H.A. Oelschläger1 and H. Jastrow2
1) Department of Anatomy, Johann Wolfgang Goethe-University,
Theodor Stern-Kai 7, D-60590 Frankfurt a.M.;
2) Department of Anatomy, J. Gutenberg-University, Becherweg 13, D-55128 Mainz.
Five big brown bats (3m, 2f) ranging from juvenile to adult animals
(cryotome and cryostat sections) were investigated with the methods of
immunocytochemistry (Sternberger 1974).
Within the Nervus terminalis (N.t.), variation of LHRH cell number was moderate (range 5-129; average: 68); there were almost twice as many spindle-shaped cells as irregular cells. In the brain, the degree of variation was about the same as in the N.t. (range: 528-1.047; average: 713); however, the spindle-shaped cells were 3.5 times as numerous as the irregular cells.
In the nervous system as a whole, there were only minor differences between left and right (averages: 350 [left] and 332 [right]). There was so significant difference between both sexes and no obvious numerical trend during postnatal ontogenesis. On an average, the postnatal big brows bat exhibits 780 LHRH-ir cells within the N.t. and forebrain, which is distinctly more than in the mole rat (Jastrow et al., this volume) and much more than in the mouse (Schwanzel-Fukuda et al. 1987) and the musk shrew (Dellovade and Rissman 1994). It should be noted that, within the Nervus terminalis of mammals, the LHRH-ir cells represent only one neuron population, which shows marked regression in parallel to the establishment of the brain-pituitary-gonadal axis during the late fetal period.
* supported by Deutsche Forschungsgemeinschaft (DFG) Oel-103/2-1
Dr. Senckenbergische Stiftung, Frankfurt am Main, FRG