BIPOC Neuroscientist Spotlight 1: Dr. Sade Spencer
The term BIPOC means Black, Indigenous, and other People Of Color. This project aims to increase the representation of actual neuroscientists that are not included in textbooks nowadays.
Would you like to know who is actually conducting research nowadays?
Let’s find out! In this series, we are going to present four BIPOC Neuroscience Professors and Post Docs from different universities in the US. The neuroscientists in consideration are Dr. Sade Spencer, Dr. Alexandra Clark, Dr. Michael Burton, and Dr. Taraz Lee. Specifically, we will share details of their personal life, their research, and their contributions to the field. Our first neuroscientist is Dr. Sade Spencer!
Personal Life
Dr. Sade Spencer was born in Grand Prairie, Texas. Her hobbies include running and cooking, but most of the time she is focused on running her lab (https://www.spencerlabatumn.com/). Her main interests in the field of Neuroscience are the circadian clock systems, the neurochemistry and the behavior behind drug addiction, as well as teaching and mentoring. Dr. Spencer formed a heterogeneous team to work on complex research projects regarding neuroplasticity and drug addiction. Her team is formed by the postdoctoral researcher Abbey Brewer, the technician Lexi Willard, four graduate students (whose names are Mark Schonfeld, Laura Buzcek, Emma Wille, and Christian Hass) three undergraduate students, and four rotating graduate students.
Education
Dr. Sade Spencer received a B.S. in Biology at the University of Alabama in Tuscaloosa, where she also graduated Summa Cum Laude. She earned her Ph.D from the University of Texas Southwestern Medical Center in Dallas with Dr. Colleen McClung and worked at the Medical University of South Carolina with Dr. Peter Kalivas for her postdoc. Currently, she is an assistant professor at the University of Minnesota under the Pharmacology Department (https://www.spencerlabatumn.com/). At UMN, she also enjoys mentoring new faculty members that identify as female through a program known as Early Career Pathways to Success.
Research Highlights
Overview:
Dr. Spencer studies addiction and the various levels of addiction and relapse in regards to behavior and neuroplasticity of the nucleus accumbens region of the brain. She uses animal models to help her visualize the impact of drug consumption/intake during relapse stages of addiction on said neuroplasticity. Dr. Spencer is currently researching other potential impacts that could possibly occur during relapse on neural circuit function and overall long term health.
Current Research Projects:
Project 1: Studying the connection between glutamate and dopamine interactions which take place during cocaine seeking and actively taking it
Dr. Spencer studies a specific synaptic plasticity (t-SP) at glutamatergic synapses. She has discovered that consuming cocaine causes t-SP at these glutamatergic synapses to decrease as an increase in cocaine consumption causes an increase in dopamine which she has discovered, directly relates to cue-induced transient synaptic plasticity levels.
Project 2: Attempting to repurpose a type II diabetes drug to help with cocaine relapse
Dr. Spencer is studying the possibility of using metformin, typically used for helping those with type II diabetes, to lower the possibility of cocaine relapse. AMPK regulation is typically associated with nicotine and cocaine withdrawal. It is hypothesized that metformin is an indirect activator of AMPK, and the goal of the project is to prove or disprove such a notion.
Project 3: Understanding how reward and aversion of cannabinoids are encoded in the neural circuits
Dr. Spencer is researching the neural encoding of reward and aversion of tetrahydrocannabinol, attempting to discover the long term effects of cannabis use. It has been shown that while THC has a small dose-reward time, it can produce lasting neuroadaptations, similar to other drugs that can lead to drug abuse. Discovering the encoding of these factors can help development of therapies, as well as non-addictive cannabinergic drugs for medical use.
Contributions to the Field:
The Nucleus Accumbens: Mechanisms of Addiction across Drug Classes Reflect the Importance of Glutamate Homeostasis
With the understanding that continuous drug exposure interferes with the plasticity of the nucleus accumbens region of neurons, Dr. Spencer continues her research in understanding the biology or pathology behind drug seeking and addiction. Not only does she focus on the various stages of addiction, but she also studies the stages of relapse, as immediate withdrawal from continuous drug exposure causes issues in glutamatergic transmission within the nucleus accumbens. Therefore she further studies the impact that glutamate signal transduction has on various neuronal nuclei during stages of addiction and relapse along with accompanying behaviors that come along with drug addiction.
Cocaine-induced adaptations in D1 and D2 accumbens projection neurons (a dichotomy not necessarily synonymous with direct and indirect pathways)
Dr. Spencer reviews recent studies on the adaptations of D1 and D2 medium spiny neurons (dopamine-receptor expressing) in the nucleus accumbens when exposed to cocaine, including variability in synaptic plasticity, glutamate-induced signals, and changes in the morphology of dendritic spines. It is shown that cocaine actively creates enduring relapse associated neuroadaptations in the nucleus accumbens, centered around the D1 and D2 projection neurons. It is also shown that dopamine has an effect on synaptic plasticity, however the exact changes remain unclear (current studies differ between modulation and signaling bidirectional plasticity). The paper suggests that while the D1 and D2 neurons are known to be extremely important in cocaine induced neuroplasticity, further characterization is required.
Connections with NSCI 175 Course
Dr. Spencer’s research closely correlates with our course’s discussions on neurotransmitters and its association with drug consumption. Her studies of dopamine and glutamate levels at glutamatergic synapses substantially builds on our base knowledge of neurotransmitter-synapse interactions under the influence of cocaine. Specifically, this course has taught us that cocaine results in increased levels of dopamine in the synaptic cleft, thus inducing a prolonged activation of the postsynaptic cell that leads to the behavioral effects of cocaine. Moreover, the ideas we have encountered from this course regarding individual neurotransmitters can allow us to understand Dr. Spencer’s research into how these neurotransmitters interact with each other. Additionally, Dr. Spencer’s research on cannabinoid mirrors and goes beyond our understanding of these unconventional neurotransmitters. Her project investigating the neural encoding of these neurotransmitters expands on our familiarity of the behavior of cannabinoids in the synapse and the effects that THC imposes. Dr. Spencer also focuses her research on the nucleus accumbens, a brain structure that we know from NSCI 175 to be involved in the dopamine pathway. Her research aims to explain the current implications of drug abuse, considering relapse as well, further exemplifying how our course studies on addiction can serve as a background to Dr. Spencer’s projects on drug consumption.
Bibliography
Black in Neuro. (2020, July 28). Sade Spencer, PhD. https://www.blackinneuro.com/profiles/sade-spencer.
Department of Pharmacology, University of Minnesota. The Spencer Lab @ UMN. The Spencer Lab. https://www.spencerlabatumn.com/.
Scofield, M. D., Heinsbroek, J. A., Gipson, C. D., Kupchik, Y. M., Spencer, S., Smith, A. C., Roberts-Wolfe, D., & Kalivas, P. W. (2016). The Nucleus Accumbens: Mechanisms of Addiction across Drug Classes Reflect the Importance of Glutamate Homeostasis. Pharmacological reviews, 68(3), 816–871. https://doi.org/10.1124/pr.116.012484
Smith, R. J., Lobo, M. K., Spencer, S., & Kalivas, P. W. (2013). Cocaine-induced adaptations in D1 and D2 accumbens projection neurons (a dichotomy not necessarily synonymous with direct and indirect pathways). Current opinion in neurobiology, 23(4), 546–552. https://doi.org/10.1016/j.conb.2013.01.026
