Slide #22 Golgi stain of Hippocampal Pyramidal Cell

Pyramidal cells are also found in the hippocampus just as in the cerebral cortex. What is the function of the hippocampus?

Slide #23 Golgi stain of Hippocampal Pyramidal Cell--high magnification

Note the extreme density of dendritic spines! Why would hippocampal cells need so many spines? Note: Recent research suggests that rising estradiol levels in estrous females causes a temporary but substantial increase in spine density.

Slide #24 Golgi Stain of the Motor Cortex

In the middle of this slide is a large Betz cell. The apical shaft extends from the soma to the upper left-hand corner of the slide. Note the long "tap root" (desending ventrolaterally to the right from the soma).

Slide #25 Betz Cell in Infant Cortex

How many basilar dendrites do Betz cells have compared to typical pyramidal cells?

Slide #26 Nissl stain of Betz cells

Note the unusually large cell bodies here--these are the Betz cells. Where in the cortex would you find these? Error bar = 100mm. This image is from here.

Slide #27 Photomicrograph of Neuronal soma and Organelles

Neuronal Cell Body The neuronal perikaryon is occupied by a large round nucleus (Nuc) which contains homogeneously dispersed karyoplasm.  The cytoplasm contains nissl bodies (ER) or rough endoplasmic reticulum.  In addition, the cytoplasm also contains elements of the Golgi appartus (G), mitochondria (mit), free ribosomes (r) and microtubules (arrows).  A number of axon terminals (Ax) synapse with the neuron. From: Univerity of Manitoba, CA

Slide #28 Photomicrograph of Glial soma and Organelles

Microglial cells are small in comparison to astrocytes and have a dark cytoplasm and nucleus.  The reactive cell in this picture has a spherical nucleus with large clumps of chromatin beneath the nuclear envelope.  The cytoplasm is thin around the nucleus and expands at the poles of the cell.  It contains large inclusion bodies (L).  Lysosomes (Ly) and the characteristic long strands of rough endoplasmic reticulum (ER). From: University of Manitoba, CA

Slide #29 Photomicrograph of Astrocyte

Astrocytes are distinguished by their large stellate-shaped cell bodies and many radiating processes.  Some of these processes form terminal expansions (arrows) that are applied to the surface of blood vessels.  (Bv).  Fibrous astrocytes (f) are less branched and their processes radiate from the cell body for considerable distances whereas protoplasmic astrocytes (P) have more numerous and profusely branched processes.  From: University of Manitoba, CA

Slide #30 Acetylcholine Synapse

3-D structure of proteins present at acetylcholine synapse

Sample slide questions: What are the two major types of acetylcholine receptors? Which are metabotropic and which are ionotropic? What is the purpose of acetylcholinesterase?

Slide #31 Acetylcholine Receptor

Protein structure of acetylcholine receptor.

Sample slide questions: What type of acetylcholine receptor is this? What type of ion passes through it?

Slide #32 Molecular model of a synaptic vesicle

Synaptic vesicles are too small and fragile to capture and image with this level of detail. Takamori et al. (2006) used computer modeling to characterize what a synaptic vesicle would look like in three dimensions, based on what is known about more than 80 proteins embedded in the surface of these vesicles. Click on the link to the article if you are interested in seeing a list of these proteins. From: Takamori et al. (2006). Molecular anatomy of a trafficking organelle. Cell, 127, 831-846.

Sample slide questions: How many proteins involved in synaptic vesicle exocytosis do you recognize in this image? What other proteins are involved as well, and what are their roles?

Slide #33 Immunocytochemical Stain for choline acteyltransferase in the Rat Medial Septum

Cell bodies appearing pink are positively stained for choline acetyltransferase.

Sample slide questions: What is choline acetyltransferase? What does it do?

Slide #34 Immunocytochemical Stain

Immunocytochemical stain for Glial Fibrillary Acidic Proteins (GFAP) and neurofilament proteins.

Sample slide questions: What is the difference between immunocytochemistry and in situ hybridization? Between immunocytochemistry and microdialysis?

Slide #36 Cellular Endocytosis

Cells taking up red spheres by a process called endocytosis One way that cells ingest material is by a process called endocytosis. Here, in this confocal micrograph, the cells —which are labelled green with Green Fluorescent Protein (GFP) — are taking up tiny red spheres by this process. Gradually, the cell membrane extends around the sphere until it is completely enclosed. The membrane enclosing the sphere then breaks away from the edge and moves to its destination within the cell often the lysosomes — the cell’s garbage disposal units. From: Truth & Beauty

Sample slide question: What is the name of the protein that “coats” the endocytotic vesicle and assists in its transport?

Slide #37 Neurotransmitter

Fluorescence from jellyfish is used to track cell activity in space and time. This 'volume-rendered' image of a living cell is one of a series that allows us to see fluorescently-labelled packets of neurotransmitters (chemical messengers of the nervous system) in four dimensions as they move around the cell. The jellyfish green fluorescent protein is special because it does not disrupt living cells. The confocal imaging technique and image analysis software used here can reassemble individual optical sections into a complete picture of the cell and its contents as it goes about its business. For the first time these imaging techniques are being used to help us understand neurotransmitter movements in such diseases as epilepsy, schizophrenia and various psychoses. From: Truth & Beauty

Slide #38 Formation of Neuromuscular Junction

To make muscles contract, the nerves form specialized contacts with individual muscle fibres. These are called neuromuscular junctions. As they develop, multiple nerve fibres go to each muscle fibre but by some form of competition between the nerve cells all but one is eliminated. The final successful nerve is then left to send its messages to the muscle. The neurotransmitter acetylcholine (stained red) is released by the nerve cells to transmit its signals to the muscle and serves in this confocal image to highlight the region of the neuromuscular junction. From: Truth & Beauty

Sample slide question: In the plasticity lecture, we discussed several proteins that assist in the formation of the neuromuscular junction. Name and describe the functions of three of these proteins.

Slide # 39 Infant Betz Cells
Neurolucida tracings. Note the extensive dendritic arborizations of these cells, even in the infant.
Sample slide questions: Where in the cortex will you find Betz cells? What is their function?

Slide # 40 Adult Neuron of Primary Motor Cortex (BA 4)

Neurolucida tracing--what kind of cell is this?

Slide # 41A Infant Neuron of Prefrontal Cortex (BA 10)	Slide #41B Adult Neuron of Primary Motor Cortex (BA 4)
Neurolucida tracings. Although the BA4 neuron is more complex than the BA10 neuron in the infant, the reverse is true in the adult, where BA10 neurons exhibit the most complex dendritic array.

Slide # 42 Rough endoplasmic reticulum

Rough endoplasmic reticulum (RER). The dark grains are ribosomes, which are made of rRNA and are the sites for protein synthesis. From http://biyoloji_genetik.sitemynet.com

Sample slide questions: Where is rRNA made? mRNA? What is the name of the process that leads to the production of RNA?

Slide # 43 Synapses--electron microscopy

Two axo-dendritic synapses on a dendritic stem (D). The asymmetrical (Gray I) type with spherical synaptic vesicles in the presynaptic bouton and prominent postsynaptic density (S, red asterisk) on the right, the symmetrical (Gray II) type with pleiomorphic or flat vesicles in the presynaptic bouton and only slight postsynaptic density (F, blue asterisk) on the left. Scale = 200 nm. From “The Atlas of Ultrastructural Neurocytology”, http://synapses.clm.utexas.edu/

Sample slide questions: Which of these synapses is likely to be excitatory? Inhibitory? Why do you think the asymmetrical synapse has a thickened postsynaptic density?

Slide # 44 Pyramidal cell--electron microscopy

Electron micrograph of a pyramidal cell body and basilar dendrite. N = nucleus; ER = endoplasmic reticulum; G = golgi apparatus; Den = dendrite; Mit = mitochondrion; Ly = lysosome; R = ribosomes; Mt = microtubules; At = axon terminals synapsing on neuron. From Peters et al. (1991), The Fine Structure of the Nervous System: Neurons and Their Supporting Cells (3rd Ed.). New York: Oxford University Press.

Sample slide questions: Why do dendrites need to have mitochondria? Do axons also have mitochondria? Why or why not?

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