Effect of functional disconnection between hippocampus and pre-limbic cortex on the acquisition of contextual fear conditioning and contextual fear conditioning with temporal discontinuity

• Grant number: 17/25917-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2018
• End date: December 31, 2018
• Field of knowledge: Biological Sciences - Pharmacology - Neuropsychopharmacology
• Principal Investigator: Maria Gabriela Menezes de Oliveira
• Grantee: Andreia Eleutério Wallau
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

Stimuli to be associated frequently overlap, but it is also possible to associate stimuli discontinuously in time, as shown in trace conditioning for a discrete stimulus. It is thought that this learning requires the brain to continue representing the stimulus after its presentation and that it involves the pre-limbic cortex (PL). As the environment is also a powerful CS and is inevitably associated to the stimuli that occur in it, it may also be subject to trace fear conditioning. Recent work on our research group tested this hypothesis. We showed that a contextual representation can be maintained and associated to an aversive stimulus after 5s of temporal and spatial discontinuity, requiring PL activity, differently from contextual fear conditioning (CFC), in which stimuli overlap. To better understand how a contextual representation remains in a temporal interval and is associated to a posterior aversive stimulus, the present study aims to investigate the requirement of interactions of PL (related to maintain information over time) with hippocampus (related to form a contextual representation) on CFC with temporal and spatial discontinuity. As there are ascending ipsilateral monosynaptic connections between the hippocampus and PL, we will explore this question by a functional disconnection between PL and hippocampus by asymmetric pharmacological inactivation using GABA A agonist muscimol. The disconnection will be performed before the training. For comparison, the functional disconnection will also be performed in animals trained in the CFC task. This study intends to allow a better understanding of the influence of a spatial and temporal discontinuity in the neurobiology and functional interactions of regions underlying CFC acquisition. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SANTOS, THAYS BRENNER; WALLAU, ANDREIA ELEUTERIO; KRAMER-SOARES, JULIANA CARLOTA; MENEZES OLIVEIRA, MARIA GABRIELA. Functional interaction of ventral hippocampal CA1 region and prelimbic cortex contributes to the encoding of contextual fear association of stimuli separated in time. NEUROBIOLOGY OF LEARNING AND MEMORY, v. 171, MAY 2020. (17/25917-5, 16/13027-2, 16/25755-2)