Drexel University College of Medicine

Dr. España's doctoral thesis focused on the behavioral and physiological functions of the hypocretins, particularly as they relate to arousal-related processes including sleep/wake behavior and stress. His postdoctoral research in the Department of Neurology at the Harvard institutes of Medicine focused on elucidating the afferent innervation of the hypocretin neurons with a particular emphasis on aminergic inputs. In this work, Dr. España showed that the hypocretin neurons receive input from regions that govern motivation, homeostatic drive, behavioral state, and autonomic tone.

Dr. España later joined the Department of Physiology and Pharmacology where he used behavioral and neurochemical approaches to demonstrate that the hypocretins regulate the reinforcing effects of cocaine via actions on the mesolimbic dopamine system. His current research focuses on hypocretin, dopamine, and norepinephrine regulation of arousal-related processes including sleep/wake function, stress, and drug reinforcement.

His laboratory uses a multidisciplinary approach to investigate the involvement of hypocretins in reward and addiction processes. Techniques include:

• Electrophysiological recordings of sleep/wake behavior
• Self-administration of drugs of abuse
• Fast scan cyclic voltammetry in anesthetized and freely moving preparations
• Anterograde and retrograde tracing
• Single and multi-unit recordings in behaving animals

Selected Grants Funded

K01DA025279 - Hypocretin/Orexin Modulation of Reward and Addiction Processes. These studies utilize self-administration and microdialysis techniques in behaving rats, and voltammetry in anesthetized rats to examine whether the hypocretin system influences cocaine-self administration and whether these actions involved changes in the dopamine system.

NARSAD Award - Hypocretin regulation of dopamine neurotransmission. This study will use hypocretin knockout mice to examine the extent to which the hypocretin system is necessary for normal dopamine function under normal conditions and in response to stimulant drugs of abuse.

Dr. España is an assistant professor in the Department of Neurobiology and Anatomy.