Biology subjects

Morrow, E.

Publications and source records attributed to Morrow, E..

3 recordsLinked to original sources

bioRxiv2025

Cat brains age like humans: Translating Time shows pet cats live to be natural models for human aging

Translating biological time across species is a powerful tool to identify new models of human aging and disease. Currently, it is not clear whether any animal reaches an age comparable to a human in their 80s. Most species seem to age differently compared with humans. Some preliminary observations suggest that cats may share common patterns of aging with humans. Cats could serve as a promising model for human aging. Here, we find corresponding ages between cats, humans and other species to test whether cats can live to the equivalent of a human in their 80s. We analyzed 3,754 observations across species from sudden and gradual changes in anatomy, physiology, and behavior. Some of these data are from clinical records, whereas others are from brain scans using high-resolution MRI (7T and 3T). We studied pet cats, research colony cats, and wildcats living in zoos to encapsulate species variation in the speed of development and aging. We found that cat and human brains atrophy with age, and that their age-related patterns in brain aging are sufficiently similar that we could use them to generate cross-species age alignments. We also found that human postnatal development is stretched compared with cats and mice. Interestingly, some pet cats that visit clinics are much older than those in colonies. Therefore, cats, and especially pet cats, are natural model systems of human aging. Our findings call for increased integration across veterinary and human medicine to understand aging.

neuroscience↗

bioRxiv2025

Dopaminergic processes predict temporal distortions in event memory

Our memories do not simply keep time -- they warp it, bending the past to fit the structure of our experiences. For example, people tend to remember items as occurring farther apart in time if they spanned a change in context, or event boundary, compared to the same context. While these distortions could sacrifice precise timing, they might also serve to divide and organize information into distinct memories. In the current study, we combined functional magnetic resonance imaging (fMRI; n = 32) with eye-tracking (n = 28) to test whether activation of the dopaminergic system, known to influence encoding and time perception, predicts time dilation between adjacent events in memory. Participants encoded item sequences while listening to tones that mostly repeated over time, forming a stable auditory context, but occasionally switched, creating an event boundary. We found that boundaries predicted greater retrospective estimates of time between item pairs. Critically, tone switches significantly activated the ventral tegmental area (VTA), a key midbrain dopaminergic region, and these responses predicted greater time dilation between item pairs that spanned those switches. Boundaries furthermore predicted a momentary increase in blinks. Activation of the VTA predicted blinking in general, consistent with the idea that blink behavior is a potential marker of dopaminergic activity. On a larger timescale, higher blink counts predicted greater time dilation in memory, but only for boundary-spanning item pairs. Together, these findings suggest that dopaminergic processes are sensitive to event structure and may drive temporal distortions that help to separate memories of distinct events.

neuroscience↗

bioRxiv2018

A molecular phylogeny of bedbugs elucidates the evolution of host associations and sex-reversal of reproductive trait diversification

All 100+ bedbug species (Cimicidae) are obligate blood-sucking parasites and well-known for their habit of traumatic insemination but the evolutionary trajectory of these characters is unknown. Our new, fossil-dated, molecular phylogeny estimates that ancestral Cimicidae evolved ca. 115MYA as hematophagous specialists on an unidentified host, 50MY before bats, switching to bats and birds thereafter. Humans were independently colonized three times and our phylogeny rejects the idea that the divergence of the two current urban pests (Cimex lectularius and C. hemipterus) 47MYA was associated with the divergence of Homo sapiens and H. erectus (1.6MYA). The females functional reproductive tract is unusually diverse and heterotopic, despite the unusual and strong morphological stasis of the male genitalia. This sex-reversal in genital co-variation is incompatible with current models of genital evolution. The evolutionary trait diversification in cimicids allowed us to uncover fascinating biology and link it to human pre-history and current activity.

ecology↗