Elham Hakimizadeh - Physiology-Pharmacology Research Centre, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
Shahrbanoo Oryan - Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
Akbar Hajizadeh moghaddam - Department of Biology, Faculty of Basic Sciences, University of Mazandaran, Babolsar, Iran
Ali Shamsizadeh - Physiology-Pharmacology Research Centre, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
Ali Roohbakhsh - Physiology-Pharmacology Research Centre, Rafsanjan University of Medical Sciences, Rafsanjan, Iran

Objective(s) Fatty acid is amide hydrolase which reduce endogenous anandamide. Transient receptor potential vanilloid-۱ (TRPV۱) channels have been reported to have a role in the modulation of anxiety-like behaviors in rodents. In the present study, the effects of either endocannabinoid system or TRPV۱ channels and their possible interaction on anxiety-like behaviors of the rats were explored. Materials and Methods Elevated plus-maze test of anxiety was used to induce anxiety. Capsaicin and AMG ۹۸۱۰ as TRPV۱ agonist and antagonist respectively were injected into the dorsal hippocampus. URB ۵۹۷ as selective FAAH inhibitor and AM ۲۵۱ as CB۱ receptor selective antagonist were also injected into the dorsal hippocampus. The effect of AMG ۹۸۱۰ on the response of URB ۵۹۷ was also examined. Results Intra-CA۱ injection of URB ۵۹۷ (۰.۰۰۱, ۰.۰۱ and ۰.۱ µg/rat) and AMG ۹۸۱۰ (۰.۰۰۳, ۰.۰۳ and ۰.۳ µg/rat) produced anxiolytic-like effects. Intra-CA۱ infusion of capsaicin (۰.۰۰۳, ۰.۰۳ and ۰.۳ µg/rat) increased the anxiety-related behaviors and AM ۲۵۱ (۰.۰۰۱, ۰.۰۱ and ۰.۱ µg/rat) did not significantly change the animals behavior. AMG ۹۸۱۰ at the dose of ۰.۰۰۳ µg/rat did not change the anxiolytic-like effect of URB ۵۹۷. Conclusion The results of the present study demonstrated that both endocannabinoid system and TRPV۱ receptors may affect anxiety-like behaviors. In addition, it seems that TRPV۱ receptors are not involved in the effects of anandamide on anxiety-related behaviors in the CA۱ region.

Anandamide, Anxiety, CA۱ region, Fatty-acid amide hydrolase, Rats, TRPV Cation Channels