Central GABAergic neuromodulation of nocifensive behaviours in bumble bees. Pasquini et al.

In mammals, nocifensive behaviours are modulated by neuroactive compounds, indicating a complex pain-processing system that may involve subjective experiences beyond nociception. This study aimed to assess the role of GABA in modulating nocifensive behaviour in the bumble bee Bombus terrestris to better understand how pain-like behaviours are regulated in insects. Results showed that oral administration of Gabapentin (0.24 mg/ml), a GABAergic analgesic acting at the central level, reduced heat sensitivity, making bees more likely to pass through a tunnel heated to 50°C, and supressed their nocifensive behaviour. Gene expression analysis revealed a significant increase in brain expression of GAD1 in response to noxious stimulation. These findings indicate that GABA plays a key role in modulating nocifensive behaviours in insects, similar to its role in mammals, suggesting that insects may possess mechanisms for pain modulation that go beyond simple peripheral responses.

在哺乳动物中，伤害感受行为（nocifensive behaviour）可由神经活性化合物调控，这提示其存在复杂的疼痛处理系统，该系统可能涉及超越伤害感受（nociception）的主观体验。本研究旨在探究γ-氨基丁酸（GABA）在调控大地熊蜂（Bombus terrestris）伤害感受行为中的作用，以更好地理解昆虫类群中类疼痛行为的调控机制。实验结果显示，口服给药浓度为0.24 mg/ml的加巴喷丁（Gabapentin）——一种作用于中枢神经系统的γ-氨基丁酸能镇痛剂——可降低熊蜂的热敏感性，使其更易通过温度达50℃的隧道，并抑制其伤害感受行为。基因表达分析结果显示，在有害刺激下，熊蜂脑部谷氨酸脱羧酶1（GAD1）的表达水平显著上调。上述研究结果表明，γ-氨基丁酸（GABA）在昆虫伤害感受行为的调控中发挥关键作用，这一功能与其在哺乳动物中的作用高度相似，提示昆虫可能拥有超越简单外周反应的疼痛调控机制。