Alteration of FDG uptake by performing novel object recognition task in a rat model of Traumatic Brain Injury

Abstract

Traumatic Brain Injury (TBI) affects approximately 2.5 million people in the United States, of which 80% are considered to be mild (mTBI). Previous studies have shown that cerebral glucose uptake and metabolism are altered after brain trauma and functional metabolic deficits observed following mTBI are associated with changes in cognitive performance. Imaging of glucose uptake using [ 18 F] Fluorodeoxyglucose (FDG) based Positron Emission Tomography (PET) with anesthesia during the uptake period demonstrated limited variability in results, but may have depressed uptake. Anesthesia has been found to interfere with blood glucose levels, and hence, FDG uptake. Conversely, forced cognitive testing during uptake may increase glucose demand in targeted regions, such as hippocampus, allowing for better differentiation of outcomes. Therefore, the objective of this study was to investigate the influence of a directed cognitive function task during the FDG uptake period on uptake measurements both in naïve rats and at 2 days after mild lateral fluid percussion (mLFP) TBI. Adult male Sprague Dawley rats underwent FDG uptake with either cognitive testing with the Novel Object Recognition (NOR) test or No Novel Object (NNO), followed by PET scans at baseline (prior to injury) and at 2days post mLFP. At baseline, FDG uptake in the right hippocampus was elevated in rats completing the NOR in comparison to the NNO (control group). Further, the NNO group rats demonstrated a greater fold change in the FDG uptake between baseline and post injury scans than the NOR group. Overall, these data

Maternal Immune Activation Induces Cortical Catecholaminergic Hypofunction and Cognitive Impairments in Offspring

“…Recognition memory refers to the ability to judge a previous encountered item as familiar. The NORT is a behavioral test that uses novelty to evaluate time spent with a novel object versus a familiar object, as a measure of spatial and visual learning and memory evocation capacity [ 53 ]. This test consists of four consecutive days of experimental trials: a first day for habituation, two days of training and the last day for testing.…”

Fundamental Neurochemistry Review: Microglial immunometabolism in traumatic brain injury

“…[18]F‐fluorodeoxyglucose (FDG) positron emission tomography (PET) neuroimaging in humans and animal models has identified significant TBI‐induced changes in brain glucose metabolism (Brabazon et al, 2017; Byrnes et al, 2014; Jaiswal et al, 2019; Okonkwo et al, 2019; Yasmin et al, 2022). In pre‐clinical models, TBI produces divergent effects in FDG uptake according to injury severity and time post‐injury.…”