Neurooo Flashcards
General rule for neuro development signaling
1) anterolateral is most important I.e. Hox genes
2) dorso ventral is next important I.e. Sonic hedgehog
What surface are nerves made on ?
On the ventricular surface of the neural tube
Bone morphogenic protein
Made by ectoderm cells. Inhibits the formation of the nervous system. Promotes epidermal growth
Chordin and noggin
These are produced by hensons node and are responsible for blocking bone morphogenic protein. Aka this allows ectoderm cells to make nervous system
Homeotic gene
Gene that produces something that acts back on its nucleus. Aka EMX and OTX
OMX & ETX diseases
ETX leads to schizenecphaly
OMX leads to epilepsy
What determines hox expression
Retinoic acid produced by hensons node
Cell migration is dependent on what type of cells ?
Radial glial cells
What glycoprotein helps a cell travel to the appropriate cortical area?
Reelin. Cortical cells seem to recognize their extra cellular reelin signal. Reelin in the signal that tells the neuron to get off the radial glial cell
Kallman’s syndrome
Happens in make patients whose neural crest cells fail to migrate due to malformation if the olfactory placode
How do neural crest cells migrate in PNS
They migrate by pathways dictated by Laminin and other key extra cellular proteins
Leukemia inhibitory factor
Is releases by muscle cells and can change the phenotype of a cell. I.e. A cell that was supposed to be noradregernic becomes cholenergic when co cultured with the heart
Laminin
Important for neurite growth. Produced by Schwann cells. It was found when these are attacked via antibodies neurite extension and outgrowth don’t happen. Particularly important after injury
Charcot Marie tooth disease
Problem with Schwann cell not producing pmp-22 (peripheral myelin protein)
Single amino acid substitution from glycine -> aspartate
Formation of axon bundles are influenced by what ?
Cell adhesion molecules. N-cam. Neuronal cell adhesion molecules bind to itself and attracts other axons
Agrin
Protein released by a nerve that causes receptors to aggregate at the end plate
Nerve growth factor
Extracted from salivary and snake venom. This was seen to be essential for nerve growth and SURVIVAL from sensory and sympathetic neurons. Regulates synthesis of NE. Has trophic effects…only retrograde. Acts on TRK receptors. Long range trophic molecule. Has effects on sympathetic and dorsal root ganglion cells. CNS cholenergic receptors depend on NGF
How does nerve growth factor regulate the synthesis of NE ?
Just on example of what it regulates…appears to have a critical time for the development of many things. (Dorsal root ganglion development is another important example)
Induces two enzymes that are important for NE synthesis
1) tyrosine hydroxylase
2) dopamine b hydroxylase
Just one example of what it regulates
What do neural crest cells and sensory neurons of the dorsal root ganglion need for proliferation, differentiation and survival ?
BDNF or NT-3
What does the notochord help make ?
The floor plate and motor neurons
Netrin
Produced by floor plate cells and attracts dorsal horn fibers to grow to the floor plate and cross to the other side
What are the stages of neuronal development
Proliferation, migration, axon growth, cell death, synapse formation, myelination and synapse elimination with stabilization
Hensons node
Produced chordin, noggin and retonioc acid
What does retonioc acid do
Activates transcription of HOX genes. Diff parts of the body have diff sensitivities to retinoic acid.
-the diffusion of retinoic acid from hensons node establishes a gradient along the anterior posterior axis and contributes to the sequence of HOX gene expression in the hindbrain
