A. Vania Apkarian
A. Vania Apkarian
Research in this laboratory is aimed at understanding pain perception and translating this understanding into better management of clinical pain states. Along this general goal we examine brain mechanisms of sensory information processing and the short-term and long-term re-organizational dynamics of the brain for different pain states. Our immediate research proceeds in two directions:
- Animal studies of neuronal population dynamics of touch perception, and somatic and visceral, acute and chronic pain perception. These studies entail multi-site multi-electrode recordings in behaving animals and relating these large-scale network properties to non-invasive brain imaging studies (functional magnetic resonance imaging and/or magnetic resonance spectroscopy performed in the same animals). The experiments are designed to enable the construction of computational models for the networks, which should help rigorously demonstrate the extent of our understanding of these networks.
- Human studies of experimental touch and somatic and visceral pain perception, and clinical acute and chronic pain conditions. These studies aim at studying brain activity patterns, brain chemistry changes, and relate the two to cognitive abilities.
The human and animal studies are closely coupled with each other to help understand the neuroscience underlying human clinical pain conditions. Our recent studies, e.g., show distinct populational coding properties for innocuous and noxious inputs to the thalamus, and show re-organization of this thalamic coding within minutes following a peripheral nerve damage that results in chronic pain like behavior in rats. Our recent human brain imaging studies show that we can differentiate between brain areas involved in coding painful stimuli from those involved in the subjective perception of pain. Moreover, our studies show that the brain network for chronic pain states is distinct from that for acute pain, that chronic pain may result in long-term regional brain degeneration that leads to specific cognitive deficits, and that the use of brain imaging techniques (functional and spectroscopic) can dramatically advance our understanding of clinical pain states. The long-term purpose of these studies is to bridge the gap between animal and human studies of sensory processing and to establish relationships across multiple scales of organization of the central nervous system to understand the dynamics of conscious perception of sensations.
Grachev ID, Apkarian AV. (2000) Chemical mapping of anxiety in the brain of healthy humans: an in vivo 1H-MRS study on the effects of sex, age, and brain region. Hum Brain Mapp. 11:261-272.
Apkarian AV, Shi T, Bruggemann J, Airapetian LR. (2000) Segregation of nociceptive and non-nociceptive networks in the squirrel monkey somatosensory thalamus.J. Neurophysiol. 84:484-494.
Apkarian AV, Gelnar PA, Krauss BR, Szeverenyi NM. (2000) Cortical responses to thermal pain depend on stimulus size: a functional MRI study.J. Neurophysiol. 83:3113-3122.
Apkarian AV, Darbar A, Krauss BR, Gelnar PA, Szeverenyi NM. (1999) Differentiating cortical areas related to pain perception from stimulus identification: temporal analysis of fMRI activity.J. Neurophysiol. 81:2956-2963.
Ivey C, Apkarian AV, Chialvo DR. (1998) Noise-induced tuning curve changes in mechanoreceptors.J. Neurophysiol. 79:1879-1890.