Dorsal periaqueductal gray stimulation facilitates anxiety-, but not panic-related, defensive responses in rats tested in the elevated T-maze
AUTOR(ES)
Camplesi Jr, M., Bortoli, V.C.de, Soares, V. de Paula, Nogueira, R.L., Zangrossi Jr., H.
FONTE
Braz J Med Biol Res
DATA DE PUBLICAÇÃO
2012-11
RESUMO
The escape response to electrical or chemical stimulation of the dorsal periaqueductal gray matter (DPAG) has been associated with panic attacks. In order to explore the validity of the DPAG stimulation model for the study of panic disorder, we determined if the aversive consequences of the electrical or chemical stimulation of this midbrain area can be detected subsequently in the elevated T-maze. This animal model, derived from the elevated plus-maze, permits the measurement in the same rat of a generalized anxiety- and a panic-related defensive response, i.e., inhibitory avoidance and escape, respectively. Facilitation of inhibitory avoidance, suggesting an anxiogenic effect, was detected in male Wistar rats (200-220 g) tested in the elevated T-maze 30 min after DPAG electrical stimulation (current generated by a sine-wave stimulator, frequency at 60 Hz) or after local microinjection of the GABA A receptor antagonist bicuculline (5 pmol). Previous electrical (5, 15, 30 min, or 24 h before testing) or chemical stimulation of this midbrain area did not affect escape performance in the elevated T-maze or locomotion in an open-field. No change in the two behavioral tasks measured by the elevated T-maze was observed after repetitive (3 trials) electrical stimulation of the DPAG. The results indicate that activation of the DPAG caused a short-lived, but selective, increase in defensive behaviors associated with generalized anxiety.
Documentos Relacionados
- Effects of emotional reactivity on inhibitory avoidance in the elevated T-maze
- The effects of diazepam on the elevated T-maze are dependent on the estrous cycle of rats
- Lesion of the Ventral Periaqueductal Gray Reduces Conditioned Fear but Does Not Change Freezing Induced by Stimulation of the Dorsal Periaqueductal Gray
- Critical neuropsychobiological analysis of panic attack- and anticipatory anxiety-like behaviors in rodents confronted with snakes in polygonal arenas and complex labyrinths: a comparison to the elevated plus- and T-maze behavioral tests
- Glucose injections into the dorsal hippocampus or dorsolateral striatum of rats prior to T-maze training: Modulation of learning rates and strategy selection