Cerebral Blood Flow in Predator Stress-Resilient and -Susceptible Rats and Mechanisms of Resilience

Abstract

Stress-induced conditions are associated with impaired cerebral blood flow (CBF) and increased risk of dementia and stroke. However, these conditions do not develop in resilient humans and animals. Here the effects of predator stress (PS, cat urine scent, ten days) on CBF and mechanisms of CBF regulation were compared in PS-susceptible (PSs) and PS-resilient (PSr) rats. Fourteen days post-stress, the rats were segregated into PSs and PSr groups based on a behavior-related anxiety index (AI). CBF and its endothelium-dependent changes were measured in the parietal cortex by laser Doppler flowmetry. The major findings are: (1) PS susceptibility was associated with reduced basal CBF and endothelial dysfunction. In PSr rats, the basal CBF was higher, and endothelial dysfunction was attenuated. (2) CBF was inversely correlated with the AI of PS-exposed rats. (3) Endothelial dysfunction was associated with a decrease in eNOS mRNA in PSs rats compared to the PSr and control rats. (4) Brain dopamine was reduced in PSs rats and increased in PSr rats. (5) Plasma corticosterone of PSs was reduced compared to PSr and control rats. (6) A hypercoagulation state was present in PSs rats but not in PSr rats. Thus, potential stress resilience mechanisms that are protective for CBF were identified.

Limited Cheese Intake Paradigm Replaces Patterns of Behavioral Disorders in Experimental PTSD: Focus on Resveratrol Supplementation

“…It is well-known that the NAc is a dopaminergic nucleus. In our experimental model of PTSD, we previously observed a decrease in DA concentration in some brain regions, such as the hippocampus and hypothalamus [ 20 , 40 ]. Recently, it has been demonstrated that decreased DA concentration in the brain in PTSD-susceptible rats is associated with a reduction in cerebral blood flow [ 40 ].…”

“…In our experimental model of PTSD, we previously observed a decrease in DA concentration in some brain regions, such as the hippocampus and hypothalamus [ 20 , 40 ]. Recently, it has been demonstrated that decreased DA concentration in the brain in PTSD-susceptible rats is associated with a reduction in cerebral blood flow [ 40 ]. Low DA levels are generally associated with an increased risk for PTSD, and this state is genetically predetermined [ 41 ].…”

A diabetes-like biochemical and behavioural phenotype of Drosophila induced by predator stress

“…Finally, metabolic disorders are often associated with the impairment and loss of dopaminergic function [ 79 ]. Predator-induced stress affects the levels of brain dopamine, which are decreased in rats exposed to predator stress [ 80 , 81 ]. Since the w 1118 strain has reduced dopaminergic activity, the interconnected serotonin and dopamine pathways should be studied simultaneously in predator-induced stress.…”

Unveiling the Link: Exploring Mitochondrial Dysfunction as a Probable Mechanism of Hepatic Damage in Post-Traumatic Stress Syndrome

“…Control rats were housed under similar conditions for the same period under stress-free conditions. This experimental model of PTSD was developed by Cohen [ 14 ] and has been used in many subsequent studies of experimental PTSD [ 12 , 13 ]. The model is based on the well-known fear response of rodents to a predator and its smell.…”

“…Predator stress is considered a well-validated animal model for post-traumatic stress disorder (PTSD) [ 11 , 12 , 13 , 14 , 15 ]. Following PS exposures, rats can be segregated into high anxiety (HA) and low anxiety (LA) phenotypes [ 16 ].…”