Bio Lab Prac 1 Notes

Slide 1

Pyramidal cells

• - primary information carrying neurons of the cerebral cortex + densely found in the hippocampus
• -responsible for cognition
• -projection neurons (communicate info to other parts of the brain) in contrast to local interneurons which influence local areas.
• -Dendrites of pyramidal cells are cover in small bumps called dendritic spines that form the post synaptic surface of the cell and receive most of the excitatory postsynaptic potentials (EPSPs) --> increase surface area
• -the Plasticity in the dendritic tree and spines is thought to underlie memory formation! (e.g. rats in rich environment more branches and spines compared with those in poor environments)

Dendrite branching

• - called teh dendritic arborisation or dendritic tree

Glial Cells

• - support function of neurons + provide structure for the brain
• - old data 10:1 glial to neurons new data 1:1
• - Have cell bodies but DO NOT have voltage-dependent ion channels or fire action potentials

Glial Cells: Astrocytes

• - long, slender and relatively unbranched or short and highly branched.
• - provide physical structure and support
• - Large portion of the cerebral cortex is comprised of neuropil which incudes the processes of both neurons and neuroglialcells
• -also provide extracellular electroyte balance and nutrient transport from the blood stream
• integral in the structure and function of thte blood brain barrier

Glial cells: oligodendrocytes

• - smaller than astrocytes + have fewer processes
• - cell bodies dark and round
• -processes provide mylen sheath for axons, electrically insulating them

Peripheral Nerves

• - bundles of myelinated nerve fibers enveloped by connective tissue
• -Schwan cells