Inactivation of the dorsolateral periaqueductal gray matter impairs the promoting influence of stress on fear memory during retrieval

GIACHERO, MARCELO; PAVESI, ELOISA; CALFA, GASTÓN; MOTTA, SIMONE C.; CANTERAS, NEWTON S.; MOLINA, VÍCTOR A.; CAROBREZ, ANTONIO P.

BRAIN STRUCTURE & FUNCTION

SPRINGER HEIDELBERG

Año: 2019

1863-2653

xposure to stressful conditions induces long-lasting neurobiological changes in selected brain areas, which could be associated with the emergence of negative emotional responses. Moreover, the interaction of a stressful experience and the retrieval of an established fear memory trace enhance both fear expression and fear retention. Related to this, the stimulation of the dorsolateral part of the mesencephalic periaqueductal gray matter (dlPAG) prior to retrieval potentiates a fear memory trace previously acquired. Therefore, the question that arises is whether the dlPAG mediates the increased fear expression and fear retention after retrieval. Rats were subjected to a contextual fear conditioning paradigm using a single footshock, and 1 day later, rats were subjected to a stressful situation. As previously reported, there was an increase of freezing response only in those rodents that were re-exposed to the associated context at 1 and 5 days after stress exposure. Muscimol intra