Escapable and inescapable stress differentially and selectively alter extracellular levels of 5-HT in the ventral hippocampus and dorsal periaqueductal gray of the rat.
The effects of escapable and yoked inescapable electric tailshocks on extracellular levels of serotonin (5-HT) in the ventral hippocampus and dorsal periaqueductal gray (dPAG) were measured by in vivo microdialysis. Inescapable, but not escapable shock increased extracellular 5-HT in the ventral hippocampus relative to restrained controls. Basal levels of 5-HT were elevated 24 h after inescapable shock, and previously inescapably shocked subjects exhibited an exaggerated 5-HT response to 2 brief footshocks. In contrast, escapable, but not inescapable shock, increased extracellular 5-HT in the dPAG, increased basal 5-HT in the dPAG 24 h later, and led to an enhanced 5-HT response to subsequent brief footshock.
Amat
J
J
Instituto de Medicina Experimental, Universidad Central de Venezuela, Caracas, Venezuela.
Matus-Amat
P
P
Watkins
L R
LR
Maier
S F
SF
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D005110:Extracellular Space / Q000378:metabolism; D006380:Helplessness, Learned; D006624:Hippocampus / Q000378:metabolism*; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D008297:Male; D017551:Microdialysis; D010487:Periaqueductal Gray / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000378:metabolism*; D013312:Stress, Physiological / Q000378:metabolism*
D012701:Serotonin; D006897:Hydroxyindoleacetic Acid