Effect of Tactile Learning on Serum Levels of IL-17 in Male Rats

Interleukin-17 is a pro-inflammatory cytokine secreted by different cells including sensory and motor neurons in the cerebral cortex, hippocampus and spinal cord. As it seems that immune system and cytokines can modulate the brain functions and as IL-17 is expressed by sensory neurons, in this study we investigate the possible role of IL-17 in modulating tactile learning by measuring plasma levels of IL-17 before and after induction of tactile learning.

In this study, 20 male Wistar rats weighing 160-200gr were used. Tactile learning was induced by novel object recognition test (NORT) (based on natural tendency of animal to explore novel objects more than familiar objects). One week before and immediately after the NORT, blood samples were collected to measure the changes in IL-17 concentration before and after learning. Blood was taken from inner canthus of rat's eyes and serum levels of IL-17 were measured using ELISA.

The mean plasma concentrations of IL-17 one week before and immediately after the NORT were 594.4±71.6 and 210±56.5 pg/ml, respectively. The serum level of IL-17 was significantly decreased following induction of tactile learning (p<0.05).

The result of this study showed that, IL-17 may be has a role in modulating higher brain functions such as learning and memory.