A developmental study of the gonadotropin-releasing hormone neuronal system during sexual maturation in the male Djungarian hamster.
A developmental study of the gonadotropin-releasing hormone neuronal system during sexual maturation in the male Djungarian hamster.
复制标题
雄性准加仓鼠性成熟过程中促性腺激素释放激素神经元系统的发育研究。
DOI：
10.1095/biolreprod45.3.440
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发表时间：
1991
影响因子：
3.6
通讯作者：
Newman,SW
中科院分区：
文献类型：
--
作者：
Yellon,SM;Newman,SW
The number, morphology, and distribution of gonadotropin-releasing hormone cell bodies were studied in the brain of the male Djungarian hamster during sexual maturation. Males were reared in long days (16L:8D) and were killed at 15, 25, or 40 days of age, before (n = 5), during (n = 4), or after puberty (n = 4), respectively. Brain sections (60 µm) from the rostral olfactory tubercle to the medial basal hypothalamus were processed for GnRH immunocytochemistry. Unipolar and bipolar neurons were immunolabeled for GnRH; both subtypes had smooth cell contours. Analysis of every section from the olfactory tubercle to the arcuate nucleus indicated that at all ages more than 75% of all GnRH-immunoreactive cell bodies were distributed in the diagonal band of Broca, medial preoptic area, lateral preoptic area, and lateral hypothalamic area. GnRH-positive somata were also found in other brain regions, but in each of these areas they represented less than 6% of the total GnRH neuron number. In peripubertal 25-day-old males, during the rapid phase of testes growth, the number of unipolar, but not bipolar, GnRH-labeled cells nearly doubled in the diagonal band of Broca compared to soma numbers in this location in prepubertal 15-day-old males. The same number of unipolar GnRH-stained somata were found in this region in 40-day-old as in 25-day-old hamsters. In the medial preoptic area, a similar doubling of unipolar neuron numbers was observed at 25 days, but by 40 days the number of unipolar immunostained GnRH cells was secondarily reduced to a level comparable to that at 15 days. Neither the number nor the distribution of bipolar immunoreactive GnRH perikarya changed from 15 to 25 days of age. However, by age 40 days, a significant increase in the bipolar subtype number was evident in the diagonal band of Broca and lateral preoptic area compared to that in 15-day-old males, GnRH neuron numbers and subtype ratios remained unchanged in other brain regions during development. Overall, the findings indicated an increase in the number of unipolar GnRH-stained neurons correlated with the onset of puberty and a later increase in bipolar cells in the postpubertal hamster.
