RELEASE OF PEPTIDE COTRANSMITTERS FROM A CHOLINERGIC MOTOR NEURON UNDER PHYSIOLOGICAL CONDITIONS
RELEASE OF PEPTIDE COTRANSMITTERS FROM A CHOLINERGIC MOTOR NEURON UNDER PHYSIOLOGICAL CONDITIONS
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DOI：
10.1073/pnas.87.3.933
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发表时间：
1990-02-01
影响因子：
11.1
通讯作者：
WEISS, KR
中科院分区：
文献类型：
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作者：
CROPPER, EC;PRICE, D;WEISS, KR
在以前的研究中，我们证明，B15，两个胆碱能运动神经元的副齿舌更近的肌肉，合成两种肽，小心脏活性肽A和B（SCPA和SCPB），当外源性应用，增加肌肉收缩的大小和松弛率引起的运动神经元刺激。在本实验中，我们获得了SCP在生理条件下释放的证据。具体而言，我们的特点是在正常行为的运动神经元B15的放电模式，模拟他们在体外，并证明了这种类型的神经元活动产生的SCP水平在神经元的过程和终端的下降。我们还获得的证据表明，足够的SCP在生理条件下释放，以调节神经肌肉活动的副齿舌更接近。我们证明，神经元B15的生理活动产生肌肉cAMP水平显着增加。此外，肌肉收缩的大小和松弛速率的增加可以通过改变刺激参数来产生，这也可能使释放的内源性SCPA和SCPB的效果最大化。
In previous studies, we demonstrated that B15, one of the two cholinergic motor neurons of the accessory radula closer muscle of Aplysia, synthesizes two peptides, small cardioactive peptides A and B (SCPA and SCPB), that, when exogenously applied, increase the size and relaxation rate of muscle contractions elicited by motor neuron stimulation. In the present experiments, we obtained evidence that the SCPs are released under physiological conditions. Specifically, we characterized firing patterns of motor neuron B15 during normal behavior, simulated them in vitro, and demonstrated that this type of neuronal activity produces decreases in SCP levels in neuronal processes and terminals. We also obtained evidence that suggests that enough SCP is released under physiological conditions to modulate neuromuscular activity in the accessory radula closer. We demonstrated that physiological activity of neuron B15 produces significant increases in muscle cAMP levels. Furthermore, increases in the size and relaxation rate of muscle contractions can be produced by changes in stimulation parameters that are also likely to maximize effects of released endogenous SCPA and SCPB.