Impact of very old age on hypothalamic dopaminergic neurons in the female rat:: A morphometric study
Impact of very old age on hypothalamic dopaminergic neurons in the female rat:: A morphometric study
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DOI：
10.1002/cne.10564
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发表时间：
2003-04-14
影响因子：
2.5
通讯作者：
Zuccolilli, GO
中科院分区：
文献类型：
--
作者：
Sánchez, HL;Silva, LB;Zuccolilli, GO
下丘脑A（12）（结节漏斗多巴胺能系统）和A（11）（室周多巴胺能系统）区的多巴胺能神经元对催乳素分泌进行紧张性抑制控制。已知大鼠大脑漏斗部多巴胺能系统神经元功能在衰老过程中下降，但关于极端年龄对这两个系统中神经元数量和形态的影响知之甚少。我们形态计量学评估的神经元结节漏斗多巴胺能系统和脑室周围多巴胺能系统的雌性大鼠6（年轻，Y），24（老年，0），和30-32（衰老，S）月龄。固定的下丘脑连续冠状切片进行酪氨酸羟化酶的化学标记，并对A（12）和A（14）区的免疫反应性胞体进行定量表征，并在三个年龄组之间进行比较。采用放射免疫法测定血清催乳素。A（12）酪氨酸羟化酶免疫反应性胞体的数量随年龄增长而逐渐减少，而A（14）酪氨酸羟化酶免疫反应性胞体的数量从青年到老年保持稳定，但在衰老大鼠中急剧下降。在老年大鼠中，酪氨酸羟化酶免疫反应神经元面积（A（12）= 135.37和A（14）= 158.79 mum（2））显著高于年轻（A（12）= 72.56和A（14）= 99.7 mum（2））和衰老动物（A（12）= 95.5和A（14）= 106.5 mum（2））。正中隆起酪氨酸羟化酶免疫反应性的光密度评估显示，正中隆起中的酪氨酸羟化酶含量与年龄相关地稳定减少。血清催乳素水平随着年龄的增长而稳步上升。我们的结论是，在雌性大鼠中，老化带来了结节漏斗多巴胺能系统和脑室周围多巴胺能系统神经元的进行性损失，这在极端年龄变得更加明显。(C)2003 Wiley-Liss，Inc.
Dopaminergic neurons of the A(12) (tuberoinfundibular dopaminergic system) and A,, (periventricular dopaminergic system) hypothalamic areas exert a tonic inhibitory control of prolactin secretion. Tuberoinfundibular dopaminergic system neuron function is known to decline during aging in rats, but little is known about the impact of extreme age on neuron number and morphology in the two systems. We morphometrically assessed the neurons of the tuberoinfundibular dopaminergic system and the periventricular dopaminergic system in female rats 6 (young, Y), 24 (old, 0), and 30-32 (senescent, S) months old. Serial coronal sections of fixed hypothalami were immunohistochemically labeled for tyrosine hydroxylase, and immunoreactive perikarya from the A(12) and A(14) areas were quantitatively characterized and compared among the three age groups. Radioimmunoassay was used to measure serum prolactin. The number of A(12) tyrosine hydroxylase-immunoreactive perikarya showed a steady decline with age, whereas the number of A(14) tyrosine hydroxylase-immunoreactive perikarya remained stable from young to old age but showed a sharp drop in the senescent rats. In the old rats, tyrosine hydroxylase-immunoreactive neuronal area (A(12) = 135.37 and A(14) = 158.79 mum(2)) was significantly higher than that of young (A(12) = 72.56 and A(14) = 99.7 mum(2)) and senescent animals (A(12) = 95.5 and A(14) = 106.5 mum(2)). Densitometric assessment of median eminence tyrosine hydroxylase immunoreactivity revealed a steady age-related reduction of tyrosine hydroxylase content in the median eminence. Serum prolactin levels increased steadily with age. We conclude that, in the female rat, aging brings about a progressive loss of both tuberoinfundibular dopaminergic system and periventricular dopaminergic system neurons, which becomes more conspicuous at extreme ages. (C) 2003 Wiley-Liss, Inc.