The Team

Anjali Rajadhyaksha

Principal Investigator

Anjali received her Ph.D. in Molecular Biology from Purdue University, where she focused on transcriptional mechanisms, laying the foundation for a long-standing interest in how gene expression shapes cellular function. She broadened this molecular focus during her postdoctoral training in neuroscience at Harvard Medical School, where she began using system-level approaches to study the brain in both health and disease.

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Since establishing her lab, first at Weill Cornell Medicine in NYC and now at the Lewis Katz School of Medicine at Temple University, Anjali’s research program has expanded to span molecules, circuits, and behavior. Her team is particularly focused on how molecular signaling pathways shape neural circuit dynamics underlying substance use, neuropsychiatric, and neurodevelopmental disorders. The lab employs a multidisciplinary approach that integrates molecular biology, genetic techniques, in vivo imaging, and behavioral neuroscience to understand how disruptions in transcriptional and signaling processes lead to altered brain function and behavior.

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Outside of research, Anjali is passionate about education and mentorship. A firm believer in collaborative science, she finds deep joy in working with trainees and colleagues at all levels. Whether teaching, advising, or leading, she views mentorship as both a privilege and a responsibility.

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When she's not in the lab, Anjali enjoys being surrounded by music, whether attending live performances, building playlists with her lab members, or simply playing music in her office.

Arlene Martinez-Rivera

Assistant Professor

Arlene's primary interest as a neurobiology researcher is to understand the molecular basis of addiction. Early research experiences conducting cocaine self-administration behavioral studies in rats, and molecular work on ion channels in jellyfish, sparked her interest in science, which she deepened through a post-baccalaureate program at the University of Rochester. Arlene completed her PhD in Dr. Carmen Maldonado’s lab at the University of Puerto Rico, where she studied how mGluR5 in the nucleus accumbens regulates cocaine-conditioned behavior in rats. She then joined Dr. Anjali Rajadhyaksha’s lab as a postdoctoral fellow at Weill Cornell Medicine, where she investigated the role of L-type calcium channels in cocaine dependence using animal models. To bridge preclinical and clinical research, she earned a master’s degree in clinical epidemiology and conducted a retrospective study on repurposing LTCC blockers for treating cocaine addiction.

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Building on her training in epidemiology, she aims to conduct preclinical addiction research with strong translational potential. While in Dr. Rajadhyaksha’s lab, in collaboration with Dr. Francis S. Lee, she studied how pharmacological manipulation of the endocannabinoid system affects opioid reward and analgesia. Using conditioned place preference, self-administration, and in vivo fiber photometry recordings in mice, they found that MAGL inhibition abolishes morphine and oxycodone reward without disrupting analgesia—effects mediated by CB1 receptors, likely in the VTA. Currently, as an Assistant Professor at CSAR in direct collaboration with Dr Rajadhyaksha, her work focuses on identifying the involved neural circuits and molecular mechanisms, particularly within the RMTg–VTA–NAc pathway, as well as investigating additional effects of MAGL inhibition on opioid responses.

Mohammad Zaki Bin Ibrahim

Post Doctoral Fellow

Zaki’s interest in the Lab involves uncovering the neurocircuitry and underlying molecular mechanisms of the calcium channel Cav1.2 in social behavior, with a focus on the descending projections from the prelimbic cortex. Zaki completed his doctorate at the National University of Singapore, mentored by Dr. Sreedharan Sajikumar and Dr. Soong Tuck Wah.

His doctoral project explored the modulatory effects of CA2 on plasticity and memory consolidation in CA1 within the mouse hippocampus, employing ex vivo electrophysiology and behavioral assays. Prior to NUS, he earned his B.S. in Biological Sciences from Nanyang Technological University where he gained research experience in laboratories across Singapore, Stockholm, and Edinburgh. He remains interested in the dynamics of neural substrates underlying memory and social behavior.

Besides the lab and office, Zaki can often be found in break spaces drinking coffee and eating chocolates. A self-proclaimed daydreamer and Little Monster, he also enjoys listening to orchestral music or watching musicals — though typically not simultaneously.

Andrew Lee

Post Doctoral Fellow

Andrew is interested in studying how TCF20, a transcription factor discovered by Dr. Rajadhyaksha, regulates neural circuit development and behavior using mouse genetics and human-derived organoids. Andrew received his Ph.D. in Neuroscience from Weill Cornell Graduate School of Medical Science of Cornell University, where he studied how excitatory neurons of the cerebellar nuclei regulate circuit development and behavior in Dr. Alex Joyner and a close collaboration with Dr. Rajadhyaksha.

He showed that these neurons regulate cerebellar growth via Purkinje cell survival and SHH-mediated expansion of progenitors — a novel mechanism with implications for scaling across circuits and evolution. He also showed that early loss of the excitatory cerebellar nuclei neurons can be partially mitigated by developmental plasticity, but targeted genetic mutations produce persistent deficits and impaired circuit maturation. 

Besides the lab and office, Andrew can often be found running on the Schuylkill river trail training for his next marathon.  

Spencer Feehan

Graduate Fellow

Spencer earned a B.S. in Integrative Neuroscience from Binghamton University in New York in 2024. In his undergraduate career, Spencer worked in the lab of Dr. David Jentsch studying the effects of modulating dopaminergic projections on motivational drive in low motivated mice. Additionally, he did work on investigating the sex differences of Parkinson's caused by the loss of PINK1 on anxiety-like behaviors with Dr. Mary Kritzer at Stony Brook University.

Spencer hopes to study the molecular mechanisms underlying the importance of Cav1.2 on cocaine use disorder in the dorsal hippocampus during his PhD with Dr. Rajadhyaksha. Outside of lab, Spencer has a substantial interest in the policy and legislation surrounding drugs of abuse. In his free time, Spencer enjoys making jewelry from old silverware, reading, watching movies, and rock climbing.

Abhik Ghosh

Graduate Fellow

Abhik is researching molecular mechanisms behind CB1 and MOR crosstalk in reward circuitry, focusing on how endocannabinoid modulation can be applied to attenuate opioid reward. He graduated from New York University in 2019, receiving a B.A. with a major in Biology and a minor in History.

After his undergraduate studies, Abhik worked as an analytical chemist in a medical cannabis testing lab in Harrisburg, PA. There, he found a passion for endocannabinoid research and followed it to Temple University, hoping to help uncover the therapeutic potential behind the endocannabinoid system. Outside of the lab, he enjoys watching movies, playing video games, and cooking/trying new foods.

Charlie Maddox

Graduate Fellow

Charlie received a B.A. in Neuroscience and Visual Art from Oberlin College in Ohio in 2022. At Oberlin, they worked in the lab of Dr. Christopher Howard investigating the impact of cannabidiol (CBD) and the contribution of the dorsal striatum to habitual behavior. After graduating, they worked as a postbaccalaureate research fellow in the lab of Dr. Carl Lupica at NIDA, characterizing the activity of the lateral habenula in aversive stimulus appraisal following withdrawal from chronic Δ-9 tetrahydrocannabinol (Δ9-THC).

As a Biomedical Sciences Ph.D. student in the Lewis Katz School of Medicine at Temple University, they hope to study the neurophysiology of pain and reward processing in the context of drug addiction and withdrawal.

Outside of the lab, Charlie enjoys making art, playing TTRPGs, and long walks on the Schuylkill trail.

Sanjana Khandeshi

Laboratory Assistant

Sanjana received a B.S. in Cellular and Molecular Neuroscience and a certificate in American Sign Language was also a member of the Temple University Honors Program. Her research focuses on exploring how L-type calcium channel Cav1.2 signaling in the prelimbic cortex influences social behavior.

Previously, Sanjana studied kappa opioid receptor (KOR) signaling and its role in stress, pain, and diuresis using mouse models. Through these experiences, she has developed a strong interest in how cellular signaling pathways translate into complex behavioral outcomes and how this knowledge can inform treatments for neurological and psychiatric disorders. She plans to pursue a career in medicine, where she hopes to combine her passion for neuroscience research with compassionate patient care. 

Outside of the lab, Sanjana enjoys photography, traveling, mystery novels, playing soccer, and watching the fall colors in her hometown with her family and stubborn husky.

Leon Passarelli-Roberts

Laboratory Assistant

Leon (they/he) graduated from Temple University with a BS in Neuroscience: Cellular and Molecular and was a MARC Scholar. During undergrad, Leon spent two years in Dr. Ellen Unterwald's lab studying ketamine's effects on the PI3K/Akt/GSK3b pathway in the mouse. As one of the lab assistants in the Rajadhyaksha Lab, they primarily assist Dr. Arlene Martinez-Rivera's 2-AG project, along with helping to maintain the lab.

Outside the lab, Leon enjoys attending concerts, moshing at music festivals, and movie nights with friends. Their plans for the future include entering a neuroscience PhD, doing research that focuses on molecular mechanisms of mood disorders, like depression and ADHD.

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Andre Rei Weeks

Senior Research Manager

Andre graduated from St. Lawrence University in 2012 with a degree in Biology and a minor in Mathematics. He then earned his Master's in Public Health with a concentration in Biostatistics at SUNY Buffalo in 2015. Since then, he has worked in the field of Clinical Research for 12 years, with experience in the sponsor setting, Contract Research Organizations, and academic environments. His goal is to translate the work from the Rajadhyaksha lab into the clinical research space and collaborating with the entire Center for Substance Abuse Research.

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Outside of work, he enjoys spending time with his wife and their pets, playing American football and basketball, watching sports and films, grilling, photography, and video production. He also likes hanging out with friends, playing board and video games, and listening to music. Another big thing for Andre is training for races; he has even run 11 marathons despite hating running!