 |
Neuroscience Graduate Program at UCSF
Pain and Neural Plasticity in the Neural Circuitry of the Spinal Cord and Thalamus
Our laboratory studies the neural networks that serve somatic sensation, particularly pain, using model systems in rats and in macaque monkeys. Our current investigations are divided into two broad areas:
1) the reorganization of the spinal cord following experimentally-induced peripheral mononeuropathy; and,
2) neuronal plasticity in the somatosensory thalamus following central deafferentation lesions that are similar to those found in humans following injuries of the nervous system.
Particular elements of the neuronal networks are studied by electrophysiological techniques and subsequently analyzed with a variety of light and electron microscopic methods, as well as scanning confocal microscopy. Experimental methods used to analyze neural circuitry include the axonal transport of macromolecules, immunocytochemistry and the intracellular labeling of physiologically-characterized neurons. Changes in the expression of the receptor subtypes associated with excitatory and inhibitory neurotransmitters are evaluated using in situ hybridization techniques. Many of the findings concerning neuronal circuitry are further analyzed using computerized 3-dimensional reconstruction methods. The experimental manipulations are carried out in anesthetized animals using sterile neurosurgical techniques. Students and fellows in the laboratory are engaged in various aspects of these studies, and utilize several of the experimental methods described above to pursue their investigations. We also have an active collaborative study with neuroscientists in the department of Neurosurgery at the Johns Hopkins Medical School, which enables us to compare our findings of plastic changes in macaques with similar findings in humans.
Neural plasticity in animal models of chronic neuropathic pain.
1. Changes in the circuitry of the dorsal horn of the spinal cord in rats with peripheral nerve injury.
2. Plasticity of the inhibitory circuitry in the primate somatosensory thalamus following chronic spinal cord injury. (done in collaboration with investigators in the department of Neurosurgery at the Johns Hopkins School of Medicine, and the Department of Neuroscience, University of Florida).
Link to Publications via PubMed
Ralston, D.D. Present models of neuropathic pain. Pain Reviews 5: 83-100, 1998.
Ralston, D.D., P.M. Dougherty, F.A. Lenz, H.-R. Weng, C.J. Vierck and H.J. Ralston Plasticity of the inhibitory circuitry and neuronal responses in the primate somatosensory thalamus (VB) following lesions of the dorsal column and spinothalamic pathways. Proceedings of the 9th World Congress on Pain, M. Devor, M. Rowbotham and Z. Wiesenfeld-Hallin, Eds. in, Progress in Pain Research and Management. IASP Press, Seattle. 17: , 427-434, 2000.
VanderHorst, V. G. J. M., E. Terasawa, H. J. Ralston III. 2001 Monosynaptic projections from the nucleus retroambiguus region to laryngeal motoneurons in the rhesus monkey. Neuroscience. 107: 117-125.
VanderHorst, V. G. J. M., E. Terasawa, H. J. Ralston III. 2002 Estrogen receptor-alpha immunoreactive neurons in the ventrolateral periaqueductal gray receive monosynaptic input from the lumbosacral cord in the rhesus monkey. J. Comp. Neurol.443: 27-42.
VanderHorst, V.G.J.M., E. Terasawa, and H.J.III Ralston (2002) Axonal sprouting of a brainstem-spinal pathway after estrogen administration in the adult female rhesus monkey. J.Comp.Neurol. 454:82-103.
Ralston, H.J.III (2003) Pain, the brain, and the (calbindin) stain. J.Comp.Neurol. 459:329-333.
VanderHorst, V.G., E. Terasawa, and H.J Ralston III (2004) Projections from estrogen receptor-alpha immunoreactive neurons in the periaqueductal gray to the lateral medulla oblongata in the rhesus monkey. Neuroscience. 125: 243-253.
Henry J. (Peter) Ralston III, M.D.
Phone
415-476-1861
Physical Address
513 Parnassus
S-1334
Mailing Address
UCSF
Department of Anatomy
513 Parnassus, S-1334
San Francisco, CA 94143-0452
For Internal Campus Mail
Box 0452
Other Websites