Pleasure or Pain? He Maps the Neural Circuits That Decide. | Quanta Magazine

🌈 Abstract

The article profiles Ishmail Abdus-Saboor, an associate professor at Columbia University who studies how the brain determines whether a touch to the skin is painful or pleasurable. It covers his background, research approach, and key discoveries, including:

• Developing a new quantitative measure of pain in mice to study genetic variability and the transition from acute to chronic pain
• Identifying a pathway from the skin to the brain's reward centers that explains why some forms of touch are rewarding
• Studying naked mole rats, which do not feel some forms of pain, to potentially find new ways to block pain

🙋 Q&A

[01] Introduction

1. How did Abdus-Saboor's parents support his interest in science as a child?

• His parents supported his interest in science by getting him animals as birthday presents and allowing him to take over the third floor of their house for a yearlong science fair project in high school.
• They are not scientists themselves, but were very supportive of his "escapades and adventures in the scientific realm."

2. How did Abdus-Saboor's college experience at an HBCU shape his career?

• Attending an HBCU (historically black college) like North Carolina A&T increased his self-confidence and provided a nurturing, non-competitive environment where faculty cared about students and they worked together.
• It was a "wise decision" as he comes from a lineage of people who attended HBCUs.

3. How did Abdus-Saboor transition from studying cellular development in worms to studying pleasure and pain in neuroscience?

• As a PhD student, he studied a molecular pathway in roundworms involved in cellular development, demonstrating how these pathways control basic cell type and shape.
• He then moved into neuroscience, attracted by the many open questions and opportunities to make an impact, despite lacking formal training in the field. He proactively sought out a mentor to learn neuroscience.

[02] Developing a Pain Scale

1. How did Abdus-Saboor develop a new quantitative measure of pain in mice?

• He was dissatisfied with the traditional approach of just looking at how often an animal withdraws its paw, as this doesn't reliably indicate pain.
• He got the idea from observing high-speed videography of the acoustic startle response in zebrafish, realizing he could use a similar approach to record an animal's full movement response to a skin stimulus.
• This allowed him to assign numerical values and weights to different movement features to create a single quantitative pain scale.

2. How does this new pain scale enable Abdus-Saboor's research?

• It allows him to study genetic variability in pain sensitivity across different mouse strains and identify new pain-related genes.
• He also uses it to measure pain levels and correlate them with brain activity patterns to understand the transition from acute to chronic pain.

[03] Studying Pleasurable Touch

1. What led Abdus-Saboor to study the neuroscience of pleasurable touch?

• He read a paper showing certain skin cells responded to gentle touch, but without connecting it to natural behavior or the brain.
• As a postdoc, he genetically engineered mice to have light-responsive gentle touch neurons, planning to stimulate them and observe the mice's behavior.
• This launched a project that traced the pathway for social touch from the skin to the brain's reward centers.

2. What are the potential medical implications of understanding this skin-to-brain pathway for pleasurable touch?

• It suggests the skin could be a good therapeutic target, as the accessible touch pathway connects directly to the part of the brain that makes us feel good.
• This could potentially be used to improve mental health, for example by using a skin cream to activate these neurons and offset harms from social isolation or treat anxiety/depression.

[04] Studying Naked Mole Rats

1. Why are Abdus-Saboor and his team studying naked mole rats?

• Naked mole rats rely heavily on touch, with a brain area devoted to touch that is three times larger than in other mammals.
• They also do not feel pain from capsaicin (the active ingredient in hot peppers), suggesting they have brain pathways that shut down pain signals.
• Studying these pain-insensitive pathways in mole rats could lead to new ways to block pain in humans.

2. What challenges has Abdus-Saboor faced as a young Black scientist?

• He has been fortunate to have supportive mentors and colleagues of diverse backgrounds, unlike some other underrepresented minorities.
• However, he has still experienced incidents of racism, such as being stopped and harassed by university police who did not think he belonged on campus.
• His advice to aspiring Black scientists is to surround themselves with good people, be open to support from unexpected sources, and not let these challenges crush their dreams.