Fig. 2.

Chronic cocaine decreased CBFv across the cerebrovascular tree. Quantitative CBFv (ODT) images in the somatosensory cortex of the (a, c) saline-treated control groups versus (b, d) those of the chronic cocaine-treated groups for 2 and 4 weeks. Image sizes are $3.2\times 3.2{\mathrm{mm}}^2$, $\text{scale bar}=200\mu \mathrm{m}$. Yellow, green, and blue arrows are used to demonstrate the large ($\overline{\mathrm{\phi }}=293.40\pm 52.25\mu \mathrm{m}$; ${\mathrm{\phi }}_{\mathrm{L}}\ge 200\mu \mathrm{m}$), medium ($\overline{\mathrm{\phi }}=124.27\pm 16.09\mu \mathrm{m}$; $100\mu \mathrm{m}\le {\mathrm{\phi }}_{\mathrm{M}}<200\mu \mathrm{m}$), and small vessels ($\overline{\mathrm{\phi }}=56.23\pm 13.85\mu \mathrm{m}$; ${\mathrm{\phi }}_{\mathrm{S}}<100\mu \mathrm{m}$), respectively. (e, f) Statistical comparisons of CBFv among various groups, indicating the significant decreases of CBFv across the whole vascular trees. * significant differences between saline- and cocaine-treated groups ($n=5$, $m=12$; $*p<0.05$).