The Castro lab seeks to investigate non-canonical mechanisms of action for endogenous opioids in affective neural circuits and peripheral metabolic organs. To achieve this goal, my laboratory uses a wide array of tools to isolate endogenous opioid mechanisms of action to understand how different brain areas and circuits function in vivo. For example, we use three-dimensional anatomical mapping via multiplexed in situ hybridization or immunohistochemistry to identify how opioids and their receptors are expressed or coexpressed with single cell resolution. We also employ selective genetic knockdown or rescue, opto- and chemogenetics, in vivo fiber photometry, 1-photon endoscopic imaging, and CRISPR-Cas9 techniques to isolate the primary mechanism through which opioids causally modulate systems of interest. Currently, my lab is examining how endogenous opioids shape affective or motivated behaviors across multiple neural circuits. Areas of particular interest include like nucleus accumbens insular cortex, orbitofrontal cortex, and periaqueductal gray nucleus. We are also looking at how endogenous opioids interact with other neurochemicals (e.g., GABA/glutamate) to shape neural and behavioral outputs to better understand how opioids function as neuromodulators. Beyond the brain, we are investigating the mechanisms underlying opioid regulation of metabolism in peripheral tissues. Specifically, we are using genetic, CRISPR, optogenetic, and non-invasive near-infrared imaging approaches to isolate how opioids control insulin secretion and glucose homeostasis in endocrine pancreas. Alongside these hypothesis driven studies, my lab is also interested in expanding the scope of existing technologies to better study neuropeptides. This has taken the form of the development of wireless optofluidic platforms, novel biosensors, and multiplexed dual color endoscopic imaging. Altogether, my lab seeks to understand how endogenous opioid systems regulate a variety of systems by using and developing cutting-edge technologies.

• Lab website