Key Difference – Neurulation vs Gastrulation
The key difference between Neurulation and Gastrulation is based on the type of development that takes place during embryogenesis. Neurulation results in the development of the nervous system whereas Gastrulation determines the process of developing the three germ layers.
Neurulation is the initial step of the development of the nervous system, where it gives rise to the neural plate that develops into a neural tube, finally giving rise to the spinal cord and the brain. Gastrulation is the process of development of the three germ layers; ectoderm, endoderm, and mesoderm.
CONTENTS
1. Overview and Key Difference
2. What is Neurulation
3. What is Gastrulation
4. Similarities Between Neurulation and Gastrulation
5. Side by Side Comparison – Neurulation vs Gastrulation in Tabular Form
6. Summary
What is Neurulation?
Neurulation is one stage of embryogenesis, where the vertebrate embryo folds and transforms its neural plate into a neural tube. Neurulation takes place in the endometrium between the 14th to the 17th day from fertilization. This process is the first step to the formation of the central nervous system that includes the brain and the spinal cord. The ectoderm of the embryo signals the formation of the neural tube. Upon evolution, the neural tube differentiated into more mature structures; brain and spinal cord.
Neurulation can be categorized as primary neurulation and secondary neurulation. During primary neurulation, the neural plate forms a crease inward until the edges get into close contact and fuse. This folding forms neural grooves and neural folds. The development of the notochord helps in the primary neurulation process. During secondary neurulation, the formation of the tube takes place by hollowing out itself out of a solid precursor.
Figure 01: Neurulation
Upon the completion of the secondary neurulation, the anterior portion of the neural tube is divided into three parts called forebrain, midbrain and the hindbrain, forming the complete brain structure. The neural tube also gives rise to the spinal cord.
What is Gastrulation?
Gastrulation is the process in which the three germ layers are differentiated in the embryo. The three germ layers are ectoderm, endoderm, and mesoderm. Takes place in the endometrium between the 7th to the 14th day from fertilization. During gastrulation, the blastula is formed into a multilayered structure. This structure is termed as the Gastrula. During gastrulation, the cell lineages are differentiated and the basic axes of the body are formed. The prospective gut develops following gastrulation.
Figure 02: Gastrulation
Based on the evolutionary patterns, different organisms show varied development of cell layers. If the organisms are triploblastic (mammals), they show all three layers in their development. If the organisms are diploblastic (cnidarians), they show only two cell layers; the ectoderm and the endoderm. There are some common characteristics observed in the development of the germ layers. They are topological structural changes, differentiation of ectodermal, endodermal and mesodermal cells, the formation of the gut and the digestive function.
What are the Similarities Between Neurulation and Gastrulation?
- Both Neurulation and Gastrulation take place during embryogenesis.
- Both take place in the endometrium.
- Both lead to differentiation of the embryo.
What is the Difference Between Neurulation and Gastrulation?
Neurulation vs Gastrulation |
|
| Neurulation is the initial step of the development of the nervous system, where it gives rise to the neural plate that develops into a neural tube, finally giving rise to the spinal cord and the brain. | Gastrulation is the process of development of three germ layers namely ectoderm, endoderm, and mesoderm. |
| Time Period | |
| Neurulation occurs in 14th to 17th day after fertilization. | Gastrulation occurs in 7th to 14th day after fertilization. |
| Previous Stage | |
| Gastrulation is followed by neurulation. | Blastulation is followed by gastrulation. |
| Developing Structures or Layers | |
| The neural tube, brain, and spinal cord are produced in neurulation. | The germ layers – ectoderm, endoderm, mesoderm are produced in gastrulation. |
Summary – Neurulation vs Gastrulation
Neurulation and Gastrulation are two processes observed during embryogenesis. Neurulation is the process of developing the neural tube leading to the development of the brain and the spinal cord. Gastrulation, in contrast, occurs prior to the Neurulation process. Gastrulation is the process of developing the germ layers including ectoderm, endoderm, and mesoderm. This is the difference between neurulation and gastrulation.
Reference:
1.Purves, Dale. “The Initial Formation of the Nervous System: Gastrulation and Neurulation.” Neuroscience. 2nd Edition., U.S. National Library of Medicine, 1 Jan. 1970. Available here
2.Slonczewski, Joan. “Animal Development: Neurulation and Organogenesis.” Chapter 14. Gastrulation and Neurulation. Available here
Image Courtesy:
1.’2912 Neurulation-02’By OpenStax College – Anatomy & Physiology, Connexions Web site. Jun 19, 2013. (CC BY 3.0) via Commons Wikimedia
2.’Blastula’By Abigail Pyne – Own work, (Public Domain) via Commons Wikimedia