Figure 8. Proposed model for the thin afferent convergence on to an SG neurone.

Re-convergence model, three converging fibres originate from one cutaneous reference point, ascend in a common peripheral nerve and diverge at the level of segmental spinal nerves, in order to re-converge again on to an SG neurone. The Re-convergence model was developed to explain formation of precise and robust somatotopic maps and to comply with observations of Takahashi et al. (2003). Convergence model, in this alternative model three centrally converging afferents originate from different terminal branches of a common peripheral nerve. In the Convergence model, the peripheral divergence strongly increases the cutaneous area projecting to a single SG receptive field.