Neurophysiological work in the Dafny/Swann Lab focuses on several areas. These include the following:

Pain Suppression Mechanisms

Since the discovery that profound analgesia can be produced by focal electrical stimulation of midbrain structures (e.g., periaqueductal gray, dorsal raphe), it has become increasingly apparent that analgesia is in part related to opioid agonists that interact with a variety of receptors and endogenous opioids. Pain modulation is a dynamic process which involves continuous interactions among complex ascending and descending pathways. Our pain research focuses on defining the sites responsible for the modulation of pain.

Mechanisms of Drug Abuse

In addition to behavioral studies on the effects of drugs of abuse, our laboratory uses electrophysiological techniques to uncover the mechanisms and modulators of Drug abuse. For example, we have shown that noninvasive, subthreshold auricular electrical stimulation (AES) may be used as a treatment to reduce the severity of precipitated and of abrupt opiate withdrawal, and explored the mechanism of irradiation-induced on changes in opiate withdrawal.

Neurophysiological Basis of Behavioral Sensitization

The work in this area focuses on uncovering the brain structures responsible for the development and expression of behavioral sensitization. Because repeated treatment with stimulants is believed to cause release of dopamine from areas like the prefrontal cortex, nucleus accumbens, ventral tegmental area, and caudate-putamen, recordings of neruonal activity from these areas are studied.
Our overall objective is to investigate behavioral and neurophysiological aspects of behavioral sensitization as the fundamental mechanisms underlying the effect of long-term sequelae of methylphenidate (Ritalin) administration, which is the drug of choice for the treatment of ADHD. The neurophysiological studies will investigate brain sites considered to be essential in the induction and expression of sensitization to psychostimulants. In addition we are making an effort to develop non-invasive electrophysiological procedures to differentiate between ADHD and non-ADHD subjects.