From hunger to satiety:: Reconfiguration of a feeding network by Aplysia neuropeptide Y
From hunger to satiety:: Reconfiguration of a feeding network by Aplysia neuropeptide Y
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DOI：
10.1523/jneurosci.0334-07.2007
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发表时间：
2007-03-28
影响因子：
5.3
通讯作者：
Weiss, Klaudiusz R.
中科院分区：
文献类型：
--
作者：
Jing, Jian;Vilim, Ferdinand S.;Weiss, Klaudiusz R.
动机状态的转变通常会产生行为改变，但其潜在机制却知之甚少。在海洋软体动物加利福尼亚海陆中，由进食引起的从饥饿到饱足状态的转变会导致进食速度减慢并最终终止。由于多功能摄食网络既产生摄食反应，也产生摄食反应，因此从饥饿到饱腹状态的转变可能与网络重构有关，从而导致摄食反应减少，摄食反应增加。自由饲养的海鲢的慢性电生理记录显示，随着进食的进行，食物引起的摄食反应减少，同时增加了摄食反应的次数。注射海芋神经肽Y （apNPY）可减少摄食，减慢摄食速度。apNPY局限于起源于肠支配食道神经（EN）的颊神经节传入神经，这条神经参与饱足和产生消化程序。在EN刺激时，apNPY在进食回路中被释放。重要的是，在apNPY存在的情况下，刺激脑-颊间神经元-2（一种被食物激活并通常引起摄取反应的命令样中间神经元）会引起摄取反应。这伴随着促排卵中间神经元B20活性的增加和促摄入中间神经元B40活性的降低。因此，进食中枢模式发生器的apNPYergic重构在从饥饿到饱腹状态的逐渐过渡中发挥了作用。更一般地说，动机状态的变化可能不仅涉及简单的网络抑制，还可能需要网络重构。
A shift in motivational state often produces behavioral change, but the underlying mechanisms are poorly understood. In the marine mollusc, Aplysia californica, feeding-induced transition from a hunger to satiation state leads to a slowdown and an eventual termination of feeding. Because the multifunctional feeding network generates both ingestion and the competing response, egestion, it is possible that the transition from a hunger to a satiety state is associated with network reconfiguration that results in production of fewer ingestive and more egestive responses. Chronic electrophysiological recordings in free-feeding Aplysia showed that as the meal progressed, food elicited fewer ingestive responses and simultaneously increased the number of egestive responses. Injections of Aplysia neuropeptide Y (apNPY) reduced food intake and slowed down the rate of ingestion. apNPY was localized to buccal-ganglion afferents originating in the gut-innervating esophageal nerve (EN), a nerve involved both in satiation and in the generation of egestive programs. During EN stimulation, apNPY was released in the feeding circuit. Importantly, stimulation of the cerebral-buccal interneuron-2, a command-like interneuron that is activated by food and normally elicits ingestive responses, elicited egestive responses in the presence of apNPY. This was accompanied by increased activity of the egestion-promoting interneuron B20 and decreased activity in the ingestion-promoting interneuron B40. Thus, apNPYergic reconfiguration of the feeding central pattern generator plays a role in the gradual transition from hunger to satiety states. More generally, changes in the motivational states may involve not only simple network inhibition but may also require network reconfiguration.