Here are a few things that happen to the very cells (in the hippocampus) that you rely on:
– reorganization within mossy fiber terminals
– loss of excitatory glutamatergic synapses
– reduction in the surface area of postsynaptic densities
– marked retraction of thorny excrescences
– alterations in the lengths of the terminal dendritic segments of pyramidal cells
– reduction of the dorsal anterior CA1 area volume
Thanks brain! Thanks neurons for abandoning me when I need you most! According to this article, these cellular changes lead to, “impaired hippocampal involvement in episodic, declarative, contextual and spatial memory – likely to debilitate an individual’s ability to process information in new situations and to make decisions about how to deal with new challenges.” UGH!
Are our cells making these changes for a reason? Might it be better for cells to remodel temporarily rather than suffer permanent, life-long damage? Perhaps. Perhaps there are molecular pathways that can lead the reversal of these allostatic stress adaptations?
Check out this recent paper: “A negative regulator of MAP kinase causes depressive behavior” [doi 10.1038/nm.2219] the authors have identified a gene – MKP-1 – a phosphatase that normally dephosphorylates various MAP kinases involved in cellular growth, that, when inactivated in mice, produces animals that are resistant to chronic unpredictable stress. Although its known that MKP-1 is needed to limit immune responses associated with multi-organ failure during bacterial infections, the authors suggest:
“pharmacological blockade of MKP-1 would produce a resilient of anti-depressant response to stress”
Hmmm … so Mother Nature is using the same gene to regulate the immune response (turn it off so that it doesn’t damage the rest of the body) and to regulate synaptic growth (turn it off – which is something we DON’T want to do when we’re trying to recover from chronic stress)? Mother Nature gives us MKP-1 so I can survive an infection, but the same gene prevents us from recovering (finding happiness) from stress?
Of course, we do not need to rely only on pharmacological solutions. Exercise & social integration are cited by these authors as the top 2 non-medication strategies.