302 K. Mackie
Fig. 1.CB 1 expression in human brain. CB 1 receptors were detected by quantitative autoradiography using
tritiated CP55,940. Strikingly high levels are found in the substantia nigra pars reticulata (SNR) and the internal
segment of the globus pallidus (GPi). Moderate levels are present in the caudate, putamen, the external
segment of the globus pallidus (GPe), amygdala, and cortex. Lesser levels are present in hypothalamus, and
verylowexpressionisapparentinmostareasofthethalamus.ThelaminarnatureofCB 1 expressionisapparent
in the most rostral parts of the cortex.Scale bar= 1 cm. (Original figure provided by Miles Herkenham)