Anterolateral system (AS) neurons transmit pain signals from the spinal cord to the brain. Their morphology, anatomy and physiological properties have been extensively characterised and suggest that specific AS neurons and their brain targets are concerned with the discriminatory aspects of noxious stimuli, such as their location or intensity, and their motivational/emotive dimension. Among the recently unravelled molecular markers of AS neurons is the developmentally-expressed transcription factor Phox2a, affording us the opportunity to selectively disrupt the embryonic wiring of AS neurons to gain insights into the logic of their adult function. Since mice with a spinal cord-specific loss of the netrin-1 receptor DCC have increased AS neuron innervation of ipsilateral brain targets and defective noxious stimulus localisation or topognosis, we generated mice of either sex carrying a deletion of Dcc in Phox2a neurons. Such DccPhox2a mice displayed impaired topognosis along the rostrocaudal axis, but with l...