| Full text | |
| Author(s): |
Oliveira‚ L.C.
;
Nobre‚ M.J.
;
Brandão‚ M.L.
;
Landeira-Fernandez‚ J.
Total Authors: 4
|
| Document type: | Journal article |
| Source: | Neuroreport; v. 15, n. 14, p. 2281, 2004. |
| Abstract | |
The amygdala and ventral portion of the periaqueductal gray (vPAG) are crucial for the expression of the contextual freezing behavior. However, it is still unclear whether the amygdala also plays a role in defensive behaviors induced by electrical stimulation of the dorsal periaqueductal gray (dPAG). In the present study, rats were implanted with electrodes into dPAG for determination of the thresholds for freezing and escape responses before and after sham or electrolytic lesions in the amygdala. Animals were then submitted to a context fear conditioning procedure. Amygdala lesions disrupted contextual freezing but did not affect defensive behaviors induced by dPAG electrical stimulation. These results indicate that contextual and unconditioned freezing behaviors are mediated by independent neural circuits. (AU) | |
| FAPESP's process: | 98/11187-2 - Neurobiology of fear and stress |
| Grantee: | Marcus Lira Brandão |
| Support Opportunities: | Research Projects - Thematic Grants |