In the developing

nervous system In biology, the nervous system is the highly complex part of an animal that coordinates its actions and sensory information by transmitting signals to and from different parts of its body. The nervous system detects environmental changes ...

, the basal plate is the region of the

neural tube In the developing chordate (including vertebrates), the neural tube is the embryonic precursor to the central nervous system, which is made up of the brain and spinal cord. The neural groove gradually deepens as the neural fold become elevated, ...

ventral to the sulcus limitans. It extends from the rostral mesencephalon to the end of the

spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the sp ...

and contains primarily motor

neuron A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa ...

s, whereas neurons found in the

alar plate Daminozide—also known as aminozide, Alar, Kylar, SADH, B-995, B-nine, and DMASA,—is a plant growth regulator, a chemical sprayed on fruit to regulate growth, make harvest easier, and keep apples from falling off the trees before they ripen s ...

are primarily associated with sensory functions. The cell types of the basal plate include

lower motor neuron Lower motor neurons (LMNs) are motor neurons located in either the anterior grey column, anterior nerve roots (spinal lower motor neurons) or the cranial nerve nuclei of the brainstem and cranial nerves with motor function (cranial nerve low ...

s and four types of

interneuron Interneurons (also called internuncial neurons, relay neurons, association neurons, connector neurons, intermediate neurons or local circuit neurons) are neurons that connect two brain regions, i.e. not direct motor neurons or sensory neurons. ...

. Initially, the left and right sides of the basal plate are continuous, but during

neurulation Neurulation refers to the folding process in vertebrate embryos, which includes the transformation of the neural plate into the neural tube. The embryo at this stage is termed the neurula. The process begins when the notochord induces the form ...

they become separated by the

floor plate The floor plate is a structure integral to the developing nervous system of vertebrate organisms. Located on the ventral midline of the embryonic neural tube, the floor plate is a specialized glial structure that spans the anteroposterior axis f ...

, and this process is directed by the

notochord In anatomy, the notochord is a flexible rod which is similar in structure to the stiffer cartilage. If a species has a notochord at any stage of its life cycle (along with 4 other features), it is, by definition, a chordate. The notochord consi ...

. Differentiation of neurons in the basal plate is under the influence of the protein

Sonic hedgehog Sonic hedgehog protein (SHH) is encoded for by the ''SHH'' gene. The protein is named after the character ''Sonic the Hedgehog''. This signaling molecule is key in regulating embryonic morphogenesis in all animals. SHH controls organogenesis a ...

released by ventralizing structures, such as the notochord and floor plate. Gray642.png, The basal plate (basal lamina) is separated from the

(alar lamina) by the sulcus limitans (unlabeled).

References

;Bibliography *

External links

Overview at temple.edu
* {{Authority control Embryology of nervous system