Investigation of periaqueductal gray (PAG) in the organization of the defense responses front predator.

Author(s)

Rodrigo de Andrade Rufino

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2016-02-03

Examining board members

Newton Sabino Canteras; Carolina Demarchi Munhoz; Maria Gabriela Menezes de Oliveira

• Advisor: Newton Sabino Canteras

Abstract

First, we investigated the defensive responses of injured animals of the dorsal part of the rostral PAG during predatory confrontation. These animals remained with the risk assessment responses (AR) however lose the freezing of response. In a second study, we analyzed the defensive responses front predator injured animals in the ventrolateral part of the caudal PAG. These animals lose the responses of freezing and increase AR responses. Does the AR responses depend on the integrity of dorsal part rostral and caudal ventrolateral PAG? Finally, we investigated the defensive responses in animals with combined injury of these areas. We observed a dramatic decrease of AR and an increase in exploratory response. Probably AR responses are modulated by the dorsal part of the rostral and caudal ventrolateral PAG through its hypothalamic ascendant targets, and these with the lateral septum. Freezing responses appear to be modulated by descending projections from the PAG to the spinal cord. (AU)

• FAPESP's process: 14/02540-5 - The role the hypothalamic defensive circuit and its main ascending targets on residual fear responses of animals bearing PAGDL lesions during predator exposure
• Grantee: Rodrigo de Andrade Rufino
• Support Opportunities: Scholarships in Brazil - Master