Effects of altered amygdalar neuropeptide Y expression on anxiety-related behaviors.
Neuropeptide Y (NPY) decreases anxiety-related behaviors in various animal models of anxiety. The purpose of the present study was to examine the role of the amygdalar NPY system in anxiety-related responses in the elevated plus maze. The first experiment determined if herpes virus-mediated alterations in amygdalar NPY levels would alter anxiety-related behaviors in the elevated plus maze. Viral vectors encoding NPY, NPY antisense, or LacZ (control virus) were bilaterally injected into the amygdala, and 4 days postinjection, rats were tested in the elevated plus maze test. NPY-like immunoreactivity (NPY-ir) was measured in the amygdala of these rats. In rats injected with the viral vector encoding NPY, reduced anxiety-related behaviors in the elevated plus maze accompanied by moderate increases in NPY-ir were detected compared to NPY-antisense viral vector-treated subjects. Elevated plus maze behavior did not differ compared to LacZ-treated controls. NPY overexpression at this time point was also suggested by enhanced NPY mRNA expression seen in the amygdala 4 days postinjection using real-time polymerase chain reaction analysis. Experiment 2 was conducted to provide further evidence for a role of amygdalar NPY in regulating anxiety-related behaviors in the elevated plus maze test. The nonpeptide NPY Y1 receptor antagonist, BIBP 3226 (1.5 microg/microl), was bilaterally injected into the amygdala and rats were tested in the elevated plus maze test. Rats receiving BIBP 3226 exhibited increased anxiety-related behaviors in this test. The results of these experiments provide further support for the role of amygdalar NPY in anxiety-related behaviors.
Primeaux
Stefany D
SD
Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA. PrimeaSD@pbrc.edu
Wilson
Steven P
SP
Cusick
Michael C
MC
York
David A
DA
Wilson
Marlene A
MA
D000679:Amygdala / Q000187:drug effects / Q000378:metabolism* / Q000821:virology; D000818:Animals; D014151:Anti-Anxiety Agents / Q000627:therapeutic use; D001007:Anxiety / Q000503:physiopathology* / Q000628:therapy; D001120:Arginine / Q000031:analogs & derivatives / Q000627:therapeutic use; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D016373:DNA, Antisense / Q000627:therapeutic use; D004195:Disease Models, Animal; D005786:Gene Expression Regulation / Q000502:physiology*; D005822:Genetic Vectors / Q000502:physiology; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology; D009478:Neuropeptide Y / Q000096:biosynthesis / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D020318:Rats, Long-Evans; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013997:Time Factors
D014151:Anti-Anxiety Agents; C092926:BIBP 3226; D016373:DNA, Antisense; D009478:Neuropeptide Y; D012333:RNA, Messenger; D001120:Arginine