The neurobiology of fear

Bill Glasheen · Post by **Bill Glasheen** » Wed Oct 02, 2002 2:33 pm

This should add to what you might be thinking, Allen. On the issue of how exercise reduces our anxiety and increases our wellbeing, here's evidence that endogenous endorphins and enkephalins are the source. <BLOCKQUOTE>quote:<HR>Int J Sports Med 2002 Apr;23(3):155-7

Opioid receptor blockade eliminates mood effects of aerobic gymnastics.

Jarvekulg A, Viru A.

Institute of Exercise Biology, University of Tartu, Estonia.

The contribution of opioid receptors to the mood effects of aerobic gymnastics was tested by oral administration of naltrexone (25 or 50 mg) in 12 healthy women (aged 22 - 30 years). The opioid receptor blockade eliminated decreased anxiety, negative affect level and depressiveness as well as increased positive affect level, as found in a placebo trial after a 50 min session of aerobic gymnastics. 50 mg of naltrexone was more effective than 25 mg. Administration of 50 mg of naltrexone without exercise did not cause any significant changes in anxiety, positive and negative affect levels or depressiveness.<HR></BLOCKQUOTE> I've always been fascinated by the Uechi conditioning exercises and their role in endorphin release. Check this out. <BLOCKQUOTE>quote:<HR>Pain 2002 Sep;99(1-2):207

Naloxone increases pain induced by topical capsaicin in healthy human volunteers.

Anderson W, Sheth R, Bencherif B, Frost J, Campbell J.

Department of Neurosurgery, School of Medicine, Johns Hopkins University, Meyer 5-109, 600 N. Wolfe Street, 21287-0817, Baltimore, MD, USA

Opioid receptors occur in locations of strategic importance within the central nervous system for modulation of pain. Is pain reduced by ongoing inhibition mediated by activation of these receptors? Experiments to date in which the opioid-receptor antagonist, naloxone, is administered during a painful event have yielded unclear results. Topically applied capsaicin can be used to induce tonic pain of moderate to severe intensity without tissue injury and is an ideal stimulus for studying acute pain modulation. We therefore conducted a placebo-controlled double-blind crossover study to investigate the effects of naloxone on capsaicin-induced pain (five men, four women, aged 29+/-5 years). Capsaicin (10%) was applied topically and subjects rated pain every 2min. The subjects were told that any drug given to them could increase, decrease, or not change their pain sensation. Pain plateaued after 20min. At 26min subjects received either naloxone or placebo in double-blind fashion. At 56min subjects received the alternative (placebo or naloxone). In a second session the order of presentation was reversed. The naloxone induced a significant increase in pain compared both to baseline (P<0.01) and placebo (P<0.01). The peak effect, reached at 12-20min after naloxone delivery, was 59% greater than placebo. This experiment suggests that acute pain is actively suppressed by endogenous opioid-receptor activation.<HR></BLOCKQUOTE> And where there is pain reduction, there is attitude change. The fear opioid receptors get those free-floating endorphins too.

We often talk about "the placebo effect" when reviewing the efficacy of "alternative" medical therapies. Why do folks believe they get a benefit from something that shows no value in a randomized controlled trial? Well belief has a lot to do with it, and it's something modern medicine should take advantage of. Furthermore, it has a biochemical basis. <BLOCKQUOTE>quote:<HR>Harefuah 2002 Mar;141(3):272-7, 314, 313

The placebo effect--a biochemical basis for a psychosomatic phenomenon

Article in Hebrew

Nitzan U, Hersco-Levy U, Lichtenberg P.

Haddasah Medical School, Jerusalem.

We review the research over the past decade on the subject of the Placebo Neurochemical mechanism, and it's random presence in the clinic. Our goal is to present the scientific basis of the placebo, and to arouse the awareness of physicians and scientists to the crucial role of placebo in medicine and pharmacological research. The modeling of rationality in modern times displaced the placebo issue to the sidelines of consensus, and it was only around 1950 that scientific interest in the phenomenon reawakened. Today the existence of a Placebo Effect is not doubted--not in everyone, and not at all times, but it's existence is not doubted in relation to groups of people throughout their lives. The involvement of a neurochemical mechanism in the Placebo Effect is also supported by the literature presented, and chemicals such as CCK, Naloxone, Proglumide, and Endorphins seem to effect the neuronal webs mediating the Analgestic Placebo Effect.<HR></BLOCKQUOTE>

And if you are thinking that you need to take drugs to affect these various neurotransmitter receptors, well you may be wrong. There's quite a bit of work going on now showing that there are real biochemical changes that go on with behavioral therapy that mimics the results achieved by pharmacologic therapy.

Fascinating stuff!

- Bill

Deep Sea · Post by **Deep Sea** » Thu Oct 03, 2002 2:39 am

I love it, Bill, absolutely.

I ran with the runner's high almost every day during my last 3-5 years of long-distance running, starting at about 7.5 miles into the run, so I know its effect very well.

During the last bunch of months at the Torture Chamber at Bethoney's dojo, I began experiencing the runner's high again doing kata, a-la TC. I think I now know how to turn it on, and it's a real turn-on.

So if one asks me why I continue to practice karate long after my fighting days have been extinguished, and I respond with "because it makes me feel good." They don't know how good it makes me feel [what a rush] -- nor what they are missing out on. I definitely can't say I don't inhale when running or doing kata.

------------------
Allen Moulton from Uechi-ryu Etcetera

jorvik · Post by **jorvik** » Thu Oct 03, 2002 3:32 pm

Just a thought, people seem to do pretty well against wild animals...the archer shooting the bear, there was a post a while back about a guy taking out a folding knife to kill a mountain lion that attacked him( not a fast opening knife, just a penknife)....now I don't know what the definition of Fine over gross motor skills is...but to me these seem pretty fine..........so the old built in survival system seems to work well, for what it was intended to do. The point that I'm making is that there was no confusion here both people knew that they were fighting for their lives against a wild animal that they could not reason with, and would not be held accountable for killing...so they acted with only one thought in mind. This would be different if they had to fight a person and their responce would change....could this be a possible key in understanding how we behave in stressful situations?

Also Bill. you've discussed the chemicals for fear....what about anger? are they the same. Can you change your fear to anger?.......sometimes I think that I can.
I'd also like to say how much I appreciate you and Ian taking the time to talk about these subjects......I'm always suspicious of non-medical folk offering their opinions on these type of things, I am frightened that they may miss something so fundamental, which a trained man never would. No offence intended to anyone present or not...............and just another thought,what happens to fine/gross motor skills if I get angry?
[This message has been edited by jorvik (edited October 03, 2002).]

[This message has been edited by jorvik (edited October 03, 2002).]