Rationale: Despite the existing anatomical and physiological evidence pointing to the involvement of orexinergic projections from the lateral hypothalamus (LH) in regulating fear-related responses, little is known regarding the contribution of the orexin system in the prelimbic cortex (PL) on contextual fear.
Objectives: We investigated the role of orexin-A (Orx) and orexin type 1 receptors (OrxR) in the PL during the expression of contextual conditioned fear in mice.
Methods: Neural tract tracing of the LH-PL pathway and OrxR immunoreactivity in the PL of C57BL/6 male mice were performed.