Research Institute for Electronic Science, Hokkaido University, Sapporo, Hokkaido 060-0812, Japan.
J Exp Biol. 2011 May 15;214(Pt 10):1707-13. doi: 10.1242/jeb.051565.
In ants, including Formica japonica, trophallaxis and grooming are typical social behaviors shared among nestmates. After depriving ants of either food or nestmates and then providing them with either food or nestmates, a behavioral change in type and frequency of social interactions was observed. We hypothesized that starvation and isolation affected levels of brain biogenic amines including dopamine (DA) and octopamine (OA) - neuromediators modifying various insect behaviors - and tested the relationship between brain biogenic amines and social behaviors of stressed ants. Ants starved for 7 days contained lower brain DA levels and they did not perform trophallaxis toward nestmates. Feeding starved ants sucrose solution re-established trophallaxis but not brain DA levels. The performance of trophallaxis induced recovery of brain DA content to the level of untreated ants. Ants that were isolated for 2 days displayed markedly increased OA levels, which following nestmate interactions, returned to levels similar to those of control (non-isolated) ants and ants isolated for 1 h. We conclude that: (1) starvation reduced brain DA level but had no significant effect on brain OA (trophallaxis recovered the brain DA levels), and (2) isolation increased brain OA level but had no effect on brain DA (trophallaxis and grooming events recovered the brain OA levels). We suggest that social interactions with nestmates influenced brain biogenic amine homeostasis in stressed F. japonica.
在蚂蚁中，包括日本弓背蚁，营养交换和梳理是巢内同伴之间典型的社交行为。剥夺蚂蚁食物或同伴后，再给它们提供食物或同伴，观察到社交行为的类型和频率发生了变化。我们假设饥饿和隔离会影响包括多巴胺（DA）和章鱼胺（OA）在内的脑生物胺水平，这些神经递质会调节各种昆虫行为，并测试应激蚂蚁的脑生物胺与社交行为之间的关系。饥饿 7 天的蚂蚁大脑中的 DA 水平较低，它们不会向同伴进行营养交换。给饥饿的蚂蚁喂食蔗糖溶液可以重新建立营养交换，但不能恢复大脑 DA 水平。进行营养交换可以诱导大脑 DA 含量恢复到未处理蚂蚁的水平。隔离 2 天的蚂蚁表现出明显增加的 OA 水平，在与同伴互动后，OA 水平恢复到与对照（非隔离）蚂蚁和隔离 1 小时的蚂蚁相似的水平。我们得出结论：（1）饥饿降低了大脑 DA 水平，但对大脑 OA 没有显著影响（营养交换恢复了大脑 DA 水平）；（2）隔离增加了大脑 OA 水平，但对大脑 DA 没有影响（营养交换和梳理行为恢复了大脑 OA 水平）。我们认为，与同伴的社交互动影响了应激状态下日本弓背蚁的脑生物胺动态平衡。
