Related Experiment Video
Updated: Aug 5, 2026
08:01
Analysis of Developing Tooth Germ Innervation Using Microfluidic Co-culture Devices
Published on: August 14, 2015
Early development of the mesencephalic trigeminal nucleus
1MRC Centre for Developmental Neurobiology, Guys Campus, Kings College London, London, United Kingdom.
Summary
The mesencephalic trigeminal nucleus (MTN) neurons, crucial for jaw proprioception, are not derived from neural crest cells as previously thought. Their development is regulated by Fgf-8 signaling from the isthmus.
Area of Science:
- Neuroscience
- Developmental Biology
- Cell Biology
Background:
- The mesencephalic trigeminal nucleus (MTN) comprises proprioceptive sensory neurons innervating jaw muscles, with their evolution linked to jaw development.
- These neurons are the earliest born in the mesencephalon and are unique intramedullary primary sensory neurons in amniotes.
- Little is known about the early developmental origins and regulation of MTN cells.
Purpose of the Study:
- To investigate the progenitor source and early developmental mechanisms of the mesencephalic trigeminal nucleus (MTN).
- To challenge existing perceptions regarding the neural crest origin of MTN neurons.
Main Methods:
- Utilized neural crest markers to identify MTN progenitors.
- Analyzed gene expression patterns, specifically focusing on Brn-3a.
- Investigated the role of Fibroblast Growth Factor 8 (Fgf-8) signaling through ectopic application and in vivo inhibition.
Main Results:
- Neural crest markers did not highlight MTN progenitors, suggesting a non-neural crest origin.
- MTN cells were identified by the expression of Brn-3a, located dorsally in the mesencephalon.
- Fgf-8 secreted by the isthmus was found to be crucial for MTN development, with ectopic Fgf-8 promoting and inhibition impairing its development.
Conclusions:
- The progenitors of the mesencephalic trigeminal nucleus (MTN) are not derived from the neural crest.
- Brn-3a expression marks developing MTN cells.
- Fgf-8 signaling from the isthmus is essential for the proper development of the MTN.
Related Concept Videos
01:30Neurulation
Neurulation is the embryological process which forms the precursors of the central nervous system and occurs after gastrulation has established the three primary cell layers of the embryo: ectoderm, mesoderm, and endoderm. In humans, the majority of this system is formed via primary neurulation, in which the central portion of the ectoderm—originally appearing as a flat sheet of cells—folds upwards and inwards, sealing off to form a hollow neural tube. As development proceeds, the anterior...
01:30Diencephalon: Anatomical Regions
The diencephalon, etymologically translated as 'through brain,' plays an integral role as the conduit between the cerebrum and the vast extent of the nervous system. However, the olfactory system is an exception, as it interfaces directly with the cerebrum. The diencephalon, deeply ensconced beneath the cerebrum, primarily consists of three paired structures — the thalamus, hypothalamus, and epithelamus. It also includes accessory structures such as the subthalamus, which houses the subthalamic...
01:23Diencephalon: Hypothalamus and Coordination
The hypothalamus is a small yet highly complex and essential brain region that plays a crucial role in regulating various bodily functions. Anatomically, it is located at the base of the brain, just above the brainstem and below the thalamus, forming part of the limbic system.
The hypothalamus interacts with other brain regions, including the pituitary gland, through a direct physical connection called the hypothalamic-pituitary axis. The hypothalamus receives somatic and visceral inputs and...
The hypothalamus interacts with other brain regions, including the pituitary gland, through a direct physical connection called the hypothalamic-pituitary axis. The hypothalamus receives somatic and visceral inputs and...
01:19Brainstem
The brainstem, located inferior to the brain and superior to the spinal cord, serves as a bridge between the cerebrum and the spinal cord. It plays a vital role in relaying information and controlling critical life functions. It comprises three primary regions: the midbrain, pons, and medulla oblongata.
The Midbrain
The midbrain is located beneath the diencephalon and connects the cerebrum with the lower parts of the brain. The cerebral peduncles are prominent midbrain structures that house the...
The Midbrain
The midbrain is located beneath the diencephalon and connects the cerebrum with the lower parts of the brain. The cerebral peduncles are prominent midbrain structures that house the...
01:21Brainstem: Control Centers of Medulla
The medulla oblongata is a crucial part of the brainstem responsible for controlling various autonomic and involuntary functions. It contains several nuclei, including the olivary, cuneate, gracile, and solitary nuclei.
Olivary Nucleus
The olivary nucleus, or inferior olivary nucleus, is located within the ventrolateral part of the medulla oblongata. It is primarily involved in motor coordination and motor learning. The olivary nucleus receives input from the spinal cord, cerebellum, and motor...
Olivary Nucleus
The olivary nucleus, or inferior olivary nucleus, is located within the ventrolateral part of the medulla oblongata. It is primarily involved in motor coordination and motor learning. The olivary nucleus receives input from the spinal cord, cerebellum, and motor...
01:14Cranial Nerves: Types Part I
Cranial nerves are responsible for transmitting motor and sensory information between the brain and various parts of the body. There are twelve pairs of cranial nerves, with the first six being essential in sensory perception, motor control, and autonomic functions related to the head and neck.
Olfactory Nerve (Cranial Nerve I)
The olfactory nerve, or cranial nerve I, is unique as it is purely sensory and dedicated to the sense of smell. This nerve originates in the olfactory epithelium of the...
Olfactory Nerve (Cranial Nerve I)
The olfactory nerve, or cranial nerve I, is unique as it is purely sensory and dedicated to the sense of smell. This nerve originates in the olfactory epithelium of the...