Hurwitz I, Perrins R, Xin Y, Weiss K R, Kupfermann I
Department of Physiology and Biophysics, Mount Sinai School of Medicine, New York 10029, USA.
J Neurophysiol. 1999 Feb;81(2):521-34. doi: 10.1152/jn.1999.81.2.521.
Head lifting and other aspects of the appetitive central motive state that precedes consummatory feeding movements in Aplysia is promoted by excitation of the C-PR neuron. Food stimuli activate C-PR as well as a small population of cerebral-buccal interneurons (CBIs). We wished to determine if firing of C-PR produced differential effects on the various CBIs or perhaps affected all the CBIs uniformly as might be expected for a neuron involved in producing a broad undifferentiated arousal state. We found that when C-PR was fired, it produced a wide variety of effects on various CBIs. Firing of C-PR evoked excitatory input to a newly identified CBI (CBI-12) the soma of which is located in the M cluster near the previously identified CBI-2. CBI-12 shares certain properties with CBI-2, including a similar morphology and a capacity to drive rhythmic activity of the buccal-ganglion. Unlike CBI-2, CBI-12 exhibits myomodulin immunoreactivity. Furthermore when C-PR is fired, CBI-12 receives a polysynaptic voltage-dependent slow excitation, whereas, CBI-2 receives relatively little input. C-PR also polysynaptically excites other CBIs including CBI-1 and CBI-8/9 but produces inhibition in CBI-3. In addition, firing of C-PR inhibits plateau potentials in CBI-5/6. The data suggest that activity of C-PR may promote the activity of one subset of cerebral-buccal interneurons, perhaps those involved in ingestive behaviors that occur during the head-up posture. C-PR also inhibits some cerebral-buccal interneurons that may be involved in behaviors in which C-PR activity is not required or may even interfere with other feeding behaviors such as rejection or grazing, that occur with the head down.
在海兔中，摄食性中枢动机状态的抬头及其他方面先于 consummatory 摄食运动，这是由 C-PR 神经元的兴奋所促进的。食物刺激会激活 C-PR 以及一小部分脑-口中间神经元（CBIs）。我们希望确定 C-PR 的放电是否会对各种 CBIs 产生不同的影响，或者是否会像参与产生广泛无差别唤醒状态的神经元所预期的那样，对所有 CBIs 产生均匀的影响。我们发现，当 C-PR 放电时，它会对各种 CBIs 产生多种影响。C-PR 的放电会引发对一个新鉴定的 CBI（CBI-12）的兴奋性输入，其胞体位于先前鉴定的 CBI-2 附近的 M 簇中。CBI-12 与 CBI-2 具有某些共同特性，包括相似的形态和驱动口神经节节律性活动的能力。与 CBI-2 不同，CBI-12 表现出肌调蛋白免疫反应性。此外，当 C-PR 放电时，CBI-12 会接受多突触电压依赖性慢兴奋，而 CBI-2 接受的输入相对较少。C-PR 还通过多突触兴奋其他 CBIs，包括 CBI-1 和 CBI-8/9，但对 CBI-3 产生抑制作用。此外，C-PR 的放电会抑制 CBI-5/6 中的平台电位。数据表明，C-PR 的活动可能会促进脑-口中间神经元的一个子集的活动，也许是那些参与抬头姿势期间摄食行为的神经元。C-PR 还会抑制一些可能参与不需要 C-PR 活动的行为的脑-口中间神经元，或者甚至可能干扰其他摄食行为，如下头时发生的拒绝或啃食行为。
