Anatomical connections of the periaqueductal gray: specific neural substrates for different kinds of fear

The periaqueductal gray (PAG) has been traditionally considered to be an exit relay for defensive responses. Functional mapping of its subdivisions has advanced our knowledge of this structure, but synthesis remains difficult mainly because results from lesion and stimulation studies have not correlated perfectly. After using a strategy that combined both techniques and a reevaluation of the available literature on PAG function and connections, we propose here that freezing could be mediated by different PAG subdivisions depending on the presence of immediate danger or exposure to related signaling cues. These subdivisions are separate functional entities with distinct descending and ascending connections that are likely to play a role in different defensive responses. The existence of ascending connections also suggests that the PAG is not simply a final common path for defensive responses. For example, the possibility that indirect ascending connections to the cingulate cortex could play a role in the expression of freezing evoked by activation of the neural substrate of fear in the dorsal PAG has been considered

Anísio Teixeira entre nós: a defesa da educação como direito de todos<A NAME="top1"></A> Anísio Teixeira: defending education as a universal right

O objetivo do artigo é realizar uma reflexão sobre a vida e a obra de Anísio Teixeira (1900-1971), na comemoração do seu centenário de nascimento, destacando momentos decisivos da sua biografia, suas motivações como educador, aspectos da sua apropriação de John Dewey e a atualidade das suas concepções para pensar a educação brasileira contemporânea.<br>The objective this article is to look back on Anísio Teixeira's life and work (1900-1971), on the 100th anniversary of his birth, including decisive moments in his biography, his motivations as an educator, different aspects of his appropriation of John Dewey's work, and the usefulness of his conceptions for reflecting on contemporary Brazilian education