Neural Communication

The primary motor cortex, precentral gyrus, controls voluntary movement. In Joseph, the motor cortex was damaged on the right side of his brain. This side of his brain controls the left side of his body and to a lesser extent, the same side. The areas of the body, such as the hands and fingers have more cortex since they require precise movements (Garrett, 2011).

The motor neuron through the synapse tells the muscle cell to move. They are able to stimulate cells throughout the body. Information is received by way of dendrites, and once it reaches a certain threshold it creates an action potential, which pushes then information down the axon to the terminals. The terminals release neurotransmitters, which communicates the instruction and stimulates the muscle. If the neurons are damaged between Joseph’s arm and hand, his hand would not receive the information needed in order to perform.

When strokes happen, neurons can be killed out right or by starvation, by not receiving enough oxygen or nutrients in order to survive (Garrett, 2011). Damaged neurons have little ability to regenerate axons and make new connections (Garrett, 2011). When this happens, motor neurons never receive the message (impulse/stimulus). Destroyed neurons, on the other hand, cannot regenerate. The central nervous system in adults no longer produces the right conditions to promote regeneration. The glial cells produce scar tissue and this blocks the original neuron pathway. They also produce axon growth inhibitors; and the damage that has been caused triggers immune cells, which further inhibit regrowth.

Physical therapy aids the brain in reforming neural networks that control the movement of limbs. Also, compensation plays a role in that uninjured tissue assumes the functions of the damaged neurons. Within minutes of a brain injury, presynaptic neurons form additional synapses by growing more terminals and postsynaptic neurons increase their amount of receptors (Garrett, 2011). Eventually the dead neurons are removed from the body by the glia.

Stem cell treatment may be used to replace injured neurons. Embryotic stem cells can differentiate to any cell in the body (Garrett, 2011). These stem cells, when introduced into an adult nervous system, can develop into whatever neurons are needed (Maldonado-Soto et al., 2014). They have the possibility to turn into the neurons that were lost.

References

• Garrett, B. (2011). Brain and Behavior: An Introduction to Biological Psychology (3rd ed.). Los Angeles, CA: Sage. ↩1 ↩2 ↩3 ↩4 ↩5
• Maldonado-Soto, A. R., Oakley, D. H., Wichterle, H., Stein, J., Doetsch, F. K., & Henderson, C. E. (2014). Stem cells in the nervous system. American Journal of Physical Medicine & Rehabilitation / Association of Academic Physiatrists, 93(11 Suppl 3), S132–44. doi:10.1097/PHM.0000000000000111 ↩