Stress and cognition. Mechanisms regulating memory and empathy

PhD ceremony: Ms. P. Atsak, 16.15 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: Stress and cognition. Mechanisms regulating memory and empathy

Promotor(s): prof. B. Roozendaal, prof. C.M. Keysers

Faculty: Medical Sciences

Stress has multifaceted effects on cognition. It is well known that memories are not created equally, for example emotionally arousing and traumatic life events are consolidated and better remembered. This is an evolutionary important mechanism since it promotes the remembrance of events that are significant for the survival of the organism. On the other hand, stress acutely impairs the retrieval of previously learned information. Daily life examples of this phenomenon could be the difficulty in retrieving information during an important exam or job interview. Prior studies indicated that both effects result from the influences of hormones (glucocorticoids and epinephrine) released from adrenal glands during stressful episodes. Classically, glucocorticoids act through slow genomic pathways involving transcriptional regulation that take hours to emerge, but they can also exert nongenomic actions (not involving transcriptional events) in a rapid fashion. The neurobiological mechanisms that are responsible for mediating these rapid glucocorticoid actions are poorly understood. The findings of this thesis indicate that the endocannabinoid system, a fast-acting lipid system in the brain, mainly known for mediating the psychoactive effects of cannabis, is crucially involved in regulating the rapid effects of glucocorticoids on both the consolidation and retrieval of emotionally arousing experiences. These findings might not only result in the development of new treatment strategies for people with traumatic memories and posttraumatic stress disorder, but may also explain why cannabis is so often used by people suffering from traumatic experiences.