Bateson, P. 1992. Do animals feel pain? New Scientist April 25:30–33.

Breazile, J.E. 1987. Physiological basis and consequences of distress in animals. JAVMA 191(10): 1212–1215.

Carruthers, M. 1975. Biological responses to stress in the environment. Proceedings of the Royal Society of Medicine. 68:427–429.

Cassell J. 1970. Physical illness in response to stress. In: Social Stress, pp. 189–209, eds. S. Levine and N. Scotch. Idie: Chicago.

Chapman, C. Richard and Gavrin, Jonathan. 1999. Suffering: the contributions of persistent pain. The Lancet 353: 2233–2237.

Chudler, E.H. and Dong, W.K. 1995. The role of the basal ganglia in nociception and pain. Pain 60:3–38.

Dennis, S.G. and Melzack, R. 1983. Perspectives on phylogenetic evolution of pain expression. In: Animal pain: perception and alleviation, pp.151–160, ed. R.L. Kitchell, H.H. Erickson, E. Carstens, and L.E. Davis. Bethesda, MD: American Physiological Society.

Dubner, R., Basbaum, A.I. 1994. Spinal dorsal horn plasticity following tissue or nerve injury. In: Wall, P.D., Nelzak, R. (Eds.), Textbook of Pain. Churchill Livingstone, New York, pp. 230–233.

Eismann, C.H., Jorgenson, W.K., Merritt, D.J., Rice, M.J., Cribb, B.W., Webb, P.D., and Zalucki, M.P. 1984. Do insects feel pain?—A biological review. Experientia 40:164–167.

Fiorito, C. 1986. Is there pain in invertebrates? Behavioral Processes 12:383–388.

Freeman, B.M. 1975. Physiological basis of stress. Proceedings of the Royal Society of Medicine. 60:427–429.

Gracely, R.H., McGrath, P., and Dubner, R. 1978. Ratio scales of sensory and affective verbal pain descriptors. Pain 5:5–18.

Gray, J.A. 1982. The Neuropsychology of Anxiety. Oxford: Oxford University Press.

Guyton, A.C. 1991. Basic Neuroscience. Saunders, Philadelphia, PA.

Hardy, J. D., Wolff, H.G., and Goodell, H. 1952. Pain Sensation and Reaction. Baltimore: Williams & Wilkins.

Hargreaves, K. M. and Dubner, R. 1991. Mechanisms of pain and analgesia. In: Management of Pain and Anxiety in Dental Practice, R. Dionne and J. Phero, eds. New York: Elsevier. In press.

Herbert, J. 1989. Neuroendocrine responses to stress. Bailliere's Clinical Endocrinology and Metabolism 1.2: 467–490.

Hopkin, K. 1997. Show me where it hurts: tracing the pathways of pain. Journal of NIH Research 9:37–43.

Isaac, W. 1979. Causes and consequences of stress in the rat and mouse. Paper delivered at Stress Seminar, AALAS, Atlanta, GA.

Melzack, R and Wall, P.D. 1995. Pain mechanisms: A new theory. Science 150:971–979.

Moberg, G.P. and Mench, J.A., eds. 2000. The biology of animal stress: basic principles and implications for animal welfare. CABI Publishing. New York, New York.

Mogil, J.S., Richards, S.P, O'Toole, L.A., Helms, M.L., Mitchell, S, R., and Belknap, J. K. (1997). Genetic sensitivity to hot-plate nocioception in DBA/2J and C57BL/6J inbred mouse strains: possible sex-specific mediation by opioid receptors. Pain 70:267–277.

Mogil, J.S., Richards, S.P, O'Toole, L.A., Helms, M.L., Mitchell, S, R., West, B., and Belknap, J. K (1997). Identification of a Sex-Specific Quantitative Trait Locus Mediating Nonopioid Stress-Induced Analgesia in Female Mice. J. Neuroscience 17(20):7995–8002. www.jneurosci.org/cgi/reprint/17/20/7995

Narsinghani, U. and Anand, J.S. (2000) Developmental neurobiology of pain in neonatal rats. Lab Animal 29(9):27–39.

Perl, E.R. 1971. Is pain a specific sensation? Journal of Psychiatric Research 8:273–287.

Rose, M. and Adams, D. 1989. Evidence for pain and suffering in other animals. In: Animal Experimentation—The Consensus Changes, pp. 42–71, ed. G. Langley. London: Macmillan.

Sherwin, C. 2001. Can invertebrates suffer? Or, how robust is argument by analogy? Animal Welfare 10: S103–118.

Short, C.E. 1998. Fundamentals of pain perception in animals. Applied Animal Behaviour Science 59: 125–133.

Soulsby, L. and Morton D. (eds) 2001. Pain: its nature and management in man and animals. Royal Society of Medicine Press: London, United Kingdom.

Wigglesworth, V.B. 1980. Do insects feel pain? Antenna 4:8–9.

Willis, W.D. 1985. The Pain System—The Neural Basis of Nociceptive Transmission in the Mammalian Nervous System. New York: S. Karger.

Willis, W.D. and Chung, J.M. 1987. Central mechanisms of pain. JAVMA 191(10):1200–1202.

Yaksh, T. L. 1993. The central pharmacology of pain states. Proceedings (refresher Course Syllabus) of the 7th World Congress on Pain. Paris, France, August, pp. 13–30.