title: Simulated acute central Mycoplasma infections in rats induce fever, anorexia, body mass stunting and lethargy but spare memory.
abstract: Despite the documented post-infectious neurological complications of a central nervous system (CNS) Mycoplasma infection in humans, very few studies have investigated the acute inflammatory responses and sickness behaviours induced by CNS Mycoplasma infections. We therefore determined the effect of acute central administration of fibroblast-stimulating lipopeptide-1 (FSL-1), derived from Mycoplasma salivarium, and FAM-20 from a more pathogenic species, namely Mycoplasma pneumoniae, on behavioural and inflammatory responses in rats. Male Sprague-Dawley rats had radiotransmitters implanted, intra-abdominally, to measure body temperature and cage activity continuously. After recovery from surgery, rats were conditioned in a fear conditioning task and then immediately received an intra-cisterna magna (i.c.m.) injection of either: (1) FSL-1 (10 or 100μg/5μl) or its vehicle (phosphate-buffered saline, 5μl), or (2) FAM-20 (10 or 100μg/5μl) or its vehicle (dimethyl sulfoxide, 5μl). Body mass and food intake were measured daily. Memory was assessed seven days after injection using fear conditioning tests. A single, i.c.m. injection of either FSL-1 or FAM-20 induced profound, dose-dependent fever, anorexia, lethargy and body mass stunting in rats. Moreover, rats that received an i.c.m. injection of 100μg/5μl FAM-20 had a significant increase in the concentration of IL-1β in both the hypothalamus and the hippocampus for ~27h after injection. Seven days after FSL-1 or FAM-20 injection, when body mass of rats still was stunted, they maintained their memory for fear of the context and for fear of the tone, despite the increase in hippocampal IL-1β concentration after FAM-20 administration. Thus, acute simulated CNS Mycoplasma infections caused pronounced sickness responses and brain inflammation in rats, but spared fear memory.
authors.affiliation: Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg 2193, South Africa. Electronic address: Tanya.Swanepoel@wits.ac.za.
authors.forename: Tanya
authors.initials: T
authors.lastname: Swanepoel
authors.affiliation: Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg 2193, South Africa. Electronic address: Mariam.Sabbar@wits.ac.za.
authors.forename: Mariam
authors.initials: M
authors.lastname: Sabbar
authors.affiliation: Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg 2193, South Africa. Electronic address: tlbaartman@gmail.com.
authors.forename: Tamzyn L
authors.initials: TL
authors.lastname: Baartman
authors.affiliation: Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg 2193, South Africa.
authors.forename: Helen P
authors.initials: HP
authors.lastname: Laburn
authors.affiliation: Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg 2193, South Africa. Electronic address: Duncan.Mitchell@wits.ac.za.
authors.forename: Duncan
authors.initials: D
authors.lastname: Mitchell
authors.affiliation: Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg 2193, South Africa. Electronic address: Tanusha.Dukhan@wits.ac.za.
authors.forename: Tanusha
authors.initials: T
authors.lastname: Dukhan
authors.affiliation: Brain Function Research Group, School of Physiology, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg 2193, South Africa. Electronic address: Lois.Harden@wits.ac.za.
authors.forename: Lois M
authors.initials: LM
authors.lastname: Harden
mesh_terms: D000818:Animals; D000855:Anorexia / Q000209:etiology*; D015992:Body Mass Index; D005334:Fever / Q000209:etiology*; D053609:Lethargy / Q000209:etiology*; D008297:Male; D009174:Mycoplasma / Q000472:pathogenicity; D009175:Mycoplasma Infections / Q000150:complications*; D011749:Pyrogens / Q000633:toxicity; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D011749:Pyrogens
keywords: Anorexia; CNS infection; Fear memory; Fever; IL-1β; Lethargy; Mycoplasma; Stunting