Modulation of defensive responses and anxiety-like behaviors by group I metabotropic glutamate receptors located in the dorsolateral periaqueductal gray - Lima, Vivian C. F.; Molchanov, Moriana L.; Aguiar, Daniele C.; Campos, Alline C.; Guimarães, Francisco Silveira (Progress in Neuro-Psychopharmacology & Biological Psychiatry, 2008)