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
Constellation of studies charts brain development, offers ‘dramatic revision’
The atlases could pinpoint pathways that determine the fate of cells linked to neurodevelopmental conditions.
Constellation of studies charts brain development, offers ‘dramatic revision’
By
Holly Barker
5 November 2025 | 6 min read
Protein tug-of-war controls pace of synaptic development, sets human brains apart
Human-specific duplicates of SRGAP2 prolong cortical development by manipulating SYNGAP, an autism-linked protein that slows synaptic growth.
Protein tug-of-war controls pace of synaptic development, sets human brains apart
By
Holly Barker
23 October 2025 | 7 min read
Worms help untangle brain structure/function mystery
The synaptic connectome of most animals bears little resemblance to functional brain maps, but it can still predict neuronal activity, according to two preprints that tackle the puzzle in C. elegans.
Worms help untangle brain structure/function mystery
By
Holly Barker
29 August 2025 | 7 min read
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
By
Holly Barker
8 August 2025 | 7 min read
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.
Explore more from The Transmitter
Genetic profiles separate early, late autism diagnoses
Age at diagnosis reflects underlying differences in common genetic variants and developmental trajectories among people with autism.
Genetic profiles separate early, late autism diagnoses
Age at diagnosis reflects underlying differences in common genetic variants and developmental trajectories among people with autism.
By
Natalia Mesa
27 November 2025 | 5 min read
To persist, memories surf molecular waves from thalamus to cortex
During the later stages of learning, the mouse brain progressively activates transcriptional regulators that drive memory consolidation.
To persist, memories surf molecular waves from thalamus to cortex
During the later stages of learning, the mouse brain progressively activates transcriptional regulators that drive memory consolidation.
By
Claudia López Lloreda
26 November 2025 | 4 min read
Sex hormone boosts female rats’ sensitivity to unexpected rewards
During the high-estradiol stages of their estrus cycle, female rats learn faster than they do during other stages—and than male rats overall—thanks to a boost in their dopaminergic response to reward, a new study suggests.
Sex hormone boosts female rats’ sensitivity to unexpected rewards
During the high-estradiol stages of their estrus cycle, female rats learn faster than they do during other stages—and than male rats overall—thanks to a boost in their dopaminergic response to reward, a new study suggests.
By
Angie Voyles Askham
26 November 2025 | 5 min read