Pribbenow B, Erber J
Institut für Biologie, Technische Universität Berlin, Germany.
Neurobiol Learn Mem. 1996 Sep;66(2):109-20. doi: 10.1006/nlme.1996.0052.
Antennal motor activity of the honeybee was used to test the effects of sucrose stimuli and of serotonin and octopamine microinjections into the brain. The antennal scanning behavior was analyzed in behavioral experiments. Activity of an antennal muscle, the "fast pedicellus flexor muscle" which dominates scanning behavior, was used as a physiological measure of modulatory effects. A single sucrose stimulus applied to both the antenna and the proboscis leads to significant increases of the frequency of antennal scanning compared to those of untreated controls and animals stimulated with water. A single sucrose stimulus applied only to the antenna or the proboscis has no significant behavioral effects. Injection of small volumes (approximately 500 pl) of serotonin (5HT) or octopamine (OA) at concentrations of 10(-5) M into the dorsal lobe, the sensory motor center of the antenna, leads to functionally antagonistic behavioral effects. While 5HT injection significantly reduces the antennal scanning frequency, OA significantly enhances it. The degree of behavioral modulation is significantly correlated with the activity of the animals. In animals which display low scanning activity, OA injection has an enhancing effect, while 5HT has no effect. In contrast, 5HT injection, but not OA injection, produces a behavioral effect in animals with high scanning activity. Behavioral changes and changes of activity of the fast pedicellus flexor muscle are closely correlated. Significant, functionally antagonistic effects of 5HT and OA on muscle activity were found after injections of the compounds into the dorsal lobe. 5HT leads to a reduction of the muscle potential frequency starting immediately after injection and lasting at least 15 min. OA injection results in an increase of frequency, which has its maximum 5 min after injection. The experiments demonstrate that sucrose, the reward stimulus during associative learning in the bee, also modulates motor activity under nonassociative conditions. The similar effects of sucrose stimulation and OA injection are consistent with the hypothesis that OA mediates the effects of sucrose stimuli.
利用蜜蜂的触角运动活性来测试蔗糖刺激以及向脑部微量注射血清素和章鱼胺的效果。在行为实验中分析触角扫描行为。触角肌肉“快速梗节屈肌”的活性主导着扫描行为，被用作调节作用的生理指标。与未处理的对照组以及用水刺激的动物相比，同时向触角和喙施加单一蔗糖刺激会导致触角扫描频率显著增加。仅向触角或喙施加单一蔗糖刺激没有显著的行为影响。以10(-5) M的浓度向触角的感觉运动中心背叶微量注射小体积（约500皮升）的血清素（5HT）或章鱼胺（OA）会产生功能上拮抗的行为效应。注射5HT会显著降低触角扫描频率，而注射OA则会显著提高该频率。行为调节程度与动物的活性显著相关。在扫描活性低的动物中，注射OA有增强作用，而注射5HT则没有效果。相反，在扫描活性高的动物中，注射5HT会产生行为效应，而注射OA则不会。行为变化与快速梗节屈肌的活性变化密切相关。将这些化合物注射到背叶后，发现5HT和OA对肌肉活性有显著的、功能上拮抗的效应。注射5HT后，肌肉电位频率立即降低，并至少持续15分钟。注射OA会导致频率增加，在注射后5分钟达到最大值。这些实验表明，蔗糖作为蜜蜂联想学习过程中的奖励刺激，在非联想条件下也能调节运动活性。蔗糖刺激和注射OA的相似效应与OA介导蔗糖刺激效应的假设一致。
