Institute of Neurobiology and Department of Anatomy and Neurobiology, University of Puerto Rico, Medical Sciences Campus, 201 Blvd del Valle, San Juan, 00901, Puerto Rico.
J Exp Biol. 2010 Apr;213(Pt 7):1182-94. doi: 10.1242/jeb.040378.
Octopamine-like immunoreactivity was localized to a limited number (<40) of neurons in the Aplysia central nervous system, including three neurons in the paired buccal ganglia (BG) that control feeding movements. Application of octopamine (OA) to the BG circuit produced concentration-dependent (10(-8)-10(-4) mol l(-1)) modulatory actions on the spontaneous burst activity of the bilaterally paired B67 pharyngeal motor neurons (MNs). OA increased B67's burst duration and the number of impulses per burst. These effects reflected actions of OA on the intrinsic tetrodotoxin-resistant driver potential (DP) that underlies B67 bursting. In addition to its effects on B67's burst parameters, OA also increased the rate and regularity of burst timing. Although the bilaterally paired B67 MNs both exhibited rhythmic bursting in the presence of OA, they did not become synchronized. In this respect, the response to OA differed from that of dopamine, another modulator of the feeding motor network, which produces both rhythmicity and synchrony of bursting in the paired B67 neurons. It is proposed that modulators can regulate burst synchrony of MNs by exerting a dual control over their intrinsic rhythmicity and their reciprocal capacity to generate membrane potential perturbations. In this simple system, dopaminergic and octopaminergic modulation could influence whether pharyngeal contractions occur in a bilaterally synchronous or asynchronous fashion.
章鱼胺样免疫反应定位于有限数量（<40）的阿普利亚中央神经系统神经元，包括控制摄食运动的成对的颊神经节（BG）中的三个神经元。章鱼胺（OA）在 BG 回路中的应用对双侧成对的 B67 咽运动神经元（MN）的自发爆发活动产生浓度依赖性（10（-8）-10（-4）mol l（-1））的调制作用。OA 增加了 B67 的爆发持续时间和爆发中的脉冲数。这些作用反映了 OA 对内在河豚毒素抗性驱动电位（DP）的作用，该电位是 B67 爆发的基础。除了对 B67 的爆发参数的影响外，OA 还增加了爆发定时的速率和规律性。尽管在 OA 存在的情况下，双侧成对的 B67 MN 都表现出有节奏的爆发，但它们并没有同步。在这方面，OA 的反应与另一种摄食运动网络调节剂多巴胺不同，后者在成对的 B67 神经元中产生爆发的节律性和同步性。据推测，调节剂可以通过对其内在节律性和相互产生膜电位扰动的能力进行双重控制来调节 MN 的爆发同步性。在这个简单的系统中，多巴胺能和章鱼胺能的调制可以影响咽收缩是双侧同步还是异步发生。
