Repetitive concentric wave-ring spread of oligemia/hyperemia in the sensorimotor cortex accompanying K(+)-induced spreading depression in rats and cats.
Vascular changes accompanying spreading depression (SD) remain controversial. We examined dynamic alterations of local cerebral blood volume (CBV) during SD by observing light transmission at an isosbestic point of hemoglobin (550 nm) in seven rats and five cats under alpha-chloralose/urethane anesthesia. The two species were used for comparison between the lissencephalic and gyrencephalic brains. We found that a concentrated K(+) solution microinjected into the sensorimotor cortex provoked CBV changes that appeared as a repetitive propagation of concentric wave-rings of ischemia followed by hyperemia expanding peripherally from the injection site at speeds of 1.9-3.2 mm/min. The dynamic CBV changes continued repeatedly every 1-5 min for more than 30 min in three rats, ceased within 30 min in three rats and remained at the site of K(+) injection in one rat. Similar repeated CBV changes occurred in two out of five cats.
Tomita
Yutaka
Y
Department of Neurology, Saitama Municipal Hospital, 2460 Mimuro, Saitama City, Saitama 336-8522, Japan. y-tomita@med.keio.ac.jp
Tomita
Minoru
M
Schiszler
Istvan
I
Amano
Takahiro
T
Tanahashi
Norio
N
Kobari
Masahiro
M
Takeda
Hidetaka
H
Ohtomo
Manabu
M
Fukuuchi
Yasuo
Y
D000818:Animals; D001810:Blood Volume / Q000187:drug effects / Q000502:physiology*; D002415:Cats; D002560:Cerebrovascular Circulation / Q000187:drug effects / Q000502:physiology*; D013181:Cortical Spreading Depression / Q000502:physiology*; D006940:Hyperemia / Q000139:chemically induced / Q000503:physiopathology*; D008027:Light; D008845:Microinjections; D009044:Motor Cortex / Q000098:blood supply* / Q000187:drug effects; D011188:Potassium / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013003:Somatosensory Cortex / Q000098:blood supply* / Q000187:drug effects; D013045:Species Specificity
D011188:Potassium