Neurosecretory activities in the anterior median eminence in relation to photoperiodic testicular responses in young Japanese quail (Coturnix coturnix japonica).

The neurosecretory system which is considered to have an effect, directly or indirectly, on avian gonadal growth has been extensively investigated in various species (see Ishii and Kobayashi, 1962; Farner et al., 1964). More recently, the neurosecretory materials in the anterior median eminence and in the pars nervosa of the Japanese quail under various photoperiodic conditions have been studied quantitatively by the author (Konishi, 1965). It was concluded that the material appeared to be richer in quails under long daily photoperiods than in those subjected to short days. These results are in agreement with the data in Zonotrichia albicolis (Wolfson and Kobayashi, 1962) and Zosterops pulpebrosa japonica (Hirano et al., 1962; Ishii et al., 1962a; Uemura and Kobayashi, 1963), but are incompatible with the results in Zonotrichia leucophrys gambelii (Oksche et al., 1959) and Arras platyrhncos platyrhyncos (Ishii et al., 1962b). However, various differences in experimental conditions make these comparisons complicated. Whether the Gomori positive neurosecretory materials are identical with the "gonadotropin releasing factors" has not yet been determined. Apart from the investigations of the hypothalamic gonadotropin releasing factors (Guillemin, 1964; Igarashi and McCann, 1964; McCann and Ramirez, 1964), it is first required to establish definite relationships between activity of the neurosecretory system and testicular development. If the neurosecretory material in the anterior median eminence controls the synthesis and/