of the gonadal steroid hormones in psychiatric depression in men and women

Dysregulation of neuroendocrine crossroads: depression, circadian rhythms and the retina--a hypothesis

The pathophysiology of depression and the mechanism of action of lithium and other antidepressant drugs involve alterations in circadian rhythms. These include changes in both the intrinsic rhythm of circadian oscillators and in the sensitivity of the retina to LIGHT. The retina in humans is the only photoreceptor for circadian entrainment. The retinal-hypothalamic-pineal axis is the essential pathway for neuronal entrainment of rhythms which use light as a phase cue. A common substance throughout this axis in many species is MELATONIN. Retinal melatonin has been implicated in regulation of the sensitivity of the retina to light. The hypothalamus, at THE NEUROENDOCRINE CROSSROADS, has a central role in the integration of neurotransmitters and hormones in circadian rhythms. DYSREGULATION of the hypothalamic-pituitary-adrenal, as well as -gonadal, axes has been documented in depressed patients. Abnormalities in circulating melatonin have also been found in patients with affective disorders. It is speculated that the availability of melatonin along the retinal-hypothalamic-pineal axis may have important implications in the genesis of affective disorders. More specifically--is there a latent biochemical defect which causes a phase shift and change in circadian rhythms of melatonin and/or other neurotransmitters in the retina which then alters the sensitivity of the retina to light (for the visible spectrum) which in turn desynchronizes all other biological rhythms thus disrupting mental well-being? We suggest that variations of retinal photosensitivity in humans can be measured by using a visual testing system, and that depressed patients might show changes in photosensitivity which could be corrected when treated with lithium and/or antidepressants. It is our working hypothesis that the primary defect in depression may be a change in retinal function, and that behavioural and neuroendocrine concomitants of this disorder are secondary events.

The effects of norethisterone in postmenopausal women on oestrogen replacement therapy: a model for the premenstrual syndrome

The influence of norethisterone on mood and behaviour was investigated in prospective placebo-controlled study in 58 postmenopausal hysterectomized women who were being treated with subcutaneous oestradiol and testosterone implants. Norethisterone, 2.5 or 5 mg daily, was given for 7 days and a placebo for two periods of 7 days. Psychological, behavioural and physical variables were assessed using the Menstrual Distress Questionnaire. There were widespread adverse effects which were dose-related. Significant changes in five of the eight symptom complexes studied (pain, concentration, behavioural change, water retention and negative affect) were found with 5 mg/day of the progestogen. The symptoms were similar to the typical complaints of the premenstrual syndrome, such that a combination of oestradiol and testosterone implants with cyclical oral norethisterone appears to be a model for this condition. The dose of this progestogen should therefore be the minimum to achieve the desired therapeutic effect.

Depressant effect of androgens on the cat brain electrical activity and its antagonism by ruthenium red

Electroencephalographic synchronization and a fall in the multiunit activity was observed in the mesencephalic reticular formation, ventromedial hypothalamus and dorsal hippocampus following intravenous administration of some 5 alpha and 5 beta-reduced testosterone derivatives. The most potent compounds were androsterone and androstanediol which have the 3 alpha-hydroxy-5 alpha ring A configuration. Steroids with 5 beta reduction, i.e. 5 beta-dihydrotestosterone, etiocholanolone and epi-etiocholanolone, at high doses produced the inhibitory effect. Testosterone and its closer 5 alpha metabolites (5 alpha-dihydrotestosterone and 5 alpha-androstanedione) were ineffective. The depressive effect of androsterone on neurones was antagonized by the intraventricular injection of ruthenium red. On the other hand, the convulsant effect of ruthenium red was prevented or diminished by the action of androsterone. These findings support the hypothesis that testosterone metabolites reduced either at 5 alpha or 5 beta position can act in the brain at a membrane level and raise the possibility that testosterone may be a prehormone in the regulation of excitability in some brain functions.

(3-H)-dihydrotestosterone in catecholamine neurons of rat brain stem: combined localization by autoradiography and formaldehyde-induced fluorescence

A combined formaldehyde-induced fluorescence (FIF)-autoradiography procedure was used to determine how and where the androgen, dihydrotestosterone (DHT), is associated with catecholamine systems in the rat brain. With this dual localization method, (3H)-DHT target sites can be visualized in relation to catecholamine perikarya and terminals. In the hindbrain, catecholamine neurons adjacent to the fourth ventricle (group A4), the nucleus (n.) olivaris superior (group A5), the n. parabranchialis medialis (group A7), and in the locus coeruleus (group A6) and subcoeruleal regions, as well as in the substantia grisea centralis, concentrate (3H)-DHT in their nuclei. (3H)-DHT target neurons appear to be innervated by numerous catecholamine terminals in the following hindbrain regions: n. motorius dorsalis nervi vagi, n. tractus solitarii, n. commissuralis, n. raphe pallidus, n. olivaris inferior, the ventrolateral portion of the substantia grisea centralis, n. cuneiformis, and the ventrolateral reticular formation in the caudal mesencephalon. In the forebrain, (3H)-DHT concentrates in nuclei of catecholamine neurons located in the n. arcuatus and n. periventricularis (group A12). In addition, (3H)-DHT target neurons appear to be innervated by numerous catecholamine terminals in the following forebrain regions: n. periventricularis rotundocellularis, n. paraventricularis, n. dorsomedialis, n. periventricularis, area retrochiasmatica, n. interstititalis striae terminalis (ventral portion), and n. amygdaloideus centralis. The disclosure of a morphologic association between (3H)-DHT target sites and certain brain catecholamine systems suggests a close functional interdependence between androgens and catecholamines.