Division of Urology, Department of Surgery, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
J Sex Med. 2014 Mar;11(3):664-77. doi: 10.1111/jsm.12418. Epub 2013 Dec 20.
The pelvic striated muscles play an important role in mediating erections and ejaculation, and together these muscles compose a tightly coordinated neuromuscular system that is androgen sensitive and sexually dimorphic.
To identify spinal and brains neurons involved in the control of the levator ani (LA) and bulbospongiosus (BS) in the male adult and preadolescent rat.
Rats were anesthetized, and the transsynaptic retrograde tracer pseudorabies virus (PRV) was injected into the LA muscle of adults or the ventral BS muscle in 30-day-old rats. After 3-5 days rats were sacrificed, and PRV-labeled neurons in the spinal cords and brains were identified using immunohistochemistry. The presence of gastrin-releasing peptide (GRP) in the lumbar spinal neurons was examined.
The location and number of PRV-labeled neurons in the spinal cord and brain and GRP colocalization in the lumbar spinal cord.
PRV-labeled spinal interneurons were found distributed throughout T11-S1 of the spinal cord, subsequent to dorsal medial motoneuron infection. The majority of spinal interneurons were found in the lumbosacral spinal cord in the region of the dorsal gray commissure and parasympathetic preganglionic neurons. Preadolescent rats had more PRV-labeled spinal interneurons at L5-S1 where the motoneurons were located but relatively less spread rostrally in the spinal cord compared with adults. Lumbar spinothalmic neurons in medial gray of L3-L4 co-localized PRV and GRP. In the brain consistent labeling was seen in areas known to be involved in male sexual behavior including the ventrolateral medulla, hypothalamic paraventricular nucleus, and medial preoptic area.
Common spinal and brain pathways project to the LA and BS muscles in the rat suggesting that these muscles act together to coordinate male sexual reflexes. Differences may exist in the amount of synaptic connections/neuronal pathways in adolescents compared with adults.
骨盆横纹肌在介导勃起和射精中起着重要作用，这些肌肉共同构成了一个紧密协调的神经肌肉系统，对雄激素敏感且具有性别二态性。
鉴定成年和青春期前大鼠阴部内肌（LA）和球海绵体肌（BS）控制中涉及的脊髓和脑神经元。
大鼠麻醉后，将跨突触逆行示踪剂伪狂犬病毒（PRV）注入成年大鼠的 LA 肌肉或 30 日龄大鼠的 BS 肌肉。3-5 天后，大鼠被处死，使用免疫组织化学鉴定脊髓和脑中的 PRV 标记神经元。检查腰椎神经元中胃泌素释放肽（GRP）的存在。
脊髓和脑内 PRV 标记神经元的位置和数量以及腰椎脊髓中 GRP 的共定位。
PRV 标记的脊髓中间神经元分布在 T11-S1 的脊髓中，随后感染背内侧运动神经元。大多数脊髓中间神经元位于腰骶脊髓的背侧灰质连合和副交感节前神经元区域。青春期前大鼠在 L5-S1 处有更多的 PRV 标记的脊髓中间神经元，而在 L5-S1 处的运动神经元位于 L5-S1 处，而在脊髓中向头侧的扩散相对较少。L3-L4 中内侧灰质的腰骶脊髓丘脑神经元与 PRV 和 GRP 共定位。在大脑中，在已知参与雄性性行为的区域中观察到一致的标记，包括腹外侧延髓、下丘脑室旁核和内侧视前区。
大鼠的 LA 和 BS 肌肉有共同的脊髓和脑通路投射，这表明这些肌肉共同作用以协调男性的性反射。在青少年和成年人之间，突触连接/神经元通路的数量可能存在差异。
