Movies from Ear Research

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Human neural progenitor cells differentiating on a MEA

A picture from a movie: Human neural progenitor cells differentiating on a MEA
Seven day time-lapse video recording showing human neural progenitor cells differentiating on a Multi Electrode-Array (MEA). The non-transparant squares are electrodes through which cells can be electrically stimulated as well as monitored for spontanous electrical activity. As the cells mature several axons sprout and form bundles between neighboring cell clusters thus creating a neural network before our eyes.
 

Axon sprouting in a cultured regenerating auditory nerve 

A picture from a movie: Axon sprouting in a cultured regenerating auditory nerve
A time lapse video recording shows a regenerating auditory neuron with axon sprouting. One image is taken every third minute to make a movie. The movie is displayed in normal speed and shows the movements of the nerve. Cells are cultured in a plate coated with laminin and ornithine together with nerve growth factors such as BDNF, NT3 and GDNF. The nerve is attracted by a nearby located neuron and fasciculate. An adjacent glia cell is chemically attracted. 

The formation of an auditory nerve ganglion 

A picture from a movie: The formation of an auditory nerve ganglion
A time lapse movie showing the formation of an auditory nerve ganglion. Ten neurons, which have been dissociated, are cultured together with glia cells in medium Neurobasal together with nerve growth factors BDNF, NT3 and GDNF. The cells are followed for 10-14 days. One image is taken every 3rd minute and the frames are put together into a movie. The cell movements can be readily observed. The round cells are neuron cell bodies. They can be observed to "sprout" or project neurites or axons into the surrounding. The tip of the neurites is called growth cone and it decides the direction and growth of the axon. The growth cones can interact with other neurons and form bundles of nerve axons. This process is called fasciculation. It seems as if the growth cones can signal to each other without physical contact. Some cones seek other cells through chemical attraction or chemotaxis. One cone attaches to another axons and "pulls" it to another axon in order to form nerve bundles. At the same time cell bodies move together and form a ganglion (translocation). The growth cone acts as an architect. The movie shows that it is possible to transplant neurons into a deficient auditory nerve and that these new neurons can integrate among the host neuron.

There are progenitor/stem cells in the adult human inner ear that can form new nerve cells

A picture from a movie: There are progenitor/stem cells in the adult human inner ear that can form new nerve cells
A time lapse video recording of a human auditory nerve progenitor cell. The movie shows that even in the adult human inner ear there are progenitor/stem cells present that can form new nerve cells. The result has been verified in other experiments at our laboratory. The cell can be seen to retract its processes and undergoes cell mitosis. Two identical neurons are formed. Note that the nuclei undergo so-called translocation and migrates along the axonal shaft. Note also that a small cytoplasmic bridge is maintained between the two nerve cells long time after cell division. Can the neuron theory be challenged?  

A human cochlear neurosphere

A picture from a movie: A human cochlear neurosphere
A time lapse video recording of a human cochlear neurosphere. It contains progenitor/stem cells.

The immunoreactivity of connexin 26 and connexin 30 in a human organ of Corti 

A picture from a movie: The immunoreactivity of connexin 26 and connexin 30 in a human organ of Corti
Video confocal immunohistochemistry showing the immunoreactivity of connexin 26 (red) and connexin 30 (green) in a human organ of Corti. Dominating connexin is 30 which are particularly abundant in the Hensen cells.

Time lapse video recording of glia cell adherence to in vitro cultured auditory neuron in the presence of GDNF

A picture from a movie: Time lapse video recording of glia cell adherence to in vitro cultured auditory neuron in the presence of GDNF
Time lapse video recording of glia cell adherence to in vitro cultured auditory neuron in the presence of GDNF

The effect of guidance molecule netrin 1

A picture from a movie: The effect of guidance molecule netrin 1
A time lapse video recording showing the effect of guidance molecule netrin 1 on the growth cone in a vitro cultured auditoey neuron. Netrin 1 was injected to the left of the cone which deviates to the left and also bifurcates into two axons.

When netrin 1 is given behind the cone

A picture from a movie: When netrin 1 is given behind the cone
The recording shows corresponding action when netrin 1 is given "behind the cone". This guidance molecule results in the arrest or halt of the cone which becomes bulbar in shape.

The growth cone of an in vitro cultured auditory neuron

A picture from a movie: The growth cone of an in vitro cultured auditory neuron
A time lapse video recording of the growth cone of an in vitro cultured auditory neuron. Suddenly the neuron undergoes rapid disintegration or apoptosis. An adjacent glia-like cells starts to engulf the degenerated neuron.

3D-network of spiral ganglion neurons

A picture from a movie: 3D-network of spiral ganglion neurons
3D-network of spiral ganglion neurons growing inside an extracellular matrix gel stained with nuclear staining DAPI (blue) and with immunofluorescence against neural marker Tuj1 (Green). Images were taken using confocal microscopy.


 

Why you should not drink during pregnancy 

A picture from a movie: Why you should not drink during pregnancy.
Imagine the brain of a human fetus developing, millions of nerve cells seeking their way to get the right connections to form a fully functioning human, then imagine the mother drinking alcohol which slips through the placenta into the blood stream of the fetus. This video gives you an indication of what happens when the growing nerves are exposed to alcohol.

This time-laps video shows a nerve cell growing in a culture dish mounted in a microscope. The microscope follows the cell as it grows for several hours taking a picture every three minutes.

At certain time points a small amount of alcohol is added to the culture media (indicated by an arrow) by a microinjection close to the cell and it is remarkable to see the instant reaction from the growth cone, which stops growing and even regresses. Keep in mind that this growth cone is seeking contact with other neurons like it would in vivo, and the nerve would have the same reaction there, as would its human analog. The amount of alcohol added is just 6 thousand of a thousandth of a liter but it is enough to re-route the nerve forever. Think about this the next time you see a pregnant woman having "just a little wine".

On a more detailed note, the culture plate was poly-L-ornithine coated. The culture medium was Neurobasal supplementet with BDNF, NT3 and GDNF. The incubator was set for 37°C and 5% CO2.