TY  - JOUR
PY  - 2015//
TI  - Serotonin in the dorsal periaqueductal gray inhibits panic-like defensive behaviors in rats exposed to acute hypoxia
JO  - Neuroscience
A1  - Spiacci Junior, Ailton
A1  - Sergio, Thatiane de Oliveira
A1  - Ferreira da Silva, Glauber Santos
A1  - Glass, Mogens Lesner
A1  - Schenberg, Luiz Carlos
A1  - Garcia-Cairasco, Norberto
A1  - Junior, Hélio Zangrossi
SP  - 191
EP  - 198
VL  - 307
IS  - 
N2  - It has been proposed that spontaneous panic attacks are the outcome of the misfiring of an evolved suffocation alarm system. Evidence gathered in the last year is suggestive that the dorsal periaqueductal gray (dPAG) in the midbrain harbors a hypoxia-sensitive suffocation alarm system. We here investigated whether facilitation of 5-HT-mediated neurotransmission within the dPAG changes panic-like defensive reactions expressed by male Wistar rats submitted to a hypoxia challenge (7% O2), as observed in other animal models of panic. Intra-dPAG injection of 5-HT (20 nmol), 8-OH-DPAT (8 nmol), a 5-HT1A receptor agonist, or DOI (16 nmol), a preferential 5-HT2A agonist, reduced the number of upward jumps directed to the border of the experimental chamber during hypoxia, interpreted as escape attempts, without affecting the rats' locomotion. These effects were similar to those caused by chronic, but not acute, intraperitoneal administration of the antidepressant fluoxetine (5 -15 mg/kg), or acute systemic administration of the benzodiazepine receptor agonist alprazolam (1 - 4 mg/kg), both drugs clinically used in the treatment of panic disorder. Our findings strengthen the view that the dPAG is a key encephalic area involved in the defensive behaviors triggered by activation of the suffocation alarm system. They also support the use of hypoxia-evoked escape as a model of respiratory-type panic attacks.<p /> <p>Language: en</p>
LA  - en
SN  - 0306-4522
UR  - http://dx.doi.org/10.1016/j.neuroscience.2015.08.045
ID  - ref1
ER  -