Holly Barker is a freelance writer specializing in biology, medicine and psychology. She has a Ph.D. in clinical neuroscience from King’s College London in the United Kingdom and a B.Sc. degree in biochemistry from the University of Manchester. She has previously written for Discover and BioNews. She is based in London.

Holly Barker
Contributing writer
From this contributor
Oxytocin prompts prairie voles to oust outsiders, fortifying their friendships
The “love hormone” drives the neurobiology behind platonic bonds in animals usually studied for their romantic attachments.

Oxytocin prompts prairie voles to oust outsiders, fortifying their friendships
Genetic background steers PTEN syndrome traits
People with the syndrome, caused by variants in the gene PTEN, often have autism or cancer, or both, but it depends on the genetic diversity encoded in the components of distinct cell signaling pathways, according to a new study.
Some dopamine neurons signal default behaviors to reinforce habits
Movement-sensing neurons that target the striatum influence a mouse’s choice of action by favoring routine.

Some dopamine neurons signal default behaviors to reinforce habits
Split gene therapy delivers promise in mice modeling Dravet syndrome
The new approach overcomes viral packaging limitations by delivering SCN1A piecemeal and stitching it together in target cells.

Split gene therapy delivers promise in mice modeling Dravet syndrome
PTEN problems underscore autism connection to excess brain fluid
Damaging variants in the autism-linked gene cause congenital hydrocephalus—a buildup of cerebrospinal fluid in the brain—by turbocharging a downstream signaling pathway that promotes the growth of cells, according to a new study.

PTEN problems underscore autism connection to excess brain fluid
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Microglia nurture young interneurons
The immune cells secrete a growth factor that “sets the supply of GABAergic interneurons in the developing brain.”

Microglia nurture young interneurons
The immune cells secrete a growth factor that “sets the supply of GABAergic interneurons in the developing brain.”
Xaq Pitkow shares his principles for studying cognition in our imperfect brains and bodies
Pitkow discusses how evolution's messy constraints shape optimal brain algorithms, from Bayesian inference to ecological affordances.
Xaq Pitkow shares his principles for studying cognition in our imperfect brains and bodies
Pitkow discusses how evolution's messy constraints shape optimal brain algorithms, from Bayesian inference to ecological affordances.
The Transmitter’s reading list: Six upcoming neuroscience books, plus notable titles in 2025
Dig into an exploration of the fundamental aspects of intelligence, a new textbook about theoretical neuroscience and a memoir about memory research, among other new releases.

The Transmitter’s reading list: Six upcoming neuroscience books, plus notable titles in 2025
Dig into an exploration of the fundamental aspects of intelligence, a new textbook about theoretical neuroscience and a memoir about memory research, among other new releases.