| FIG. 1 | The Basics of Brain Structure (Brain images courtesy of and with permission from John Detre, MD, and Paul Yushkevich, PhD, University of Pennsylvania). |
| FIG. 2 | The “Homunculus” (Artwork by Mary A. Leonard, Biomedical Art and Design, University of Pennsylvania. Brain image courtesy of and with permission from John Detre, MD, and Paul Yushkevich, PhD, University of Pennsylvania). |
| FIG. 3 | The Lobes of the Brain (Created by the author, artwork adapted by Mary A. Leonard, Biomedical Art and Design, University of Pennsylvania. Brain image courtesy of and with permission from John Detre, MD, and Paul Yushkevich, PhD, University of Pennsylvania). |
| FIG. 4 | Maturing Brain: The Brain “Connects” from Back to Front (A, C: Reprinted from N. Gogtay et al., “Dynamic Mapping of Human Cortical Development During Childhood Through Early Adulthood,” Proceedings of the National Academy of Sciences 101, no. 21 [May 25, 2004], 8174–79, copyright 2004 National Academy of Sciences, U.S.A. B: Brain image courtesy of and with permission from John Detre, MD, and Paul Yushkevich, PhD, University of Pennsylvania). |
| FIG. 5 | Multitasking Is Still Not Perfect in the Teen Brain (With kind permission from Springer Science and Business Media and the author: M. Naveh-Benjamin et al., “Concurrent Task Effects on Memory Encoding and Retrieval: Further Support for an Asymmetry,” Memory & Cognition 34, no. 1 [2006], 96, fig. 3A, © 2006). |
| FIG. 6 | Anatomy of Neuron, Axon, Neurotransmitter, Synapse, Dendrite, and Myelin (Created by the author, artwork by Mary A. Leonard, Biomedical Art and Design, University of Pennsylvania). |
| FIG. 7A | Inhibitory Cells Can Stop Signaling (Created by the author, artwork by Mary A. Leonard, Biomedical Art and Design, University of Pennsylvania). |
| FIG. 7B | Excitatory and Inhibitory Synapses (Created by the author, artwork by Mary A. Leonard, Biomedical Art and Design, University of Pennsylvania). |
| FIG. 8 | The Young Brain Has More Excitatory Synapses Than Inhibitory Synapses (Courtesy of and created by the author). |
| FIG. 9 | Gender Differences in Rate of Cortical Gray Matter Growth (Reprinted with permission from Macmillan Publishers Ltd./Nature Neuroscience: J. N. Giedd et al., “Brain Development in Children and Adolescents: A Longitudinal Study,” Nature Neuroscience 2, no. 10 [1999], 861–63, © 1999). |
| FIG. 10 | Long-Term Potentiation (LTP) Is a Widely Used Model of the “Practice Effect” of Learning and Memory (Created by the author, artwork adapted by Mary A. Leonard, Biomedical Art and Design, University of Pennsylvania. Brain image courtesy of and with permission from John Detre, MD, and Paul Yushkevich, PhD, University of Pennsylvania). |
| FIG. 11 | New Receptors Are Added to Synapses During Learning and Memory and Long-Term Potentiation (Created by the author, artwork adapted by Mary A. Leonard, Biomedical Art and Design, University of Pennsylvania). |
| FIG. 12 | Gray Matter and White Matter Develop Differently Throughout Life (Courtesy of and with permission from Arthur Toga, Institute of Neuroimaging and Informatics, Keck School of Medicine, University of Southern California). |
| FIG. 13 | Adolescents’ Synaptic Plasticity Is “Way Better” Than Adults’ (Reprinted from N. L. Schramm et al., “LTP in the Mouse Nucleus Accumbens Is Developmentally Regulated,” Synapse 45, no. 4 [Sept. 15, 2002], 213–19, copyright © 2002 Wiley-Liss, Inc.). |
| FIG. 14 | The Developmental Control of the Circadian System (Reprinted from M. H. Hagenauer and T. M. Lee., “The Neuroendocrine Control of the Circadian System: Adolescent Chronotype,” Frontiers in Neuroendocrinology 33, no. 3 [Aug. 2012], 211–29, © 2012, with permission from Elsevier and the author. Additional artwork by Mary A. Leonard, Biomedical Art and Design, University of Pennsylvania). |
| FIG. 15 | Ventral Tegmental Area (VTA) Dopamine Neurons from Young Mice Are Able to Fire More Action Potentials Than Those from Adult Mice When Stimulated (Reprinted from A. N. Placzek et al., “Age Dependent Nicotinic Influences over Dopamine Neuron Synaptic Plasticity,” Biochemical Pharmacology 78, no. 7 [Oct. 1, 2009], 686–92, © 2009, with permission from Elsevier. Additional artwork by Mary A. Leonard, Biomedical Art and Design, University of Pennsylvania). |
| FIG. 16 | Rates of Alcohol, Cigarette, and Illicit Drug Use from the National Institutes of Health (Courtesy National Institute of Drug Abuse, a component of the National Institutes of Health, U.S. Department of Health and Human Services. Adapted by Mary A. Leonard, Biomedical Art and Design, University of Pennsylvania. Available at http://www.drugabuse.gov/sites/default/files/nida_mtf2012_infographic_1_1000px_3.jpg). |
| FIG. 17 | Shared Synaptic Biology of Learning and Addiction (Artwork by Mary A. Leonard, Biomedical Art and Design, University of Pennsylvania). |
| FIG. 18 | The Adolescent Brain Responds to Nicotine More Robustly Than the Adult Brain (Reprinted from T. L. Schochet et al., “Differential Expression of Arc mRNA and Other Plasticity-Related Genes Induced by Nicotine in Adolescent Rat Forebrain,” Neuroscience 135, no. 1 [2005], 285–97, © 2005, with permission from Elsevier. Additional artwork by Mary A. Leonard, Biomedical Art and Design, University of Pennsylvania). |
| FIG. 19 | Alcohol Decreases LTP (A: Reprinted from T. A. Zhang et al., “Synergistic Effects of the Peptide Fragment D-NAPVSIPQ on Ethanol Inhibition of Synaptic Plasticity and NMDA Receptors in Rat Hippocampus,” Neuroscience 134, no. 2 [2005], 583–93, © 2005, with permission from Elsevier. B: Created by the author, artwork by Mary A. Leonard, Biomedical Art and Design, University of Pennsylvania). |
| FIG. 20 | Alcohol Affects LTP in Adolescents More Than in Adults (Reprinted from G. K. Pyapali et al., “Age and Dose-Dependent Effects of Ethanol on the Induction of Hippocampal Long-Term Potentiation,” Alcohol 19, no. 2 [Oct. 1999], 107–11, © 1999, with permission from Elsevier. Additional artwork by Mary A. Leonard, Biomedical Art and Design, University of Pennsylvania). |
| FIG. 21 | Increases in Marijuana and Substance Abuse in Teens in the Last Decade (A: Adapted from National Monitoring the Future Study 1997–2011 by Mary A. Leonard, Biomedical Art and Design, University of Pennsylvania. Available at http://files.eric.ed.gov/fulltext/ED529133.pdf. B: Courtesy of Substance Abuse and Mental Health Services Administration, Department of Health and Human Services, National Treatment Episode Data Set 2007, adapted by Mary A. Leonard, Biomedical Art and Design, University of Pennsylvania. Available at http://www.samhsa.gov/data/DASIS/TEDS2k7AWeb/TEDS2k7AWeb.pdf). |
| FIG. 22 | Effects of Cannabinoids on Learning. (A: Reprinted by permission from Macmillan Publishers Ltd.: N. Stella et al., “A Second Endogenous Cannabinoid That Modulates Long-Term Potentiation,” Nature 388 [Aug. 21, 1997], 773–78, © 1997. B: Artwork by Mary A. Leonard, Biomedical Art and Design, University of Pennsylvania). |
| FIG. 23 | Long-Term Effects of Marijuana on Gray and White Matter in the Teen Brain. (A: Reprinted with permission from M. H. Meier et al., “Persistent Cannabis Users Show Neuropsychological Decline from Childhood to Midlife,” Proceedings of the National Academy of Sciences 109, no. 40 [Oct. 2, 2012], E2657–64, copyright 2012 National Academy of Sciences, U.S.A. B: Reprinted with permission from D. Arnone et al., “Corpus Callosum Damage in Heavy Marijuana Use: Preliminary Evidence from Diffusion Tensor Tractography and Tract-Based Spatial Statistics,” NeuroImage 41, no. 3 [July 1, 2008], 1067–74, © 2008, with permission from Elsevier). |
| FIG. 24 | Enhanced Effects of Cocaine on the Behavior of Adolescent Rats. (Reprinted from A.L. Wheeler et al., “Adolescent Cocaine Exposure Causes Enduring Macroscale Changes in Mouse Brain Structure,” Journal of Neuroscience 33, no. 5 [Jan. 30, 2013], 1797–1803a, with permission from Society for Neuroscience. Additional artwork by Mary A. Leonard, Biomedical Art and Design, University of Pennsylvania). |
| FIG. 25 | Stress Can Decrease Learning and LTP. (A, C: Artwork by Mary A. Leonard, Biomedical Art and Design, University of Pennsylvania. B: Created by the author, artwork by Mary A. Leonard, Biomedical Art and Design, University of Pennsylvania. D: Reprinted with permission from M. R. Foy et al., “Behavioral Stress Impairs Long-Term Potentiation in Rodent Hippocampus,” Behavioral and Neural Biology 48, no. 1 [July 1987], 138–49, © 1987, with permission from Elsevier. Additional artwork by Mary A. Leonard, Biomedical Art and Design, University of Pennsylvania). |
| FIG. 26 | Enhanced Response to Fearful Stimuli in Adolescents Compared with Children and Adults. (Reprinted from B. J. Casey et al., “Transitional and Translational Studies of Risk for Anxiety,” Depression and Anxiety 28, no. 1 [Jan. 2011], 18–28, © 2011 Wiley-Liss Inc.). |
| FIG. 27 | Prior Juvenile Diagnoses in Adults with Mental Disorders. (Reprinted from J. Kim-Cohen et al., “Prior Juvenile Diagnoses in Adults with Mental Disorder: Developmental Follow-Back of a Prospective-Longitudinal Cohort,” Archives of General Psychiatry 60, no. 7 [July 2003], 709–17, copyright © 2003 American Medical Association. All rights reserved). |
| FIG. 28 | Gender Differences in Brain Connections (Reprinted with permission from M. Ingalhalikar et al., “Sex Differences in the Structural Connectome of the Human Brain,” Proceedings of the National Academy of Sciences 111, no. 2 [Jan. 14, 2014], 823–28, copyright 2014 National Academy of Sciences, U.S.A.). |
| FIG. 29 | How Accountable Should Society Hold Adolescents? (Justice John Paul Stevens, United States Supreme Court; Steve Drizin, Northwestern University in Chicago; www.fairsentencingofyouth.org). |
| FIG. 30 | A Recap of Brain Development and the Critical Stage of Adolescence (Courtesy of the author). |
