Characteristics of neurons with high-frequency discharge in the central nervous system and their relationship to chronic pain. Experimental and clinical investigations.
High-frequency extracellular unitary activity was recorded mainly in the ventral caudal nucleus of the thalamus in chronic-pain patients. These high-frequency discharge (hyperactive) neurons shows three types of discharge pattern with different interval histograms. Some of these hyperactive neurons were suppressed by the administration of a calcium antagonist (nicardipine). In an experimental study, chronic-pain models were made in rats according to the method of Lombard et al. (1979). From these animals, hyperactive neurons were recorded from the contralateral thalamic nuclei, lemniscus medialis. Hyperactive neurons were examined via electrical stimulation of and/or iontophoretic application. The results suggest that there is some relationship to the glutamatergic and GABAergic (probably GABAA) fibers or receptors.
Department of Neurosurgery, University of the Ryukyus School of Medicine, Okinawa, Japan.
K
K
Yamashiro
N
N
Tomiyama
A
A
Ishida
Y
Y
Terada
J
J
Mukawa
Y
Y
Yoshii
R R
RR
Tasker
D
D
Albe-Fessard
D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002908:Chronic Disease; D003714:Denervation; D004195:Disease Models, Animal; D004558:Electric Stimulation; D007839:Functional Laterality / Q000502:physiology; D018698:Glutamic Acid / Q000502:physiology*; D006801:Humans; D007478:Iontophoresis; D008839:Microelectrodes; D009431:Neural Conduction / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D009529:Nicardipine / Q000494:pharmacology; D010146:Pain / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000502:physiology; D013238:Stereotaxic Techniques; D013787:Thalamic Nuclei / Q000187:drug effects / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
D002121:Calcium Channel Blockers; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid; D009529:Nicardipine