Fear
– I’m So Scared, What’s Going On?!
In
this day and age it seems like an increasingly larger number of people are
claiming to have some sort of anxiety, fear, or phobia. With the internet and
the advancement in technology, it comes as no surprise that people are more
readily exposed to just about everything that ever was in the world. Therefore,
each individual experience may be wrought with a conditioned fear response.
However, where does this fear come from? Why does it appear that our society is
making a trend toward being a worried mother concerned about anything and
everything?
Although
those may be questions too big to answer in one small blog post, the physiology
behind the fear response if fairly well known and can give good insight as to why
people respond to certain fear inducing stimuli in the way that they do. To
begin with, the amygdala, which is about the size of a bean, located deep
within the temporal lobe and attached to the hippocampus, consists of different
neurons that can mediate one’s response to fear. The response can be to trigger
the sympathetic nervous system or eliminate the idea of an irrational response,
which is termed extinction, depending on which part of the basolateral amygdala
is stimulated (Jasnow et al. 2013). The amygdala is crucial in mediating the
conditional fears of an individual, whether that be accepting or exterminating
them. Furthermore, fear is a physiological reaction that has been conserved for
millennia and across many different species, like frogs and sharks, for example
(Logan 2013). It exists as an innate response with which different species use
to increase their fitness. Why then do different individuals experience such a
wide array of fears and why do some of them make absolutely no sense? Insane fears
and phobias, like that of spiders or small spaces, are conditioned responses
controlled by the amygdala. Such types of fears may be able to succumb to
manipulation via certain types of alterations to the amygdala via chemical
lesions (Isumi et al. 2012). Similar results could give further insight into
our understanding of being frightened and could lead to a more efficient means
of eliminating irrational, unwanted fears that can potentially inhibit everyday activities.
References:
Isumi T, Ohmura Y, Ftuami Y, Matsuzaki
H, Kubo Y, Yoshida T, Yoshioka M. Effects of
Serotonergic
Terminal Lesion in the Amygdala on Conditioned Fear and Innate Fear in Rats. European Journal of Pharmacology
696(1-3): 89-95, Dec. 2012.
Jasnow AM, Ehrlich DE, Choi DC,
Dabrowska J, Bowers ME, McCullough KM, Rainnie
DG,
Ressler KJ.
Thy1-Expressing Neurons in the Basolateral Amygdala May Mediate Fear
Inhibition. The Journal of Neuroscience 33(25):
10396-10404, June 2013.
Logan C. 4 Nov. 2013. Creighton Prof Probes Bevy of Brains
to Find What Gives Us Fright
[Online]. Omaha
World-Herald.
http://www.omaha.com/article/20131104/LIVING/131109624/1696#creighton-prof-probes-bevy-of-brains-to-find-what-gives-us-fright
[4 Nov. 2013].
What are the chemical pathways of anxiety and fears? Can we target therapeutics that can block or enhance certain receptors and transmitters in the brain and in the amygdala region? I was thinking about how serotonin reuptake inhibitors can help in fighting phobias. Would it be similar in how SSRIs treat general anxiety disorder and depression?
ReplyDeleteInteresting post. I think you hit on a really big divide within the psychological and scientific communities regarding fear when you called it a conditioned response--which implies that you believe that fear/anxiety are behavioral in nature (am I interpreting that correctly?). While I do agree that parts of it can be conditioned--e.g. the particular fears to things such as spiders--I also think that a lot of it is biological in nature. From what I have read, the divide has narrowed in recent years, with a lot of research into the causes of mental illnesses (at least the research funded by the NIMH) investigating the complex interplay between nature and nurture (genetics, neurobiology, etc., and phenomena such as conditioning). The NIMH funds research into the biological (both neurological and genetic) as well as the behavioral (the conditioning aspect) of psychological disorders, and they now say that mental illnesses (including phobias) are studied as neurological disorders, with genetics and environmental, experiential, and developmental influences (such as trauma--e.g. child abuse, war, etc.) interacting a way that leads to the anxiety disorders. The role that conditioning could play in that environmental piece is definitely interesting; however, I think the chemical pathways BillyT618 brought up also play a really big role.
ReplyDeleteNational Institute of Mental Health. (2008). NIMH Vision. Retrieved from http://www.nimh.nih.gov/about/strategic-planning-reports/index.shtml