Dr. Fred Lenz has conducted more than 25 years of RO1 NIH-funded research and extensive experience as a scientific editor and reviewer. He has written over one hundred manuscripts on these subjects and trained many fellows from around the world.
Although functional imaging studies have demonstrated the presence of activations at several regions of the human brain in the classic pain network. Thirty years ago there was no direct evidence in humans of nociceptive input to these structures, or of functional connectivity between them. Dr. Lenz' lab has demonstrated thalamic structures involved in the processing of acute and chronic pain by the activity of single neurons to painful stimuli, and the effect of microstimulation and lesions of these structures. Similar involvement of cortical structures was demonstrated by the response to painful stimuli and lesions. The studies of functional and causal interactions within the classic pain network represented the first application of these techniques to the neuroscience of pain.
Ongoing work is using similar techniques to study the relationship of these activations and interactions to expectation and vigilance toward pain which are related to chronic pain syndromes. Finally, with Drs. Casey, Jones and Willis, Dr. Lenz has co-authored The Human Pain System (Cambridge, 2010) which is "...the most comprehensive and up-to-date review of the research literature on the anatomy and physiology of … the pain experience" (American Psychological Assoc Book Reviews).
Although there has long been evidence of plasticity of the CNS pain system in animals, there was limited direct evidence in patients with chronic pain, and with disorders of the somatic sensory and motor systems. Dr. Lenz's lab has demonstrated the presence of plasticity in the human thalamus and cortex during chronic pain secondary to major injuries to the nervous system including spinal cord transection, amputation and stroke, as well as in the basal ganglia and thalamus during movement disorders such as dystonia. These studies demonstrate the presence of plasticity in these disorders, and the applicability of results of animal studies to humans. The team has also conducted studies that show plasticity in the form of fear conditioning.
Thirty years ago the paucity of studies of human single neuron activity by techniques for signal analysis was a barrier to the understanding of movement disorders. Throughout his career, Dr. Lenz has applied single neuron and local field potential recording techniques as required during awake surgery on the thalamus and basal ganglion in patients with movement disorders. These recordings and simultaneous EMG recordings were analyzed by signal analysis techniques. The results have clarified the role of plasticity, feedback and central oscillators in these disorders. Dr. Lenz refined and reintroduced techniques for recording human single neuron activity in the 1980s. These techniques were applied in neurosurgery internationally by fellows and visitors to the Toronto General Hospital and Johns Hopkins Hospital. At Johns Hopkins, Dr. Lenz improved upon techniques for the fabrication of microelectrodes, and for perturbing the motor system with a torque motor (US Patent 6,589,190, July 8, 2003 Quantitative Assessment of Muscle Tone in the Wrist. Lead Inventor: B.J. deLateur).
Fear conditioning is associated with dynamic directed functional interactions between and within the human amygdala, hippocampus and frontal lobe. C.C.Liu, N.E.Crone, P.J. Franaszczuk, D. Cheng, D.S. Schretlen, F.A.Lenz, Neuroscience 189: 359-369, 2011. PMID: 21664438. PMCID: PMC3048957. DOI: 10.1016/j.neuroscience.2011.05.067. NIHMSID 307888., Publ.ID: NSC13004. Pub 8/12/2011.
Effect of N-arachidonoyl-l-serine on human cerebromicrovascular endothelium. Kino T, Tomori T, Abutarboush R, Castri P, Chen Y, Lenz FA, McCarron RM, Spatz M. Biochem Biophys Rep. 2016 Sep 21;8:254-260. doi: 10.1016/j.bbrep.2016.09.002. eCollection 2016 Dec. PMID: 28955964.
Oscillatory EEG Activity induced by Conditioning Stimuli during Fear Conditioning reflects Salience and Valence of these Stimuli more than Expectancy. JH Chien, A Korzeniewska, L Colloca, CM Campbell, FA Lenz.. Neurosci. 346:81-93, 2017, PMID: 28077278. NIHMS 841882. DOI:10.1016/j.neuroscience.2016.12.047. PII:S0306-4522(16)30747-3.
Human Thalamic Somatosensory Nucleus (Ventral Caudal, Vc) as a Locus for Stimulation by Inputs from Tactile, Noxious and Thermal Sensors on an Active Prosthesis. Chien JH, Korzeniewska A, Colloca L, Campbell C, Dougherty P, Lenz F. Sensors (Basel). 2017 May 24;17(6). pii: E1197. doi: 10.3390/s17061197.. PMID: 28538681
Multi-Regional Adaptation in Human Auditory Association Cortex. Malinowska U, Crone NE, Lenz FA, Cervenka M, Boatman-Reich D. Front Hum Neurosci. 2017 May 9;11:247. doi: 10.3389/fnhum.2017.00247. eCollection 2017.PMID: 28536516