Final Exam Flashcards
Function of Tanycytes
Line the 3rd ventricle and extend to the hypothalamus (signal from CSF to CNS)
What are the 4 types of glial cells?
- Microglia
- Oligodendrocytes/Schwann Cells
- Astrocytes
- Ependymal (including radial glia)
What kind of cell acts as a stem cells? What does this mean?
Radial glia. They produce neuronal progenitors that become astrocytes during development.
What glial cells are phagocytotic?
Microglia
What glia cells act as scaffold for neurons to migrate along during brain development?
Radial glia
Blood flow regulation with astrocytes vs pericytes.
Astrocytes - regulate blood flow by controlling arteriole diameter
Pericytes - regulate blood flow by controlling capillary diameter
Key functions of astrocytes.
K+ regulation
Removal of glutamate/GABA
Blood brain barrier
Key function of ependymal cells.
Line ventricles
Key function of microglia.
Immune function
Sense injury and clear debris
How do glial cells act in a coordinated fashion?
Astrocytes are connected by gap junctions and by diffusion of gliotransmitters released in a calcium dependent manner can act in a coordinated fashion.
What are the 4 regions of a neuron with distinct roles in the generation and communication of signals between neurons?
- Soma
- Axon (and axon collaterals)
- Dendrites
- Presynaptic release sites
What is the significance of afterhyperpolarization?
Action potential is below normal resting potential, therefore there is a refractory period where it is hard/impossible to fire another action potential.
Key features of dendrites.
Contain ribosomes - can make proteins/peptides locally
Varying diameter - thick proximal and thin distal
Actin filaments - can grow and shrink
What are the two ways thalamic relay neurons can fire?
Tonic - follow sensory input/pass input along
Burst - ignores input and fires rhythmically
Key features of the soma.
Metabolic center
Lots of ER - protein production
Lots of mitochondria - energy
Key features of axons.
Contain microtubules and microtubule binding proteins - anterograde and retrograde transport
No actin
Where can axon-axonic signaling occur?
At places where there is no myelin, but not at the Nodes of Ranvier because there aren’t any receptor sites.
What controls the about of signal released?
Calcium influx into the presynaptic terminal
How does fluorescence work?
Photon moved to an excited state
Slightly lower energy release when photon leaves excited state
Ex. blue can send a photon to excited state and green can be released when photon is released from excited state
What is the relationship between mitral cells and granule cells?
Mitral cell dendrites release glutamate that activate the receptors on the granule cell spines, which release GABA onto the mitral cells.
Convergence vs Divergence
Convergence - the number of neuronal inputs converging to a single neuron
Divergence - number of neurons on to which one neuron synapses