Fear memory modulation by incentive down and up-shifts

MUGNAINI, MATÍAS; ALFEI, JOAQUÍN M.; BUENO, ADRIAN MARCELO; FERRER-MONTI, ROQUE IGNACIO; URCELAY, GONZALO

BEHAVIOURAL BRAIN RESEARCH

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2022 vol. 422 p. 1 - 15

0166-4328

Research on retrieval-induced malleability of maladaptive emotional memories has been mostly focused on theeffect of drugs and extinction (i.e. post-retrieval extinction). Only a few studies addressed post-retrieval appetitive-aversive interactions. Due to the relevance that the understanding of the interactions between memorycontent and appetitive or aversive states under retrieval circumstances has for translational research, here weexplored the relation between fear (i.e. contextual fear conditioning) and sucrose concentration down (32?4%)or up-shifts (4?32%). These have been reported as methods to induce aversive or appetitive internal states,respectively. We observed that fear expression is differentially susceptible to incentive contrast manipulationsdepending on the memory stage: acquisition, mere retrieval or retrieval-induced memory malleability. After fearacquisition, freezing behavior and incentive shift direction followed an inverse relation, that is: up-shiftdecreased fear responding and down-shift increased it. However, freezing behavior remained unaltered whenincentive contrast was absent, regardless of the sucrose concentration employed (4?4% and 32?32%). Whenincentive shifts occurred after mere-retrieval, both negative and positive incentive shifts resulted in increasedfreezing behavior. Strikingly, this effect was unrelated to the nature of the incentive contrast (either positive ornegative), occurring only when animals had no previous experience with the shifted solution. On the other hand,when fear retrieval led to memory malleability, up-shifts in sucrose concentration dampened freezing behavior asmuch as unshifted controls, whilst down-shift left freezing unaltered. Freezing facilitation was finally achievedafter retrieval-induced memory malleability only after prior sampling of the down-shifted solution (i.e. 4% SUC).These results reveal a complex pattern of interactions between memory retrieval and incentive shift-inducedinternal states.