title: Prelimbic prefrontal cortex mediates respiratory responses to mild and potent prolonged, but not brief, stressors.
abstract: The prefrontal cortex is one of the key areas of the central mechanism of cardiovascular and respiratory control. Disinhibition of the prelimbic medial prefrontal cortex elicits tachypnoeic responses in anesthetized rats (Hassan et al., J. Physiol. 591: 6069-6088, 2013). The current study examines the effects of inhibition of the prelimbic prefrontal cortex during presentation of stressors of various lengths and intensities in conscious unrestrained rats. 8 Wistar rats were implanted with bilateral guide cannulas targeting the prelimbic prefrontal cortex and received microinjections of either saline of GABAA agonist muscimol prior to recording sessions. Inhibition of the prelimbic prefrontal cortex significantly attenuated respiratory responses to a novel environment stress, 30s light stimulus and restraint stress. It did not affect respiratory responses to 500 ms acoustic stimuli of varying intensities (40-90 dB). We conclude that the prelimbic prefrontal cortex contributes to generation of tachypnoeic responses to prolonged stressors, but does not contribute to respiratory arousal in response to brief stressors.
authors.affiliation: School of Biomedical Sciences, University of Newcastle, Callaghan, NSW 2308, Australia; Laboratory of Neuroimmunology, School of Psychology, University of Newcastle, Callaghan, NSW 2308, Australia. Electronic address: Evgeny.Bondarenko@newcastle.edu.au.
authors.forename: E
authors.initials: E
authors.lastname: Bondarenko
authors.affiliation: Laboratory of Neuroimmunology, School of Psychology, University of Newcastle, Callaghan, NSW 2308, Australia.
authors.forename: D M
authors.initials: DM
authors.lastname: Hodgson
authors.affiliation: School of Biomedical Sciences, University of Newcastle, Callaghan, NSW 2308, Australia.
authors.forename: E
authors.initials: E
authors.lastname: Nalivaiko
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D000818:Animals; D002408:Catheters, Indwelling; D004195:Disease Models, Animal; D058785:GABA-A Receptor Agonists / Q000494:pharmacology; D008297:Male; D008845:Microinjections; D009118:Muscimol / Q000494:pharmacology; D010775:Photic Stimulation / Q000379:methods; D010991:Plethysmography; D017397:Prefrontal Cortex / Q000187:drug effects / Q000503:physiopathology*; D017208:Rats, Wistar; D011963:Receptors, GABA-A / Q000378:metabolism; D012119:Respiration / Q000187:drug effects; D012149:Restraint, Physical; D013315:Stress, Psychological / Q000188:drug therapy / Q000503:physiopathology*; D059246:Tachypnea / Q000188:drug therapy / Q000503:physiopathology; D013997:Time Factors
chemical_list: D058785:GABA-A Receptor Agonists; D011963:Receptors, GABA-A; D009118:Muscimol
keywords: Arousal; Medial prefrontal cortex; Prelimbic prefrontal cortex; Respiratory rate; Stress; Tidal volume