Get Past the Past

There is an old drug that has fairly recently been shown to prevent the emotional consequences of memory recall via reconsolidation.   

The drug is Propranolol, a beta blocker that prevents adrenergic stimulation.  Marketed as Inderal, this medication has long been prescribed to control high blood pressure and anxiety. 

Among the fascinating implications, Propranolol administration during the recall of painful memories may speed the habituation(healing) of past traumas, and help abolish chemical addiction. 

Does Depression Cause Neurons to Commit Suicide?

audio/visual version
Sandeep Gautam has a nice post on his blog about the effects of depression on hippocampal cells. 

The story is that chronically high levels of cortisol, a stress hormone, kills these neurons.  Depression leads to elevated average cortisol levels, as lower moods make negative emotional responses, such as anger and anxiety, more severe.  Worse, the hippocampus is also responsible for down-regulating stress levels, the shrinking mass thereof creating an inertia with respect to increases in mood, both short and long term.  So, climbing out of depression is harder, the more severe the depression and the longer its duration.  Fortunately, hippocampal cells are born anew with increased average mood levels over a sufficient period of time, increasing the brain's ability to downregulate stress.

I interpret this as representing the physiological mechanism by which low average mood levels demand higher net levels of reinforcement over the longer term to reduce depression-related risk aversion, in the risk averse.  This serves the behavioral economic purpose of requiring more evidence that an environment long seen as hostile to the goal of secure reproduction has become more hospitable.  This is the equivalent of not trusting someone who is long seen as a jerk, but acts somewhat nicer on a given day.  The trust in the change doesn't come overnight, and nor should a trust in what is normally an inhospitable enviornment.

Duh

"Prozac and Celexa Exhibit Anti-Inflammatory Effects" is the headline in a Science Daily article today. 

This is conclusion is well within my paradigm. My paradigm says that risk aversion increases as mood decreases.  Anxiety, being an expected loss, lowers mood, which is the net rate of intake of reinforcement.  This serves the purpose of minimizing further losses of resource intake necessary for biological functioning.  The subjective value of losses increases, including those involving physical injury, as all gains and losses are translated into mood.

Given evidence, such that anxiety can worsen muscle spasms,which is well-known, and that spasms serve to protect inflamed areas of the body, to protect against further injury and/or facilitate repair, this isn't surprising.  Of course, we also know that stress can lower pain thresholds, conrolling for adrenaline spikes.

This is an example, not only of poor reporting, but of what seems to be the problem in the fields of the study of brain and behavior.  Most researchers don't seem to have an over-arching paradigm, such as the economics of behavior to guide them.