Unique profile of spreading depression in a primate model.
Spreading depression (SD) is considered to play a role in pathologic conditions of humans such as in the evolution of ischemic brain injury and migraine aura. Because many studies have demonstrated spreading hypoperfusion in patients with migraine and persistent hypoperfusion in nonprimate animal models of SD, these changes in cerebral blood flow (CBF) were regarded as an epiphenomenon of SD. However, there is no direct evidence of the occurrence of SD in primates. The authors attempted to elicit SD by applying 3.3 mol/L potassium chloride to the cerebral cortex of nine male cynomolgus monkeys. The CBF was monitored by positron emission tomography in five animals. Propagated direct-current shifts were found by the two neighboring microelectrodes only in one animal. The direct-current wave propagated at a speed of 4 mm/min and its amplitude was 20 mV, being consistent with the SD findings. Except in one animal with 6 SD episodes, SD waves were recorded infrequently at the rostral site (none in three animals, once in three, and twice in two). Focal hyperemia accompanied SD. Neither spreading hypoperfusion nor persistent hypoperfusion was found. These unique features of SD in primates raise a doubt as to whether the role of SD in nonprimate animals is the same as that in stroke and migraine in humans.
Yokota
Chiaki
C
Department of Pathogenesis, Research Institute, Osaka, Japan. cyokota@ri.ncvc.go.jp
Kuge
Yuji
Y
Hasegawa
Yasuhiro
Y
Tagaya
Masafumi
M
Abumiya
Takeo
T
Ejima
Norimasa
N
Tamaki
Nagara
N
Yamaguchi
Takenori
T
Minematsu
Kazuo
K
D000818:Animals; D002540:Cerebral Cortex / Q000187:drug effects / Q000502:physiology; D013181:Cortical Spreading Depression; D004594:Electrophysiology; D008252:Macaca fascicularis / Q000502:physiology*; D008297:Male; D008839:Microelectrodes; D023421:Models, Animal; D011189:Potassium Chloride / Q000494:pharmacology; D014055:Tomography, Emission-Computed
D011189:Potassium Chloride