Effect of Acute Stress on the Expression of BDNF, trkB, and PSA-NCAM in the Hippocampus of the Roman Rats: A Genetic Model of Vulnerability/Resistance to Stress-Induced Depression.

Maria Serra,Osvaldo Giorgi,Laura Poddighe,Marina Quartu,Marianna Boi,Maria Piludu,Francesco Sanna,Maria Corda,Fabrizio Sanna

doi:10.3390/ijms19123745

Maria Serra, Osvaldo Giorgi + Show 7 more

Open Access

https://doi.org/10.3390/ijms19123745

Copy DOI

Abstract

The Roman High-Avoidance (RHA) and the Roman Low-Avoidance (RLA) rats, represent two psychogenetically-selected lines that are, respectively, resistant and prone to displaying depression-like behavior, induced by stressors. In the view of the key role played by the neurotrophic factors and neuronal plasticity, in the pathophysiology of depression, we aimed at assessing the effects of acute stress, i.e., forced swimming (FS), on the expression of brain-derived neurotrophic factor (BDNF), its trkB receptor, and the Polysialilated-Neural Cell Adhesion Molecule (PSA-NCAM), in the dorsal (dHC) and ventral (vHC) hippocampus of the RHA and the RLA rats, by means of western blot and immunohistochemical assays. A 15 min session of FS elicited different changes in the expression of BDNF in the dHC and the vHC. In RLA rats, an increment in the CA2 and CA3 subfields of the dHC, and a decrease in the CA1 and CA3 subfields and the dentate gyrus (DG) of the vHC, was observed. On the other hand, in the RHA rats, no significant changes in the BDNF levels was seen in the dHC and there was a decrease in the CA1, CA3, and DG of the vHC. Line-related changes were also observed in the expression of trkB and PSA-NCAM. The results are consistent with the hypothesis that the differences in the BDNF/trkB signaling and neuroplastic mechanisms are involved in the susceptibility of RLA rats and resistance of RHA rats to stress-induced depression.

Highlights

It is well-established that stressors may elicit different behavioral and neurochemical adaptive responses in each individual [1,2,3,4,5], depending on the genetically-determined pre-existing differences in temperament, cognition, and autonomic physiology [6]
No significant differences between the lines were found in the other behavioral parameters
In rats submitted to contextual fear conditioning, the levels of polysialic acid (PSA)-neural cell adhesion molecule (NCAM) in the hippocampus, are significantly reduced 24 h after training [68]. Considered together, these findings suggest that the PSA-NCAM plays a role in the effects of stressors involved in both ‘emotional learning’ and spatial learning/memory, corresponding to the different functional involvement of the ventral hippocampus (vHC) and dorsal hippocampus (dHC), in learning experiences

Summary

Introduction

It is well-established that stressors may elicit different behavioral and neurochemical adaptive responses in each individual [1,2,3,4,5], depending on the genetically-determined pre-existing differences in temperament, cognition, and autonomic physiology [6]. Several animal models have been designed to investigate the impact of the interactions between genetic and environmental factors on the neural substrates of depression One of these models, the outbred Roman High-Avoidance (RHA) and the Roman Low-Avoidance (RLA) rats, were selected for rapid (RHA) vs extremely poor (RLA) acquisition of active avoidance, in a shuttle-box [8,9,10]. The RLA rats are more emotional/fearful than the RHA rats in different anxiety-related tasks and display a passive coping strategy, when exposed to aversive situations [4,12,13,14]

Methods

Results

Conclusion