Fos expression in tyrosine hydroxylase-containing neurons in rat brainstem after visceral noxious stimulation: an immunohistochemical study

Figure 1 Drawing of the brainstem areas showing the distribution of TH, Fos and TH/Fos immunoreactive neurons after visceral noxious stimulation. Each■represents three TH-ir neurons. Each○represents five Fos-ir neurons. Each▲represents one TH/Fos double-labeled neuron. Abbreviations: 12: hypoglossal nuclei; 7n: facial nerve or its root; icp: inferior cerebellar peduncle; PAG: the midbrain periaqueductal gray; Pn: pontine nuclei; py: pyramidal tract; pyx: pyramidal decussation; scp: superior cerebellar peduncle; sol: solitary trace; SOL: solitary trace nuclei; sp5: spinal trigeminal tract; Sp5: spinal trigeminal nuclei.