alejandra manjarrez

Alejandra Manjarrez, PhD

Alejandra Manjarrez is a freelance science journalist who contributes to The Scientist. She has a PhD in systems biology from ETH Zurich and a master’s in molecular biology from Utrecht University. After years studying bacteria in a lab, she now spends most of her days reading, writing, and hunting science stories, either while traveling or visiting random libraries around the world. Her work has also appeared in Hakai, The Atlantic, and Lab Times.

Articles by Alejandra Manjarrez, PhD
Brain cell in purple on a black background. Arc mRNAs are labeled green and are mainly localized in the cell nucleus and in the dendrites.
Short-lived Molecules Support Long-term Memory 
Alejandra Manjarrez, PhD | Jun 6, 2023 | 3 min read
A gene essential for information storage in the brain engages an autoregulatory feedback loop to consolidate memory.
Side and front view of a male human skull
Mechanical Force on the Skull May Aid Bone Regeneration
Alejandra Manjarrez, PhD | May 1, 2023 | 3 min read
By mechanically inducing the expansion of cranial sutures in young adult mice, researchers stimulated stem cell proliferation that is key to healing bone injuries.
Image of methylated DNA
Stress Increases Biological Age, But Recovery Can Revert It
Alejandra Manjarrez, PhD | Apr 21, 2023 | 2 min read
A new study relying on DNA methylation clocks suggests that the biological age of mouse and human cells can fluctuate in response to stressful events.
Bladder epithelial tissue, where cell junctions are shown in green and nuclei in blue. This was grown in vitro from cells taken from mice with chronic cystitis.
Bladder ‘Memory’ Influences Urinary Tract Infection Recurrence in Mice
Alejandra Manjarrez, PhD | Apr 12, 2023 | 3 min read
Urinary tract infections leave permanent epigenetic marks in the mouse bladder epithelium, reprogramming its response to subsequent infections, a study finds.
Image of the fly brain (grey) highlighting the population of neurons (pink) to which the gut-secreted peptide CCHa1 signals
A Protein-Rich Diet Helps Mice and Flies Sleep More Soundly: Study
Alejandra Manjarrez, PhD | Mar 24, 2023 | 3 min read
The effect appears to be mediated by a gut-secreted peptide that signals to neurons in the brain that modulate the response to mechanical vibrations.
Two pink-colored, rod-shaped bacteria interacting with a blue-colored human cell
Gut Bacterium Linked to Depression in Premenopause
Alejandra Manjarrez, PhD | Mar 17, 2023 | 2 min read
The opportunistic pathogen Klebsiella aerogenes degrades estradiol and induces depressive-like behavior in mice, a study finds.
A cross-section of mouse brain showing the locus coeruleus in fluorescent green
Hormone Sobers Up Drunken Mice: Study
Alejandra Manjarrez, PhD | Mar 8, 2023 | 3 min read
A hormone naturally induced by alcohol consumption accelerates the recovery of mice after binge drinking by activating neurons involved in arousal and alertness.
Nerve cell labelled with different colours
Psychedelics Slip Past Cell Membranes When Treating Depression
Alejandra Manjarrez, PhD | Feb 24, 2023 | 4 min read
The antidepressant properties of hallucinogenic drugs may stem from their ability to bind to intracellular serotonin receptors, a study suggests.
The face of a young woman and the face of an old man surrounded by mechanical clocks.
Daily Gene Expression Rhythms Vary with Sex and Age: Study
Alejandra Manjarrez, PhD | Feb 2, 2023 | 3 min read
By studying tissues from deceased people, a team found that women have more rhythmical gene expression and that this molecular rhythmicity decreases with age.
A younger-looking mouse next to an older-looking one
Epigenetic Manipulations Can Accelerate or Reverse Aging in Mice
Alejandra Manjarrez, PhD | Jan 12, 2023 | 4 min read
Repairing damaged DNA appears to drive aging by causing the loss of epigenetic information, but restoring that information reverses such effects, a study finds.