Electronic cigarettes are considered healthier alternatives to cigarettes. However, a recent study, "Mitochondrial Stress Response in Neural Stem Cells Exposed to Electronic Cigarettes," revealed the consequences of using e-cigarettes on neural development. 

Nicotine-use poses many health risks. Chapter 52: Tobacco Use Disorder in Current Diagnosis & Treatment Psychiatry, 3e, explains the methods of diagnosing nicotine addiction and the effects of tobacco ingestion. 

More specifically, stem cells have intense reactions to drugs, such as nicotine. When exposed to doses of nicotine, the cells' mitochondria undergo "stress-induced mitochondrail hyperfusion" (SIMH), which by forming clusters, acts as a protective mechanism. Even short-term use of electronic cigarettes can induce SIMH. 

The graphical abstract, provided by the study and shown below, illustrates the stem cell mitochondrial responses to different levels of nicotine. 

The levels of nicotine in electronic cigarettes are also enough to cause an influx of calcium into the mitochondria that cause them to expand and potentially break. Although SIMH is meant to increase the resilience of mitochondria, the infiltration of calcium poses a large threat to these cells. 

Especially during development, these stem cells transform into astrocytes and neurons. However, the ingestion of nicotine not only impairs development but can shorten one's life span and increase one's chances of developing a neurodegenerative disease. 

Chapter 44 of Principles of Neuroscience, 5e, extrapolates features of neurodegenerative disorders from mouse models. Figure 44-2A (below) localizes cell death according to different neurodegenerative disorders. 

Sources: 

Science Daily Article: University of California - Riverside. (2019, July 1). Study finds electronic cigarettes damage brain stem cells: UC Riverside research on mouse neural stem cells has implications for nicotine use. ScienceDaily. Retrieved July 10, 2019.

University of California -- Riverside Article:  Atena Zahedi, Rattapol Phandthong, Angela Chaili, Sara Leung, Esther Omaiye, Prue Talbot. Mitochondrial Stress Response in Neural Stem Cells Exposed to Electronic Cigarettes. iScience, 2019; 16: 250.

Graphical abstract: Atena Zahedi, Rattapol Phandthong, Angela Chaili, Sara Leung, Esther Omaiye, Prue Talbot. Mitochondrial Stress Response in Neural Stem Cells Exposed to Electronic Cigarettes. iScience, 2019; 16: 250.

Chapter 52 of Ebert, Current Diagnosis & Treatment Psychiatry, 3e: Ebert MH, Leckman JF, Petrakis IL. eds. Current Diagnosis & Treatment: Psychiatry, 3e New York, NY: McGraw-Hill; Accessed July 11, 2019.

Chapter 44 of Kandel, Principles of Neuroscience, 5e: Kandel ER, Schwartz JH, Jessell TM, Siegelbaum SA, Hudspeth AJ, Mack S. eds. Principles of Neural Science, Fifth Edition New York, NY: McGraw-Hill; Accessed July 11, 2019.

Figure 44-2: Kandel ER, Schwartz JH, Jessell TM, Siegelbaum SA, Hudspeth AJ, Mack S. Principles of Neural Science, Fifth Edition; 2014.

Figure 34-7 (cover photo): Watts RL, Standaert DG, Obeso JA. Movement Disorders, 3e; 2012.