By Narda Robinson, DO, DVM

By Narda Robinson, DO, DVM

The reflexive reach for drugs to treat anxiety, depression and mental health disorder is worsening.¹ Writing a prescription for a psychotropic drug is quick and painless for the practitioner; health insurance reimbursements are higher and easier to obtain.²

Psychiatry for humans, overall, has become largely the practice of pharmaceutical psychopharmacology, many times without the degree of safe and positive outcomes that patients are seeking. Is this over-reliance on psychotropic drugs seeping into to veterinary practice?

Some say it is.

According to a 2008 report in the New York Times called "Pill-Popping Pets:"

"The practice of prescribing medications designed for humans to animals has grown substantially over the past decade and a half, and pharmaceutical companies have recently begun experimenting with a more direct strategy: marketing behavior-modification and 'lifestyle' drugs specifically for pets."³  

This "pop a pill to cure your ill" culture does little to address the medical, social or environmental problems causing emotional discomfort in an animal. It also turns our focus away from researching ways to improve psychological states naturally, relying more on methods that adjust the body's own neurochemistry instead of a brightly colored capsule.

While plant-based compounds also offer relief from anxiety and distress, we need much more research on herbs for animals to better understand their risks and benefits.

That said, there are similar chemicals as those found in cannabis, poppies and chamomile tea already within our own nervous system and those of nonhuman animals. These include, but are not limited to: endocannabinoids, endogenous opioids and now endogenous benzodiazepines.

We, like plants, create not only the neurotransmitters themselves but also receptors for them, often from genes similar to those used by the plant kingdom.⁴

How is it that animals and plant-based foods, such as chocolate, wine and tea, wound up expressing similar psychoactive chemicals? Is it the result of the co-evolution of plants and animals — a means of communication within and between animals, plants, fungi and bacteria?⁵

Or might plants have nervous systems that respond in some similar manner to neurotransmitters, such as gamma-aminobutyric acid (GABA), a significant inhibitory neurotransmitter in the animal brain?

GABA, for example, appears to function as a "conserved and ubiquitous biological signaling molecule" across plants and animals. The overlapping chemistry is now causing some plant neurobiologists to ask, do plants have brains?⁶

Regardless of the structure of a photosynthesizer's nervous system, how might one cultivate an improved neurotransmitter profile in our patients? Aside from taking in GABA-ergic and other mind-mollifying foodstuffs, is there a way we can modulate the nervous system with approaches such as acupuncture?

Indeed. The role of manipulating the endogenous opioid system with acupuncture has a long history of study and exploration.⁷ Introducing electrical stimulation through the needles further tailors the type of transmitter released, based on whether one selects a high, low or mixed frequency.⁸

More recently, researchers are looking toward the endocannabinoid (eCB) system, along with ways to upregulate the endogenous production of cannabinoids naturally, through interventions such as massage, manipulation, acupuncture and herbs^.9

The next endogenous neurotransmitters receiving interest are the endogenous benzodiazepines, or "endozepines," found in the blood and brain¹⁰. These natural, endogenous ligands for benzodiazepine receptors occur not only in human brains but also in other animals.

It remains unclear how the body itself might synthesize endozepines, but we know that microbes may produce them, as do certain foods such as potatoes, tomatoes and chamomile tea.^{11 12}

Does the body produce its own valium-like compounds? Could it be that physical medicine benefits the brain's endozepine balance as it does endorphins and endocannabinoids?

While science has, so far, only scratched the surface of endozepine pharmacology, it has revealed that endozepines work through two main mechanisms:

1. They potentiate the activity of the inhibitory neurotransmitter, gamma-aminobutyric acid, or GABA.
2. They activate specific binding sites on the GABAA receptor.¹³

While no evidence yet exists on how acupuncture might elevate endozepine levels, we can find abundant information on the influence of acupuncture on GABA receptors as well as GABA itself.

One study demonstrated, for example, that acupuncture improves locomotor function in rats with experimentally induced transient focal cerebral ischemia by enhancing the expression of GABA receptors.¹⁴ 

Another paper reported on the influence of acupuncture on several neurotransmitter systems, including opioids and GABA, on the autonomic neuromodulation of cardiovascular responses. More specifically, acupuncture affected the ability of GABA to regulate the cardiopulmonary bradycardia reflex at the level of the nucleus tractus solitarius in the brainstem.¹⁵

For addictive-drug dependence, acupuncture suppressed morphine self-administration by experimentally addicted rats by affecting the GABA receptor system.¹⁶ The list goes on.

Could acupuncture affect the body's release of its own homegrown, valium-type analogue?

Back in 1997, a panel of experts convened by the National Institutes of Health seems to have indicated that this could be the case. As one report indicated, "Some Western researchers say acupuncture triggers the production of many different chemicals, including pain-killing endorphins, calming endogenous benzodiazepines and mood-lifting serotonin."¹⁷ 

Now, almost 20 years later, there are still no reports that tighten this link between endozepines and acupuncture, other than ever more research highlighting its GABA-ergic effects.

But, what's causing those GABA responses to occur? Is there an endozepine somewhere in the mix?

The more we know about how to make the brain's own chemistry operate at a better level of function, whether through diet, exercise, music, massage or acupuncture, the less reliant we'll be on medications that don't really cure the problem, but instead may just be masking it.

References

1. Davey GCL. "Overprescribing drugs to treat mental health problems."  Psychology Today.  January 30, 2014.  Accessed at www.psychologytoday.com/blog/why-we-worry/201401/overprescribing-drugs-treat-mental-health-problems on 06-25-15.
2. Smith BL.  "Inappropriate prescribing."  American Psychological Association.  2012;43(6): 36.  Accessed at www.apa.org/monitor/2012/06/prescribing.aspx on 06-25-15.
3. Vlahos J.  "Pill-popping pets."  The New York Times Magazine.   July 13, 2008.  Accessed at www.nytimes.com/2008/07/13/magazine/13pets-t.html?em%22&_r=0 on 06-25-15.
4. DeSalle R and Tattersall I. "Do plants have brains?" Natural History Magazine.  Accessed on 06-25-15 at www.naturalhistorymag.com/features/152208/do-plants-have-brains .
5. Johnston GAR, Chebib M, Duke RK, et al. "Herbal products and GABA receptors."  Encyclopedia of Neuroscience.  2009;4:1095-1101.  Accessed on 06-25-15 at http://sydney.edu.au/medicine/pharmacology/adrien-albert/images/pdfs/RefsPDFs/390.pdf 
6. DeSalle R and Tattersall I.  "Do plants have brains?" Natural History Magazine.  Accessed on 06-25-15 at www.naturalhistorymag.com/features/152208/do-plants-have-brains .
7. Han JS. "Acupuncture and endorphins." Neurosci Lett. 2004;361(1-3):258-261.
8. Han J-S.  "Acupuncture:  neuropeptide release produced by electrical stimulation of different frequencies." TRENDS in Neuroscience.  2003;26(1):17-22.
9. McPartland JM, Guy GW and Di Marzo V. "Care and feeding of the endocannabinoid system:  a systematic review of potential clinical interventions that upregulate the endocannabinoid system."  PLoS ONE 9(3): e89566. doi:10.1371/journal.pone.0089566
10. Baraldi M, Avallone R, Corsi L, et al. "Natural endogenous ligands for benzodiazepine receptors in hepatic encephalopathy." Metab Brain Dis. 2009;24:81-93.  
11. Baraldi M, Avallone R, Corsi L, et al.  "Endogenous benzodiazepines."  Therapie.  2000;50:143-146.
12. Baraldi M, Avallone R, Corsi L, et al. "Natural endogenous ligands for benzodiazepine receptors in hepatic encephalopathy."  Metab Brain Dis. 2009;24:81-93.  
13. Baraldi M, Avallone R, Corsi L, et al. "Endogenous benzodiazepines." Therapie.  2000;50:143-146.
14. Xu Q, Yang JW, Cao Y, et al. "Acupuncture improves locomotor function by enhancing GABA receptor expression in transient focal cerebral ischemia rats."  Neuroscience Letters. 2015;588:88-94.
15. Tjen-A-Looi SC, Guo Z-L, and Longhurst JC. "GABA in nucleus tractus solitarius participates in electroacupuncture modulation of cardiopulmonary bradycardia reflex."  American Journal of Physiology - Regulatory, Integrative and Comparative Physiology.  2014;307(11):R1313-R1323.
16. Lee BH, Ku JY, Zhao RJ, et al.  "Acupuncture at HT 7 suppresses morphine self-administration at high dose through GABA system." Neuroscience Letters.  2014.  576:34-39.
17. Science News Staff.  NIH Panel commends acupuncture.  November 5, 1997.  Accessed at http://news.sciencemag.org/1997/11/nih-panel-commends-acupuncture on 06-25-15.

Originally published in the August 2015 issue of Veterinary Practice News.