spinal cord dorsal/ventral patterning

Definition

Target type: biologicalprocess

The process that regulates the coordinated growth and differentiation that establishes the non-random dorsal-ventral spatial arrangement of the spinal cord. [GO_REF:0000021, GOC:cls, GOC:dgh, GOC:dph, GOC:jid]

Spinal cord dorsal/ventral patterning is a crucial developmental process that establishes the distinct identities of neurons and glial cells along the dorsal-ventral axis. This patterning is driven by a complex interplay of signaling molecules and transcription factors, orchestrated by a series of inductive events.

The process begins with the formation of the neural tube, a precursor to the central nervous system. The notochord, a rod-like structure along the dorsal midline, secretes Sonic hedgehog (Shh), a morphogen that diffuses ventrally. Shh acts as a concentration gradient, with the highest concentration at the ventral midline and progressively lower levels towards the dorsal side.

As Shh concentration varies, it triggers a cascade of gene expression events, defining distinct regions along the ventral axis. High Shh concentrations induce the expression of transcription factors like Nkx6.1 and Olig2, specifying motor neuron progenitors. Intermediate Shh levels activate transcription factors like Pax6 and Nkx2.2, defining interneuron progenitors.

Simultaneously, the dorsal side of the neural tube is patterned by signals emanating from the roof plate, a specialized structure dorsal to the neural tube. The roof plate secretes Bone morphogenetic proteins (BMPs), another family of morphogens, which act in a concentration gradient, highest at the dorsal midline and diminishing ventrally.

BMPs activate the expression of transcription factors like Msx1 and Pax6, specifying sensory neuron progenitors and dorsal interneuron progenitors, respectively.

The dorsal and ventral patterning processes converge, leading to the generation of a diverse array of neuronal subtypes, each with distinct functions. These subtypes are positioned along the dorsal-ventral axis according to their specific requirement for Shh and BMP signals.

Furthermore, other signaling pathways, such as Wnt, contribute to the fine-tuning of dorsal/ventral patterning. Wnt signals from the dorsal side influence the differentiation of specific subtypes of interneurons.

The intricate interplay of Shh, BMP, and Wnt signaling pathways, alongside the actions of numerous transcription factors, ensures the precise and ordered differentiation of neuronal and glial cell subtypes along the dorsal-ventral axis of the spinal cord, forming the basis for the proper functioning of the nervous system.'
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Proteins (3)

Compounds (19)