Fear-context association during memory retrieval requires input from granular to dysgranular retrosplenial cortex

SIGWALD, ERIC L.; BIGNANTE, ELENA A.; DE OLMOS, SOLEDAD; LORENZO, ALFREDO

NEUROBIOLOGY OF LEARNING AND MEMORY

ACADEMIC PRESS INC ELSEVIER SCIENCE

Año: 2019 vol. 163

1074-7427

he contribution of the granular (area 29, A29) and dysgranular (area 30, A30) subdivisions of the retrosplenial cortex (RSC) to contextual fear memory (CFM) retrieval remains elusive. Here, intact and orchiectomized (ORC) male rats received an intraperitoneal (I.P.) injection of saline (control) or 5 mg/Kg MK801 after training and memory formation. In ORC, but not in intact males, this MK801 treatment selectively induces overt loss of neurons in layers IV-Va of A29 (A29MK801 neurons) (Sigwald et al., 2016). Compared to ORC-saline, ORC-MK801 rats showed impaired CFM retrieval in an A-B-A design for contextual fear conditioning (CFC), however context recognition was not affected. In ORC-MK801 rats, neither novel object recognition nor object-in-context discrimination were impaired, further indicating that A29MK801 neurons are not required for contextual recognition. Elevated plus maze test showed that anxiety-like behavior was not affected in ORC-MK801 animals, suggesting that loss of A