Repetitive concentric wave-ring spread of oligemia/hyperemia in the sensorimotor cortex accompanying K +-induced spreading depression in rats and cats

• Published in: Neuroscience letters 2002-04, Vol.322 (3), p.157-160
• Main Authors: Tomita, Yutaka, Tomita, Minoru, Schiszler, Istvan, Amano, Takahiro, Tanahashi, Norio, Kobari, Masahiro, Takeda, Hidetaka, Ohtomo, Manabu, Fukuuchi, Yasuo
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Blood Volume - drug effects; Blood Volume - physiology; Cats; Cerebral blood volume; Cerebral circulation. Blood-brain barrier. Choroid plexus. Cerebrospinal fluid. Circumventricular organ. Meninges; Cerebrovascular Circulation - drug effects; Cerebrovascular Circulation - physiology; Cortical Spreading Depression - physiology; Fundamental and applied biological sciences. Psychology; Hyperemia; Hyperemia - chemically induced; Hyperemia - physiopathology; Light; Light transmission; Microinjections; Motor Cortex - blood supply; Motor Cortex - drug effects; Oligemia; Optical method; Potassium; Potassium - pharmacology; Rats; Rats, Sprague-Dawley; Somatosensory Cortex - blood supply; Somatosensory Cortex - drug effects; Species Specificity; Spreading depression; Vertebrates: nervous system and sense organs
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/S0304-3940(02)00072-1

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 α-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.