title: Effects of neonatal treatment with the TRPV1 agonist, capsaicin, on adult rat brain and behaviour.
abstract: Treatment of neonatal rats with the transient receptor potential vanilloid 1 (TRPV1) channel agonist, capsaicin, produces life-long loss of sensory neurons expressing TRPV1 channels. Previously it was shown that rats treated on day 2 of life with capsaicin had behavioural hyperactivity in a novel environment at 5-7 weeks of age and brain changes reminiscent of those found in subjects with schizophrenia. The objective of the present study was to investigate brain and behavioural responses of adult rats treated as neonates with capsaicin. It was found that the brain changes found at 5-7 weeks in rats treated as neonates with capsaicin persisted into adulthood (12 weeks) but were less in older rats (16-18 weeks). Increased prepulse inhibition (PPI) of acoustic startle was found in these rats at 8 and 12 weeks of age rather than the deficit commonly found in animal models of schizophrenia. Subjects with schizophrenia also have reduced flare responses to niacin and methylnicotinate proposed to be mediated by prostaglandin D2 (PGD2). Flare responses are accompanied by cutaneous plasma extravasation. It was found that the cutaneous plasma extravasation responses to methylnicotinate and PGD2 were reduced in capsaicin-treated rats. In conclusion, several neuroanatomical changes observed in capsaicin-treated rats, as well as the reduced cutaneous plasma extravasation responses, indicate that the role of TRPV1 channels in schizophrenia is worthy of investigation.
authors: School of Biomedical Sciences and Pharmacy, University of Newcastle, NSW 2308, Australia; Schizophrenia Research Institute, 405 Liverpool St, Darlinghurst, NSW 2010, Australia.
authors: Penny N
authors: PN
authors: Newson
authors: Mental Health Research Institute, Parkville, Victoria 3052, Australia; School of Psychological Science, La Trobe University, Melbourne, Australia.
authors: Maarten
authors: M
authors: van den Buuse
authors: Mental Health Research Institute, Parkville, Victoria 3052, Australia.
authors: Sally
authors: S
authors: Martin
authors: School of Biomedical Sciences and Pharmacy, University of Newcastle, NSW 2308, Australia; Schizophrenia Research Institute, 405 Liverpool St, Darlinghurst, NSW 2010, Australia.
authors: Ann
authors: A
authors: Lynch-Frame
authors: School of Biomedical Sciences and Pharmacy, University of Newcastle, NSW 2308, Australia; Schizophrenia Research Institute, 405 Liverpool St, Darlinghurst, NSW 2010, Australia. Electronic address: loris.chahl@newcastle.edu.au.
authors: Loris A
authors: LA
authors: Chahl
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D000831:Animals, Newborn; D001307:Auditory Perception / Q000187:drug effects / Q000502:physiology; D001921:Brain / Q000187:drug effects* / Q000254:growth & development* / Q000473:pathology / Q000503:physiopathology; D002211:Capsaicin / Q000633:toxicity*; D005260:Female; D008297:Male; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D018377:Neurotransmitter Agents / Q000633:toxicity*; D009525:Niacin; D009539:Nicotinic Acids; D009929:Organ Size; D065808:Prepulse Inhibition / Q000187:drug effects / Q000502:physiology; D015230:Prostaglandin D2 / Q000008:administration & dosage; D017208:Rats, Wistar; D013216:Reflex, Startle / Q000187:drug effects / Q000502:physiology; D012879:Skin Physiological Phenomena / Q000187:drug effects; D050916:TRPV Cation Channels / Q000819:agonists* / Q000378:metabolism
chemical_list: D018377:Neurotransmitter Agents; D009539:Nicotinic Acids; D050916:TRPV Cation Channels; C493922:Trpv1 protein, rat; D009525:Niacin; C008473:methyl nicotinate; D015230:Prostaglandin D2; D002211:Capsaicin
keywords: Capsaicin; Methylnicotinate; Neonatal rat; Prepulse inhibition; Schizophrenia; TRPV1