Food restriction does not relieve PTSD-like anxiety

Area of Science:

• Neuroscience
• Behavioral Science
• Endocrinology

Background:

• The inescapable foot shock (IFS) paradigm in rats serves as an animal model for post-traumatic stress disorder (PTSD).
• Previous research indicated exercise can reverse IFS-induced stress sensitivity.
• Food restriction is known to possess antidepressant and anxiolytic properties.

Purpose of the Study:

• To investigate if food restriction reduces anxiety in the IFS model.
• To determine if food restriction acts through a neuropeptide Y (NPY)-dependent mechanism, similar to enrichment.
• To assess the impact of food restriction on anxiety-related behaviors and NPY/Y1 receptor expression in the amygdala.

Main Methods:

• Rats were exposed to the IFS paradigm to model PTSD.
• Anxiety was measured using open field tests (locomotion, freezing) and forced swim tests (immobility, swimming).
• Gene expression of NPY and Y1 receptor in the amygdala was quantified using qPCR after two weeks of food restriction.

Main Results:

• Food restriction slightly increased locomotion and decreased freezing in both control and IFS rats.
• IFS-induced anxiety was not significantly reduced by food restriction.
• Food restriction increased swimming and decreased immobility in IFS rats during the forced swim test.
• Y1 receptor expression in the basolateral amygdala decreased following both IFS and food restriction.

Conclusions:

• Food restriction exhibits a general anxiolytic effect but does not abolish PTSD-like anxiety induced by IFS.
• The anxiolytic effects of food restriction in this model do not appear to be mediated by enhanced Y1 receptor expression.
• The specific pathogenic anxiety associated with IFS is not effectively treated by food restriction via the studied NPY pathway.