Mechanisms Of Pain, Pain Suppression, Stress And Drugs Of Abuse

The main focus of this laboratory is on two topics: pain mechanisms, including pain suppression and electro-acupuncture, and drug abuse mechanisms, involving morphine, cocaine, amphetamines, ritalin and ecstasy. Behavioral, neurophysiological, pharmacological, endocrinological, and immunological procedures are used, primarily with the rodent as an animal model. The electrophysiological procedures used include single cell and evoked potential recording, electroencephalography (EEG), and brain stimulation. Computerized techniques are used for monitoring animal behavior.

The laboratory is also involved with several other studies. These concern connections between the nervous, immune, and endocrine systems; brain regulation of hormonal secretion; mechanisms of obesity and satiety; and the electrophysiology of neurotransmitters such as dopamine, serotonin, and norepinephrine, and of peptides, with clinical application to Parkinsonism, Huntington’s chorea, and Tardive dyskinesia. In addition, we conduct collaborative immunological and endocrinologic studies with other groups in the Texas Medical Center.

Areas of Interest

Research Interests


Responses of a single neuron to pain stimuli alone and concomitant with morphine, naloxone, serotonin and methysergide.


Visit the PubMed profile page

  • Dafny, N. and Yang, P.B.  Interferon and the central nervous system.  Eur. J. Pharmacol., 523: 1-15, 2005.
  • Zhang, Y., Qiao, J.T. and Dafny, N.  C-fos antisense oligodeoxynucleotide effects behavioral nociceptive responses and both up-regulations of c-fos protein and dynorphin A (1-8) in dorsal horn: A study using the formalin test in rats.    Int. J. Neurosci., 115:935-948, 2005.
  • Prieto-Gomez, B., Vazquez-Alvarez, A.M., Martinez-Peña, J.L., Reyes-Vazquez, C., Yang, P.B. and Dafny, N.  Methylphenidate and amphetamine modulate differently the MNDA and AMPH glutamatergic transmission of dopaminergic neurons in the ventral tegmental area.  Life Sci., 77:635-649, 2005.
  • Yang, P.B., Swann, A.C. and Dafny, N.  Sensory evoked potentials recording from the ventral tegmental area, nucleus accumbens, prefrontal cortex and caudate and locomotor activity are modulated in dose response characteristics by methylphenidate.  Brain Res. 1073:164-174, 2006.
  • Yang, P.B., Swann, A.C. and Dafny, N. Chronic methylphenidate modulates locomotor activity and sensory evoked responses in the VTA and NAc of freely behaving rats.  Neuropharmacol., 51:546-556, 2006.
  • Yang, P.B., Swann, A.C. and Dafny, N.  Chronic administration of methylphenidate produces neurophysiological and behavioral sensitization.  Brain Res., 1145:66-80, 2007.
  • Lee, M.J., Yang, P.B., Wilcox, V.T., Burau, K.D., Swann, A.c., and Dafny, N. Does repetitive Ritalin injection produce long-term effects on SD female adolescent rats?  Neuropharmacol., 57: 201-207, 2009.
  • Podet A, Lee MJ, Swann AC, Dafny N. Nucleus accumbens lesions modulate the effects of methylphenidate. Brain Res Bull. Jul 30;82(5-6):293-301, 2010.
  • Chelaru MI, Yang PB, Dafny N. Sex differences in the behavioral response to methylphenidate in three adolescent rat strains (WKY, SHR, SD). Behav Brain Res., Aug 25;226(1):8-17, 2011.
  • Yang PB, Atkins KD, Dafny N. Behavioral sensitization and cross-sensitization between methylphenidate amphetamine, and 3,4-methylenedioxymethamphetamine (MDMA) in female SD rats. Eur J Pharmacol., Jul 1;661(1-3):72-85, 2011.
  • Yang PB, Cuellar DO 3rd, Swann AC, Dafny N. Age and genetic strain differences in response to chronic methylphenidate administration. Behav Brain Res., Mar 17;218(1):206-17, 2011.
  • Lee MJ, Yang PB, Wilcox VT, Burau KD, Swann AC, Dafny N. Repetitive methylphenidate administration modulates the diurnal behavioral activity pattern of adult female SD rats. J Neural Transm., Feb;118(2):285-98, 2011.

Curriculum Vitae

N. Dafny CV – January 2023