title: In a rat model of panic, corticotropin responses to dorsal periaqueductal gray stimulation depend on physical exertion.
abstract: Panic disorder patients are exquisitely and specifically sensitive to hypercapnia. The demonstration that carbon dioxide provokes panic in fear-unresponsive amygdala-calcified Urbach-Wiethe patients emphasizes that panic is not fear nor does it require the activation of the amygdala. This is consonant with increasing evidence suggesting that panic is mediated caudally at midbrain's dorsal periaqueductal gray matter (DPAG). Another startling feature of the apparently spontaneous clinical panic is the counterintuitive lack of increments in corticotropin, cortisol and prolactin, generally considered 'stress hormones'. Here we show that the stress hormones are not changed during DPAG-evoked panic when escape is prevented by stimulating the rat in a small compartment. Neither did the corticotropin increase when physical exertion was statistically adjusted to the same degree as non-stimulated controls, as measured by lactate plasma levels. Conversely, neuroendocrine responses to foot-shocks were independent from muscular effort. Data are consonant with DPAG mediation of panic attacks.
authors.affiliation: Deparment of Physiological Sciences, Federal University of Espírito Santo, Vitória, ES, Brazil.
authors.forename: Rubia
authors.initials: R
authors.lastname: de Souza Armini
authors.affiliation: Deparment of Physiological Sciences, Federal University of Espírito Santo, Vitória, ES, Brazil.
authors.forename: Cristian Setúbal
authors.initials: CS
authors.lastname: Bernabé
authors.affiliation: Deparment of Physiological Sciences, Federal University of Espírito Santo, Vitória, ES, Brazil.
authors.forename: Caroline Azevedo
authors.initials: CA
authors.lastname: Rosa
authors.affiliation: Deparment of Physiological Sciences, Federal University of Espírito Santo, Vitória, ES, Brazil.
authors.forename: Carlos Antônio
authors.initials: CA
authors.lastname: Siller
authors.affiliation: Deparment of Physiological Sciences, Federal University of Espírito Santo, Vitória, ES, Brazil.
authors.forename: Fagna Giacomin
authors.initials: FG
authors.lastname: Schimitel
authors.affiliation: Department of Psychobiology, Federal University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Sérgio
authors.initials: S
authors.lastname: Tufik
authors.affiliation: Phyllis Green and Randolph Cowen Institute for Pediatric Neuroscience, Department of Child and Adolescent Psychiatry, New York University Langone Medical Center, USA; The Nathan S. Kline Institute for Psychiatric Research, USA; Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, NY, USA.
authors.forename: Donald Franklin
authors.initials: DF
authors.lastname: Klein
authors.affiliation: Deparment of Physiological Sciences, Federal University of Espírito Santo, Vitória, ES, Brazil. Electronic address: luiz.schenberg@gmail.com.
authors.forename: Luiz Carlos
authors.initials: LC
authors.lastname: Schenberg
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000818:Animals; D001522:Behavior, Animal; D003345:Corticosterone / Q000097:blood*; D004195:Disease Models, Animal; D004558:Electric Stimulation; D004924:Escape Reaction; D006854:Hydrocortisone / Q000097:blood; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010200:Panic / Q000502:physiology*; D016584:Panic Disorder / Q000097:blood*; D010487:Periaqueductal Gray; D005082:Physical Exertion / Q000502:physiology*; D011388:Prolactin / Q000097:blood*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D019344:Lactic Acid; D000324:Adrenocorticotropic Hormone; D011388:Prolactin; D003345:Corticosterone; D006854:Hydrocortisone
keywords: Corticosterone; Corticotropin; Panic attack; Periaqueductal gray matter; Prolactin; Stress