Activation of a remote (1-year old) emotional memory interferes with the retrieval of a newly formed hippocampus-dependent memory in rats.

The persistent intrusion of remote traumatic memories in people with post-traumatic stress disorder (PTSD) may contribute to the impairment of their ongoing hippocampal and prefrontal cortical functioning. In the current work, we have developed a rodent analogue of the intrusive memory phenomenon. We studied the influence of the activation of a remote traumatic memory in rats on their ability to retrieve a newly formed hippocampus-dependent memory.

Acute stress-induced impairment of spatial memory is associated with decreased expression of neural cell adhesion molecule in the hippocampus and prefrontal cortex.

Background: There is an extensive literature describing how stress disturbs cognitive processing and can exacerbate psychiatric disorders. There is, however, an insufficient understanding of the molecular mechanisms involved in stress effects on brain and behavior.

Methods: Rats were given spatial memory training in a hippocampus-dependent water maze task.