Fig. 1.

In vivo recordings of [K⁺]_o. A, Simultaneous measurement of [K⁺]_o and single unit activity in response to visual stimulation with a moving bar in the anesthetized cat primary visual cortex. Arrows indicate directions of stimulus. 1 mV corresponds to approximately 0.17 mM (Kofuji and Newman 2004). Stimuli with orientations different from the preferred orientation elicited neither spiking nor increases in [K⁺]_o (not shown). Figure adapted with permission from Singer and Lux (1975) © Elsevier. B, Simultaneous [K⁺]_o and depth EEG recording during slow oscillation in ketamine-xylazine anesthetized cat in suprasylvian gyrus. Figure adapted with permission from Amzica and Steriade (2000) © Society for Neuroscience. C, Simultaneous [K⁺]_o and field recording during tonic-clonic seizure in response to electrical stimulation in cat pericruciate cortex. Figure adapted with permission from Sypert and Ward (1974) © Elsevier.