Dual labelling of neurons with CB-HRP/TRPM8 fluorescent immunohistochemistry in rats. A: CB-HRP positive neurons (red). The cell bodies of dCSF-CNs were in the brain parenchyma and the processes were extended into CSF. B: the same section showing TRPM8 positive neurons (green). C: same section showing CB-HRP/TRPM8 double-labeled neurons (arrow, yellow). All CB-HRP/TRPM8 double-labeled neurons were coincident with the neurons labeled by CB-HRP. Scale bar: 100 μm.