Insect psychoneuroimmunology: immune response reduces learning in protein starved bumblebees (Bombus terrestris).

It is well established in vertebrates that there are many intricate interactions between the immune system and the nervous system. Here, we present behavioural evidence indicating a link between the immune system and the nervous system in insects. We show that otherwise non-infected bumblebees whose immune systems were challenged by a non-pathogenic immunogenic elicitor (lipopolysaccharide) have reduced abilities to learn or recall a memory in a classical conditioning paradigm. There is evidence that protein is intricately involved as this immune induced reduction in memory only becomes apparent after the bees are deprived of pollen (their only protein sources).