Definitions #2 Flashcards
(20 cards)
Neurite
cytoplasmic process of a neurone e.g. axons + dendrites
Filopodia
thin membrane protrusions that acts as antennae for cell to probe surrounding environment
Name the three parts of the axonal growth cone.
~ central domain
~ transitional zone
~ peripheral domain
Neuroplexins
single transmembrane receptors that work as dimers + need co-receptor plexus as don’t have signal transduction system
Plexins
co-receptors to neuroplexins that trigger novel signal transduction pathway that controls repulsion (cause microtubule disassembly + actin depolymerisation = growth cone collapse)
Semaphorin 3
secreted by ventral part of dev. spinal cord to repel thermoreceptor + pain receptors neurites, sensory muscle neurones not affected
SAMs
a.k.a. substrate adhesion molecules
important extracellular matrix adhesion molecules
Agrin
causes clustering of Ach receptors
ARIA
causes production of new Ach receptors
Cerebral cortex
outer layer of cerebrum composed of folded grey matter
Radial glial
microglial cells that attach their processes to different surfaces forming a scaffolding upon which other cells migrate
Name 4 functions of cerebral cortex.
1) personality
2) planning + organisation
3) processing sensory info
4) intelligence
Name the 6 layers of cerebral cortex.
1) molcular layer
2) external granular
3) external pyramidal
4) internal granular
5) internal pyramidal
6) fusiform
Reelin
an extracellular matrix-associated glycoprotein secreted by Cajal-Retzius cells
Cajal-Retzius cells
marginal zone cells that have ascending processes that contact the pial surface and a horizontal axon pleus + secrete reelin
Lissencephaly
~ brain surface is smooth due to failure of neural migration
~ severe neurological impairments + intractable seizures
Pachygyri
~ where the convolutions of the brain surface are broad, shallow and reduced in number due to a migrational defect
~ severe neurological impairments + intractable seizures
Polymicrogyria
~ numbers small gyri due to neuronal migrational interference
~ moderate-severe neurological impairments depending on extend of malformation
Cortical heterotopias
~ islands of neurons in abnormal locations due to migrational arrest
~ extend of heterotopia determines degree of neurological impairment + seizures
GAL4/UAS system
a method for activating gene expression in Drosophila
