Fig. 1.

Spatio-temporal changes in rCBF evoked by focal electrical stimulation of the left NBM in an anesthetized mouse obtained by laser speckle flowmetry. Electrical stimulation of the basal forebrain (0.9 mm posterior to the bregma, 2 mm lateral to the midline, 4 mm vertical under the bregma height, as indicated in (b) was carried out at 50 μA, 0.5 ms, 50 Hz, for 10 s. a Normal photo image (left) and diagram (right) of the viewing field, which is the entire dorsal surface of the brain with the olfactory bulb to the left side of each image and the occipital cortex to the right side of each image. b Specimen slice of a coronal section of brain on the left side 0.9 mm posterior to the bregma showing the position of the tip of the stimulating electrode (arrow). Scale bars in (a, b) represent 2 mm. c Averaged flow images over selected periods of 5 s, as indicated above each image (stimulus onset was set as time 0). d Differential signal change subtracting the baseline control signal (−5 to 0 s) from subsequent images. rCBF trace in the frontal (e, h), parietal (f, j) and occipital (g, k) cortices contralateral (e–g) and ipsilateral (h, j, k) to the site of stimulation, extracted from the ROIs indicated by the gray circles in (a). m Mean arterial pressure (MAP) simultaneously recorded