Figure 5.

Proposed disynaptic circuit linking myelinated low-threshold primary afferents and lamina I projection neurons. The present results, together with findings from previous studies, suggest that vertical cells in lamina II receive monosynaptic input from a variety of types of primary afferent, including Aδ nociceptors (noci), both peptidergic and non-peptidergic (Mrgd-expressing) C fibres, as well as Aδ and/or Aβ low threshold mechanoreceptors (LTMR). Their postsynaptic targets include projection neurons in lamina I. For convenience, dendritic spines, which are likely to be major sites of excitatory synapses on vertical cells, have been omitted.