AN INTRACEREBROVENTRICULAR INJECTION OF AMYLOID BETA PEPTIDE MODIFIED TEMPORAL PATTERNS OF COGNITIVE FUNCTIONS, CREB, RAR AND RXR EXPRESSION IN HIPPOCAMPUS RAT

CORTEZ M; CORIA-LUCERO C; LEDEZMA, C; GOLINI RS; RODRIGUEZ A; SCOLLO G; ALBA R; DELGADO SM; ANZULOVICH AC; NAVIGATORE FONZO LS

San Juan

Congreso; SBCuyo 2023; 2023

Alzheimer's dementia (AD) is a neurodegenerative disorder that causes memory loss and dementia in older adults.Memory and learning-related genes such as Creb (cAMP response element binding protein), Bdnf (Brain-derivedneurotrophic factor) and its receptor TrkB, have been detected in the hippocampus. It is well known RARs and RXRsreceptors function as transcription factors on retinoid-responsive target genes. In addition to memory loss, Alzheimer'spatients have circadian rhythm dysfunction. Previously, we have demonstrated that an intracerebroventricular injectionof A (1-42) modified the daily rhythms of cognition-related factors (Bdnf/TrkB) in the rat hippocampus. Continuingwith that study, the objective of this work was to evaluate the consequences of an intracerebroventricular injection of A(1-42) on temporal patterns of cognitive performance, as well as on Creb, RAR and RXR expression in thehippocampus of A -injected rats. Four-month-old males Holtzman rats were divided into two groups defined as: 1)control 2) A -injected. Rats were maintained under 12h-Light:12h-Dark conditions. The cognition ability was evaluatedusing object location test. Creb, RAR and RXR transcript levels were determined by RT-PCR in hippocampus samplesisolated every 6 hs. We found that an intracerebroventricular injection of Aß aggregates impaired learning and memoryin rats and modified daily patterns of Creb, RAR and RXR in the rat. Our findings showed that the increase of Aßaltered temporal patterns of RAR and RXR , and, consequently, induced alterations in daily rhythms of clock-relatedfactors, affecting the cognitive performance of animals with Alzheimer's.