Searchable, peer-reviewed, open-access proceedings from bioscience and biomedical conferences

bp0005rdr23 | Neuroendocrine Interactions | REDR2002

Origin of cerebrospinal fluid melatonin and possible function in the integration of photoperiod

Tricoire H , Møller M , Chemineau P , Malpaux B

Melatonin, which is synthesized at night by the pineal gland, is present in the cerebrospinal fluid (CSF), but its entry site and its role in this compartment are not known. Using several approaches, we tested the hypothesis that melatonin enters the CSF through the pineal recess, an evagination of the third ventricle. CSF melatonin concentrations are higher near the pineal gland than in the anterior part of the third ventricle, and decrease markedly (80%) after sealing of...

bp0003rdr22 | Regulation of Gonadotrophin Secretion | REDR1994

Dopaminergic control of LH secretion by the Al5 nucleus in anoestrous ewes

Thiery JC , Gayrard V , Le Corre S , Viguié C , Martin GB , Chemineau P , Malpaux B

Annual variations in the secretion of LH are responsible for seasonal changes in ovulatory activity in ewes. This hormonal pattern reflects an increase in the intensity of the negative feedback exerted by oestradiol under long days. Neuro-pharmacological studies have shown that this inhibition of LH secretion involves activation of catecholaminergic systems from preoptic and mediobasal hypothalamus (MBH) by oestradiol during anoestrus, and that 5-hydroxytryptamine inputs may a...

bp0004rdr10 | Comparative Reproductive Function: Implications for Management | REDR1998

Implications of recent advances in reproductive physiology for reproductive management of goats

Chemineau P , Baril G , Leboeuf B , Maurel MC , Roy F , Pellicer-Rubio M , Malpaux B , Cognie Y

The control of reproduction in goats is interesting for technical reasons (synchronization of kiddings, adjustment to forage availability or to economy), and for genetic reasons (identification and dissemination of improved genotypes). The use of short-light rhythms leads to markedly increased production of semen per buck and prevents occurrence of a ‘resting’ season. Recent identification of a bulbourethral lipase in goat spermatozoa opens new perspectives in sperm ...