topic 1 (brain cells and types) Flashcards
How many neuronal cells are there in the human brain?
85 billion
how many non neuronal cells are there in the human brain?
85 billion
what percentage of the cell is water and what percentage is organic/inorganic molecules?
70% water
30% organic/inorganic molecules
how many human genes does DNA code for per cell?
23,000
how many protein molecules are there per cell?
42 million
how many lipid molecules are there per cell?
1000
what different molecules are there in each cell?
nucleic acids
proteins
lipids
polysaccharides
inorganic ions
water
what is the most abundant molecule in the cell?
proteins
what are the two stages of DNA coding for protein
Transcription- DNA making a messenger RNA molecule
Translation- mRNA being translated into a protein
what is guanine always opposite?
cytosine
what is adenine always opposite
thymine
how many amino acids are there?
22
what does phosphoryation/dephospohrylation do?
phosphorylation and dephosphorylation can be used by a cell to switch on and off the function of a protein
what is a cytoskeleton?
- a system of filaments or fibres present in the cytoskeleton
- it maintains the cells shape and helps with the movement of organelles within the cell
what is the proteasome?
-a large protein complex responsible for the degradation of intracellular proteins
- they degrade unneeded or damaged proteins
- they do this by proteolysis- a chemical reaction that breaks protein bonds
what are 5 major cell types of the brain?
- neurons
- astrocytes
- oligodendrocites
- migroglia
- endothelial
what are 7 additional minor cell types of the brain?
- smooth muscle
- pericytes
- vascular leptomeningeal cells
- epyndemal cells
- epithelial cells
- lymphocytes
- schwann cells
what does post-mitotic mean?
they do not divide any further
what is apoptosis?
programmed cell death
what is a protein uniquely expressed by neurons?
neurofilament proteins
what is the developmental origin of oligodendrocytes?
the neuroectoderm
what cells do oligodendrocytes develop from?
neuronal stem cells and oligodendrocyte progenitor cells
what are the express marker proteins of oligodendrocytes?
NG2, olig1, MBP, PLP, MOG
what is the origin of astrocytes in the neural tube?
the neuroectoderm
what are 5 functions of astrocytes?
- regulation of synaptic connectivity
- regulation of neurotransmitter homeostasis in the extracellular space
- they link together in a network at the edge of cappileries to help form the blood brain barrier
- they help guide circuit formation during development
- they are involved in wound healing and limitation of inflammation
what are the express markers of astrocytes?
GFAP, vlimentin, GLAST
where do microglia develop from?
- myeloid progenitors in the blood island in the yolk sac
- they are formed from the first wave of haemopoeisis
what are the functions of microglia?
- they eat dying or dead cells
- they kill and engulf pathogens
- they have been shown to nibble the membranes of neuronal cells as part of normal brain function. This potentially impacts the remodelling of synaptic neural networks
what is the main express marker protein of microglia?
iba-1
