Block 1 Flashcards
perikaryon
soma; the cell body which structured in a way that promotes high levels of gene transcription, protein synthesis and energy production
nucleus
where DNA is transcribed to RNA
ribosomes
location of translation
Nissl bodies
clumps or stacks of rough endoplasmic reticulum
Golgi complex
protein modification and packaging
smooth endoplasmic reticulum
a tubular network forming an internal transport system
-contains enzymes for lipid and steroid synthesis and carbohydrate metabolism
mitochondria
energy production
-location of Kreb’s cycle and electron transport chain
nucleolus
The nucleolus is located in the nucleus and makes ribosomal subunits from proteins and ribosomal RNA, also known as rRNA
microtubules
cytoskeletal proteins that are the “tracks” that vesicles are moved along by small proteins
- are approximately 20 nm
neurofilaments
give the neuron “stiffness”
microfilaments
- have become synonymous with actin
- contractile protein important for motility (like in growth cones in development), neurotransmission, and plasticity
The Law of Dynamic Polarization
- Cajal
- the neuron receives information at the dendrite and transmits information at the axon
- *there are many exceptions to this
Light Microscope can resolve structures from ____. This is used in neuroscience to see _____
.2 microns = 2 * 100* nm = 2*1000 angstroms. Light miscroscope can be used with Nissl stains and Golgi stain and myelin stain to study cytoarchitecture.
Nissl stains and Light Microscopy can be used to study
identify brain sites that have been experimentally manipulated (lesion or electrode)
Why can Electron Microscopes resolve objects that are smaller or even closer together than LM?
electrons have shorter wavelengths than photons.
-electron microscopes can resolve 2-3 nm.
Retrograde tracing
- used to determine the afferents to a region
- tracer is injected that selectively binds to surface glycoproteins on axons, is endocytosed and transported back to soma
collateralization
axonal branching patterns
anterograde tracing
- used to determine the efferents from a region
- inject a tracer that selectively binds to glycoproteins on soma and dendrites, gets taken up by endocytosis and transported out the axons
name the 3 distinct germ layers
- ectoderm
- the mesoderm
- endoderm
neurulation begins with ___ and ends with ___
- thickening of the neural plate
- ends with closure of the neural tube at the neuropores
what induces the head process in the early ectoderm to thicken?
the notochord (a mesoderm structure)
the anterior neuropore closes at
24 days
the posterior neuropore closes at
26 days
failure of the neural tube to close at anterior neuropore causes
anencephaly
-most still born, but either way not sustainable to life
failure of the neural tube to close at the posterior neural tube results in
spina bifida
somites
- segmented collections of mesodermal cells
- will make up muscles, skeleton, and connective tissue
- each somite will eventually develop connections with individual spinal cord segments
cells of neural crest give rise to
sensory neurons of PNS and postganglionic autonomic motor neurons
-also give rise to Schwann cells and meningeal cells
cells of neural tube give rise to
- somatic motor neurons
- preganglionic autonomic motor neurons, and all interneurons
- also give rise to astrocytes and oligodendrocytes
where do the neurons of the neural tube develop from?
neuroepithelium in the ependymal layer
radial glial cells
- guide migrating neurons to their appropriate positions
- when job is done they will differentiate into astrocytesd
name the 3 layers of the early neural tube
- ependymal
- mantle
- marginal
where does neuronal migration end in spinal cord?
- ends in mantle layer which will become the gray matter
- white matter (marginal) develops external to gray matter (mantle)
where does neuronal migration end in the brain
-continues into the marginal layer
-In cerebellar and cerebral cortices:
gray matter develops external to white matter
sulcus limitans
-limiting groove that develops at 4-6 weeks which divides the alar plate from the basal plate
alar plate
contains interneurons that receive input from axons of sensory neurons
basal plate
- ventral
- contains cell bodies of motor neurons
basal
=ventral=motor=efferent
alar
=dorsal=sensory=afferent
encephalization
expansion of brain in developing embryo
at 4 weeks, what are the 3 main bulges or vesicles
prosencephalon, mesencephalon, and rhombencephalon