title: Anxiolytic efficacy of repeated oral capsaicin in rats with partial aberration of oral sensory relay to brain.
abstract: OBJECTIVE
  This study was conducted to examine if taste over load with oral capsaicin improves the adverse behavioural effects induced by partial aberration of oral sensory relays to brain with bilateral transections of the lingual and chorda tympani nerves.
  
  
  METHODS
  Male Sprague-Dawley rats received daily 1 ml of 0.02% capsaicin or water drop by drop into the oral cavity following the bilateral transections of the lingual and chorda tympani nerves. Rats were subjected to ambulatory activity, elevated plus maze and forced swim tests after 11th, 14th and 17th daily administration of capsaicin or water, respectively. The basal and stress-induced plasma corticosterone levels were examined after the end of behavioural tests.
  
  
  RESULTS
  Ambulatory counts, distance travelled, centre zone activities and rearing were increased, and rostral grooming decreased, during the activity test in capsaicin treated rats. Behavioural scores of capsaicin rats during elevated plus maze test did not differ from control rats. Immobility during the swim test was decreased in capsaicin rats with near significance (P = 0.0547). Repeated oral capsaicin increased both the basal level and stress-induced elevation of plasma corticosterone in rats with bilateral transections of the lingual and chorda tympani nerves.
  
  
  CONCLUSIONS
  It is concluded that repeated oral administration of capsaicin reduces anxiety-like behaviours in rats that received bilateral transections of the lingual and chorda tympani nerves, and that the increased corticosterone response, possibly modulating the hippocampal neural plasticity, may be implicated in the anxiolytic efficacy of oral capsaicin.
authors: Program in Craniofacial Structure and Functional Biology, Department of Dental Science, Graduate School, Seoul National University, Republic of Korea; Department of Oral and Maxillofacial Surgery, Dental Center, Chung-Ang University School of Medicine, Seoul, Republic of Korea.
authors: Young-Jun
authors: YJ
authors: Choi
authors: Program in Craniofacial Structure and Functional Biology, Department of Dental Science, Graduate School, Seoul National University, Republic of Korea; Department of Oral and Maxillofacial Surgery, Dental Research Institute, Seoul National University School of Dentistry, Seoul, Republic of Korea.
authors: Jin Young
authors: JY
authors: Kim
authors: Program in Craniofacial Structure and Functional Biology, Department of Dental Science, Graduate School, Seoul National University, Republic of Korea; Department of Oral and Maxillofacial Surgery, Dental Research Institute, Seoul National University School of Dentistry, Seoul, Republic of Korea.
authors: Wei-Peng
authors: WP
authors: Jin
authors: Program in Craniofacial Structure and Functional Biology, Department of Dental Science, Graduate School, Seoul National University, Republic of Korea.
authors: Yoon-Tae
authors: YT
authors: Kim
authors: Program in Craniofacial Structure and Functional Biology, Department of Dental Science, Graduate School, Seoul National University, Republic of Korea; Department of Oral and Maxillofacial Surgery, Dental Research Institute, Seoul National University School of Dentistry, Seoul, Republic of Korea. Electronic address: leejongh@snu.ac.kr.
authors: Jong-Ho
authors: JH
authors: Lee
authors: Department of Oral and Maxillofacial Surgery, Dental Research Institute, Seoul National University School of Dentistry, Seoul, Republic of Korea. Electronic address: jwjahng@snu.ac.kr.
authors: Jeong Won
authors: JW
authors: Jahng
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001007:Anxiety / Q000188:drug therapy*; D015415:Biomarkers / Q000097:blood; D002211:Capsaicin / Q000008:administration & dosage / Q000494:pharmacology*; D002814:Chorda Tympani Nerve / Q000601:surgery*; D003345:Corticosterone / Q000097:blood; D008036:Lingual Nerve / Q000601:surgery*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013312:Stress, Physiological
chemical_list: D015415:Biomarkers; D002211:Capsaicin; D003345:Corticosterone
keywords: Anxiety; Corticosterone; Lingual nerve; Oral sensory