Distribution of CX
CL1 mRNA expressing cells in the normal rat brain. Coronal sections sampled at regular intervals throughout the rostro-caudal extent of the normal rat brain hybridized with a 35S-labeled antisense-CRNA probe encoding rat CX3CL1. Cells expressing mRNA encoding the chemokine are visualized as accumulations of white silver grain in this microscopic darkfield illumination at low magnification. The letters in each subfigure refer to the approximate levels according to the Paxinos stereotaxic brain atlas . The highest levels of CX3CL1 mRNA were detected exclusively within the grey matter of the cerebral cortex (A:a, B:a, C:a, D:a), hippocampus (C:b), septum (B:c), thalamus (C:d) and striatum (B:e). Medium to low level expression was detected in the hypothalamus (C:f), pons (E:g), mesencephalon (D:h), medulla oblongata (not shown) and spinal cord (F:i). The cerebellum (E:j) was devoid of CX3CL1 expression, except for a low level of expression in the deep cerebellar nuclei. Parallel sections hybridized with a sense-transcribed CX3CL1 cRNA probe of equal specific activity did not reveal signals above background levels.