S. M. Crain and K.-F. Shen, “Low Doses of Cyclic AMP-Phosphodiesterase Inhibitors Rapidly Evoke Opioid-Mediated Thermal Hyperalgesia in Naive Mice which Is Converted to Prominent Analgesia by Cotreatment with Ultra-Low-Dose Naltrexone,” Brain Research, Vol. 1231, 2008, pp. 16-24.
 H. O. J. Collier, N. J. Cuthbert and D. L. Francis, “Character and Meaning of Quasi-Morphine Withdrawal Phenomena Elicited by Methylxanthines,” Federation Proceedings, Vol. 40, No. 5, 1981, pp. 1513-1518.
 S. M. Crain, B. Crain, E. R. Peterson and E. J. Simon, “Selective Depression by Opioid Peptides of SensoryEvoked Dorsal-Horn Network Responses in Organized Spinal Cord Cultures,” Brain Research, Vol. 157, No. 1, 1978, pp. 196-201.
 K.-F. Shen and S. M Crain, “Dual Opioid Modulation of the Action Potential Duration of Mouse Dorsal Root Ganglion Neurons in Culture,” Brain Research, Vol. 491, No. 2, 1989, pp. 227-242.
 S. M. Crain and K.-F. Shen, “After Chronic Opioid Exposure Sensory Neurons Become Supersensitive to the Excitatory Effects of Opioid Agonists and Antagonists as Occurs after Acute Elevation of GM1 Ganglioside,” Brain Research, Vol. 575, No. 1, 1992, pp. 13-24.
 S. M. Crain and K.-F. Shen, “Modulation of Opioid Analgesia, Tolerance, and Dependence by Gs-Coupled, GM1 Ganglioside-Regulated Opioid Receptor Functions,” Trends in Pharmacologic Science, Vol. 19, No. 9, 1998, pp. 358-365. http://dx.doi.org/10.1016/S0165-6147(98)01241-3
 S. M. Crain and K.-F. Shen, “Ultra-Low Concentrations of Naloxone Selectively Antagonize Excitatory Effects of Morphine on Sensory Neurons, Thereby Increasing Its Antinociceptive Potency and Attenuating Tolerance/Dependence during Chronic Cotreatment, “Proceedings of the National Academy of Sciences of the United States of America, Vol. 92, No. 23, 1995, pp. 10540-10544.
 S. M. Crain and K.-F. Shen, “Acute Thermal Hyperalgesia Elicited by Low-Dose Morphine in Normal Mice Is Blocked by Ultra-Low-Dose Naltrexone, Unmasking Potent Opioid Analgesia,” Brain Research, Vol. 888, No. 1, 2001, pp. 75-82.
 S. M. Crain and K.-F. Shen, “Antagonists of Excitatory Opioid Receptor Functions Enhance Morphine’s Analgesic Potency and Attenuate Opioid Tolerance/Dependence Liability,” Pain, Vol. 84, No. 2-3, 2000, pp. 121-131.
 K. J. Powell, N. S. Abul-Husn, A. Jhamandas, M. C. Olmstead, R. J. Beninger and K. Jhamandas, “Paradoxical Effects of the Opioid Antagonist Naltrexone on Morphine Analgesia, Tolerance, and Reward in Rats,” Journal of Pharmacological and Experimental Therapeutics, Vol. 300, No. 2, 2002, pp. 588-596.
 N. S. Abul-Husn, M. Sutak, B. Milne and K. Jhamandas, “Augmentation of Spinal Morphine Analgesia and Inhibition of Tolerance by Low Doses of Muand Delta-Opioid Receptor Antagonists,” British Journal of Pharmacology, Vol. 151, No. 6, 2007, pp. 877-887.
 H.-Y. Wang, E. Friedman, M. C. Olmstead and L. H. Burns, “Ultra-Low-Dose Naloxone Suppresses Opioid Tolerance, Dependence and Associated Changes in Mu Opioid Receptor-G Protein Coupling and Gbetagamma Signaling,” Neuroscience, Vol. 135, No. 1, 2005, pp. 247-261.
 R. Y. Tsai, Y. H. Tai, I. Tzeng, C. H. Cherng, C. C. Yeh and C. S. Wong, “Ultra-Low-Dose Naltrexone Restores the Antinociceptive Effect of Morphine in Pertussis ToxinTreated Rats by Reversing the Coupling of Mu-Opioid Receptors from Gs-Protein to Coupling to Gi-Protein,” Neuroscience, Vol. 164, No, 2, 2009, pp. 435-443.
 L. R. Webster, P. G. Butera, L. V. Moran, N. Wu, L. H. Burns, and N. Friedman, “Oxytrex Minimizes Physical Dependence while Providing Effective Analgesia: A Randomized Controlled Trial in Low Back Pain,” Journal of Pain, Vol. 7, No. 12, 2006, pp. 937-946.
 K.-F. Shen and S. M. Crain, “Cholera Toxin-B Subunit Blocks Excitatory Effects of Opioids on Sensory Neuron Action Potentials Indicating that GM1 Ganglioside May Regulate Gs-Linked Opioid Receptor Functions,” Brain Research, Vol. 531, No. 1-2, 1990, pp. 1-7.
 K.-F. Shen and S. M. Crain, “Cholera Toxin-B Submit Blocks Excitatory Opioid Receptor-Mediated Hyperalgesic Effects in Mice, Thereby Unmasking Potent Opioid Analgesia and Attenuating Opioid Tolerance/Dependence,” Brain Research, Vol. 919, No. 1, 2001, pp. 20-30.
 G. Wu, Z.-H. Lu, and R. W. Ledeen, “Interaction of Delta-Opioid Receptor with GM1 Ganglioside: Conversion from Inhibitory to Excitatory Mode,” Brain Research. Molecular Brain Research, Vol. 44, No. 2, 1997, pp. 341-346. http://dx.doi.org/10.1016/S0169-328X(96)00281-1
 G. Wu, Z.-H. Lu, T. J. Wei, R. D. Howells, K. Christoffers and R. W. Ledeen, “The Role of GM1 in Regulating Excitatory Opioid Effects,” Annals of the New York Academy of Sciences, Vol. 845, 1998, pp. 126-138.
 S. M. Crain and K.-F. Shen, “GM1 Ganglioside-Induced Modulation of Opioid Receptor-Mediated Functions,” Annals of the New York Academy of Sciences, Vol. 845, 1998, pp. 106-125.
 S. M. Crain and K.-F. Shen, “Chronic Morphine-Treated Sensory Ganglion Neurons Remain Supersensitive to the Excitatory Effects of Naloxone for Months after Return to Normal Culture Medium: An in Vitro Model of ‘Protracted Opioid Dependence,’” Brain Research, Vol. 694, No. 1-2, 1995, pp. 103-110.
 G. Wu, Z. H. Lu, N. Kulkami and R. W. Ledeen, “Deficiency of Gangioside GM1 Correlates with Parkinson’s Disease in Mice and Humans,” Journal of Neuroscience Research, Vol. 90, No. 10, 2012, pp. 1997-2008.
 S. M. Crain and K.-F. Shen, “Neuraminidase Inhibitor, Oseltamivir Blocks GM1 Ganglioside-Regulated Excitatory Opioid Receptor-Mediated Hyperalgesia, Enhances Opioid Analgesia and Attenuates Tolerance in Mice,” Brain Research, Vol. 995, No. 2, 2004, pp. 260-266.
 A. Greffard, N. Trabeisi, H. Terzidis, J. Bigmon, J. Javrand and Y. Pilatte, “Inhibition of Acid Sialidase by Inorganic Sulfate,” Biochimica et Biophysica Acta, Vol. 1334, No. 2-3, 1997, pp. 140-148.
 H. Koenig, T. Wallner, P. Marhofar, H. Andel, K. Horauf, and M. Nikolaus, “Magnesisum Sulfate Reduces Intraand Postoperative Analgesic Requirements,” Anesthesia and Analgesia, Vol. 87, No. 1, 1998, pp. 206-210.
 S. Seneff, R. Davidson and L. Mascitelli, “Might Cholesterol Sulfate Deficiency Contribute to the Development of Autistic Spectrum Disorder?” Medical Hypotheses, Vol. 78, No. 2, 2012, pp. 213-217.
 R. E. Galinsky and G. Levy, “Effect of n-Acetylcysteine on the Pharmacokinetics of Acetaminophen in Rats,” Life Sciences, Vol. 25, No. 8, 1979, pp. 693-699.
 M. M. Teixeira, R. W. Gristwood, N. Cooper and P. G. Hellewell, “Phosphodiesterase (PDE)4 Inhibitors: AntiInflammatory Drugs of the Future?” Trends in Pharmacological Science, Vol. 18, No. 5, 1997, pp. 164-171.
 K.-F. Shen and S. M. Crain, “Ultra-Low-Doses of Naltrexone or Etorphine Increase Morphine’s Antinociceptive Potency and Attenuate Tolerance/Dependence in Mice,” Brain Research, Vol. 757, No. 2, 1997, pp. 176-190. http://dx.doi.org/10.1016/S0006-8993(97)00197-2
 K.-F. Shen and S. M. Crain, “Cholera Toxin-B Subunit Blocks Excitatory Opioid Receptor-Mediated Hyperalgesic Effects in Mice, Thereby Unmasking Potent Opioid Analgesia and Attenuating Opioid Tolerance/Dependence,” Brain Research, Vol. 919, No. 1, 2001, pp. 20-30.
 M. C. Fournie-Zaluski, P. Challet, R. Bouboutou, A. Coulaud, P. Cherot, G. Waksman, J. Costentin and B. P. Roques, “Analgesic Effects of Kelatorphan, a New Highly Potent Inhibitor of Multiple Enkelphalin Degrading Enzymes,” European Journal of Pharmacology, Vol. 102, No. 3-4, 1984, pp. 525-528.
 M. A. Scheideler and G. Dawson, “Direct Demonstration of the Activation of UPD-N-Acetylgalactosamine: [GM3] N-Acetylgalactosaminyltransferase by Cyclic AMP,” Journal of Neurochemistry, Vol. 4, No. 5, 1986, pp. 1639-1643.
 S. Chakrabarti, N. J. Liu, J. E. Zadina, T. Sharma and A. R. Gintzler, “Pleiotropic Opioid Regulation of Spinal Endomorphin 2 Release and Its Adaptations to Opioid Withdrawal Are Sexually Dimorphic,” Journal of Pharmacology and Experimental Therapeutics, Vol. 340, No. 1, 2012, pp. 56-63.
 S. Crain, M. A. Crain and S. M Crain, “Emotional and Physical Distress Relief Using a Novel Endorphinergic Formulation,” Journal of Behavioral and Brain Science, Vol. 3, No. 6, 2013, pp. 441-453.
 S. F. La Vincente, J. M. White, A. A. Somogyi, F. Bochner and C. B. Chapleo, “Enhanced Buprenorphine Analgesia with the Addition of Ultra-Low-Dose Naloxone in Healthy Subjects,” Clinical Pharmacology & Therapeutics, Vol. 83, No. 1, 2007, pp. 144-152.
 C. S. Yuan, T. Karrison, J. A. Wu, T. K. Lowell, J. P. Lynch and J. F. Foss, “Dose-Related Effects of Oral Acetaminophen on Cold-Induced Pain: A Double-Blind, Randomized Placebo-Controlled Trial,” Clinical Pharmacology and Therapeutics, Vol. 63, No. 3, 1998, pp. 379-383.
 M. F. Rossato, N. A. Velloso, A. P, de Oliveira Ferreira, C. F. de Mello and J. Ferreira, “Spinal Levels of NonProtein Thiols Are Related to Nociception in Mice,” Journal of Pain, Vol. 11, No. 6, 2010, pp. 545-554.
 F. W. Bach and T. L Yaksh, “Release of Beta-Endorphin Immunoreactivity into Ventriculo-Cisternal Perfusate by Lumbar Intrathecal Capsaicin in the Rat,” Brain Research, Vol. 701, No. 1-2, 1995, pp. 192-200.
 G. J. McKenna, “Methadone and Opiate Drugs: Psychotropic Effect and Self-Medication,” Annals of the New York Academy of Sciences, Vol. 398, 1982, pp. 44-55.
 J. D. Lane, C. F. Pieper, B. G. Phillips-Bute, J. E. Bryant and C. M. Kuhn, “Caffeine Affects Cardiovascular and Neuroendocrine Activation at Work and Home,” Psychosomatic Medicine, Vol. 64, No. 4, 2002, pp. 595-603.
 F. R. Huebner, K. W. Lieberman, R. P. Rubino and J. S. Wall, “Demonstration of High Opioid-Like Activity in Isolated Peptides from Wheat Gluten Hydrolysates,” Peptides, Vol. 5, No. 6, 1984, pp. 1139-1147.
 C. Colantuani, P. Rada, J. McCarthy, C. Patten, N. Avena, A. Chadeayne and B. Hoebel, “Evidence that Intermittent, Excessive Sugar Intake Causes Endogenous Opioid Dependence,” Obesity Research, Vol. 10, No. 6, 2002, pp. 478-488. http://dx.doi.org/10.1038/oby.2002.66
 N. M. Avena, P. Rada and B. G. Hoebel, “Evidence for Sugar Addiction: Behavioral and Neurochemical Effects of Intermittent, Excessive Sugar Intake,” Neuroscience and Biobehavioral Reviews, Vol. 32, No. 1, 2008, pp. 20-39. http://dx.doi.org/10.1016/j.neubiorev.2007.04.019
 S. M. Crain and K.-F. Shen, “Naloxone Rapidly Evokes Endogenous Kappa Opioid Receptor-Mediated Hyperalgesia in Naive Mice Pretreated Briefly with GM1 Ganglioside or in Chronic Morphine-Dependent Mice,” Brain Research, Vol. 1167, No. 31-41, 2007, pp. 31-41.