PACAP modulates the consolidation and extinction of the contextual fear conditioning through NMDA receptors

S D Schmidt; J C Myskiw; C R G Furini; B E Schmidt; L E Cavalcante; I Izquierdo

doi:10.1016/j.nlm.2014.11.014

PACAP modulates the consolidation and extinction of the contextual fear conditioning through NMDA receptors

Neurobiol Learn Mem. 2015 Feb:118:120-4. doi: 10.1016/j.nlm.2014.11.014. Epub 2014 Dec 6.

Authors

S D Schmidt¹, J C Myskiw², C R G Furini², B E Schmidt¹, L E Cavalcante¹, I Izquierdo³

Affiliations

¹ Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690, 2nd Floor, 90610-000 Porto Alegre, RS, Brazil.
² Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690, 2nd Floor, 90610-000 Porto Alegre, RS, Brazil; National Institute of Translational Neuroscience (INNT), National Research Council of Brazil, Brazil.
³ Memory Center, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Av. Ipiranga, 6690, 2nd Floor, 90610-000 Porto Alegre, RS, Brazil; National Institute of Translational Neuroscience (INNT), National Research Council of Brazil, Brazil. Electronic address: izquier@terra.com.

PMID: 25490058
DOI: 10.1016/j.nlm.2014.11.014

Abstract

Pituitary adenylate cyclase-activating polypeptide (PACAP) has a broad spectrum of biological functions including neurotransmitter, neurotrophic and neuroprotective. Moreover, it has been suggested that PACAP plays a role in the modulation of learning and memory as well as on the modulation of glutamate signaling. Thus, in the current study we investigated in the CA1 region of hippocampus and in the basolateral amygdala (BLA) the role of PACAP in the consolidation and extinction of contextual fear conditioning (CFC) and the interaction between PACAP and NMDA receptors. Male rats with cannulae implanted in the CA1 region of the hippocampus or in the BLA received immediately after the training or extinction training of the CFC infusions of the Vehicle, PACAP-38 (40 pg/side), PACAP 6-38 (40 pg/side) or PACAP 6-38 plus D-serine (50 μg/side). After 24h, the animals were subjected to a 3-min retention test. The results indicated that in the CA1 region of hippocampus, PACAP participates in the consolidation and extinction of the CFC, and in the BLA, PACAP participates only in the consolidation of the CFC. Additionally, the results suggest that the action of PACAP on the consolidation and extinction of the CFC is mediated by the glutamate NMDA receptors.

Keywords: Consolidation; Contextual fear conditioning; Extinction; NMDA receptors; PACAP.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Basolateral Nuclear Complex / drug effects
Basolateral Nuclear Complex / physiology*
CA1 Region, Hippocampal / drug effects
CA1 Region, Hippocampal / physiology*
Conditioning, Classical / drug effects
Conditioning, Classical / physiology*
Extinction, Psychological / drug effects
Extinction, Psychological / physiology*
Fear / drug effects
Fear / physiology*
Male
Motor Activity / drug effects
Pituitary Adenylate Cyclase-Activating Polypeptide / pharmacology
Pituitary Adenylate Cyclase-Activating Polypeptide / physiology*
Rats
Rats, Wistar
Receptors, N-Methyl-D-Aspartate / physiology*

Substances

Pituitary Adenylate Cyclase-Activating Polypeptide
Receptors, N-Methyl-D-Aspartate