Battisti W P, Levin B E, Murray M
Department of Anatomy, Medical College of Pennsylvania/EPPI, Philadelphia 19129.
Brain Res. 1987 Aug 25;418(2):287-300. doi: 10.1016/0006-8993(87)90096-5.
We used correlative biochemical and histochemical methods to examine (1) the norepinephrine (NE) projection from the paired locus coeruleus (LC) to the midline interpeduncular nucleus (IPN) of the adult rat and (2) the ability of the LC to respond to denervation of their target following removal of noradrenergic afferents (6-hydroxydopamine lesions of the LC) or non-noradrenergic afferents (lesion of the paired fasciculi retroflexi(FR]. Histofluorescence revealed that the NE innervation from the two LC to the IPN is symmetric and overlapping. This projection is confined to rostral, central, and intermediate subnuclei and is absent from lateral and dorsal subnuclei. We found no evidence for homotypic collateral sprouting of undamaged LC neurons into the IPN following unilateral LC lesion. Bilateral LC lesions also did not induce sprouting by NE-containing neurons from other systems (e.g. the superior cervical ganglion or the lateral tegmental group) or from those LC neurons that survived the 6-hydroxydopamine lesion. Histofluorescence following bilateral FR lesions confirmed an earlier observation that apparent hyperinnervation of the IPN by LC afferents is elicited following removal of non-noradrenergic afferents. Measurements of the turnover rate of NE in the IPN of control animals and those that received bilateral FR lesions indicate an increased NE content and increased turnover rate of NE in the IPN of lesioned animals. Taken together these results suggest an increased number of NE terminals and an increase in the activity of tyrosine hydroxylase. No change in NE content or turnover rate was seen in the frontal cortex from these same animals. This is consistent with a target-dependent regulation of heterotypic collateral sprouting.
（1）成年大鼠成对蓝斑（LC）到中线脚间核（IPN）的去甲肾上腺素（NE）投射；（2）在去除去甲肾上腺素能传入纤维（LC的6-羟基多巴胺损伤）或非去甲肾上腺素能传入纤维（成对的后屈束（FR）损伤）后，LC对其靶标去神经支配的反应能力。组织荧光显示，从两个LC到IPN的NE神经支配是对称且重叠的。这种投射局限于吻侧、中央和中间亚核，外侧和背侧亚核则没有。我们没有发现单侧LC损伤后未受损的LC神经元向IPN进行同型侧支发芽的确切证据。双侧LC损伤也未诱导来自其他系统（如颈上神经节或外侧被盖组）或在6-羟基多巴胺损伤后存活的LC神经元的含NE神经元发芽。双侧FR损伤后的组织荧光证实了早期的一项观察结果，即去除非去甲肾上腺素能传入纤维后，LC传入纤维对IPN出现明显的超神经支配。对对照动物和接受双侧FR损伤动物的IPN中NE周转率的测量表明，损伤动物的IPN中NE含量增加且NE周转率升高。综合这些结果表明NE终末数量增加以及酪氨酸羟化酶活性增强。这些相同动物的额叶皮质中NE含量或周转率没有变化。这与异型侧支发芽的靶标依赖性调节一致。
