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.