Activated CDC-42 Kinase inhibitors were tested on neurons in vitro to examine their effects on axonal growth. Neurons were cultured and treated with different inhibitors (MG-5, MG-9, MG-10) as well as controls. The neurons were then stained, imaged using a microscope, and analyzed using ImageJ software to measure axon length. Results showed that neurons treated with MG-5 had increased axon length compared to controls and other inhibitors. Future work could explore how varying tubulin concentrations affects axon growth and determine why some neurons extend further than others.

1. The effects of Activated CDC-42
Kinase inhibitors on axonal growth of
neurons in vitro
Montasir Rahman
Bronx High School of Science
Mentor: Dr. Ijaz Ahmed
Medgar Evers College of CUNY

2. Introduction
Paralysis is often caused by
shortening of neurites.
Amino acid solutions from the
external environment are capable of
inducing increased neurite outgrowth
(Patel 2011)
Adding ACK1 to the cultured
neurons could cause the neurons to
experience chemotropism towards
these chemicals (La Torre 2013)
Normal Spinal Neuron Affected Spinal Neuron

3. Why “Inhibitors” for neuronal growth?
neuronal apoptosis--programmed cell death
--often triggered by inappropriate activation of CDC kinases.
Therefore, inhibitors can prevent the unnecessary activation of
these kinases, thereby reducing instances of neuronal
apoptosis.

4. Zeiss Compound
Microscope w/ 514 nm
fluorescence filter (20x
magnification).
Neurons illuminated
by Hoechst Stain
33342
1 μm
Procedure
-Commercial cultures kept in
well plates, treated with
phosphate buffered saline,
detergent, and Hoeschst stain.
*note: sample image used

5. Axonal Length Measured with ImageJ
ImageJ computer
program was used to
conduct
measurements.
The image on the
left is 3 μm by 3 μm

6. Axon Length(μm)
MG-8
2
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
CONTROL
CONTROL+DMSO
MG-5
MG-9
MG-10

7. Conclusion
•MG-5 treated neurons showed an increase in neurite length.
•Samples of MG other than that MG-5 will cause a decrease
in length.

8. Future Work
Testing to see why certain neurons will take further advantage of growth space
while others do not, possibly due to individual genetics of each neuron,
creating a ‘survival of the fittest’ scenario at the molecular level.
Tubulin plays an essential role in the growth mechanism of neurons (Hjorth
2014). Those neurons that had a greater access to the tubulin exposed to them
were able to grow at a more rapid rate. We can test if varying concentrations
of tubulin can cause increases in axon growth.

9. References
Hjorth, J.; van Pelt, J.; Mansvelder, H. D.; van Ooyen, A. (2014). Competitive Dynamics During Research
Driven Neurite Outgrowth. Public Library of Science, 9 (2), 1-10
La Torre, A. (2013), A role for the tyrosine kinase ACK1 in neurotrophin signaling and neuronal extension and
branching, Nature, 99, 10-38
Janulevicius, A.; van Pelt, J.; van Ooyen, A. (2006). Compartment Volume Influences Microtubule Dynamic
Instability: A Model Study. Biophysical Journal, 90, 788-798
Patel, K. (2011). Analysis of Neurite Outgrowth in Cultured Primary Neurons. Definiens
Schmitz, S. K. (2011). Automated Analysis of Neuronal Morphology, Synapse Number and Synaptic
Recruitment. Journal of Neuroscience Methods, 195, 185-193

10. Acknowledgements
Special thanks to Dr. Mohsin Patwary, Dr. Alam Nur-e-Kamal, and Dr. Ijaz
Ahmed for their overseeing of this research, and for their provisions of many
resources to allow for optimal contribution to the overall project. Further
appreciation is due to Mohammad W. Rahman and Muslima J. Khandakar for
their parental support throughout the duration of this project, and for
providing a means of transportation by which to reach the lab to conduct the
research. Much thanks is also due to Dr. Karen Fien and Dr. Robert Muratore
for providing guidance over the years in conducting research and formulating
an appropriate paper.