New research suggests that the popular online advice to “touch grass” for emotional well-being might have scientific merit, at least when tested on laboratory mice.

**Outdoor-dwelling mice exhibit lower anxiety levels compared to their counterparts confined to laboratory enclosures, a finding that may expose a critical limitation in animal research, including studies assessing the safety and efficacy of human medications.**

Here are a few paraphrased options, each with a slightly different emphasis, while maintaining a journalistic tone:

**Option 1 (Focus on the disconnect):**

> The leap from promising laboratory results in mice to effective treatments for human patients is often fraught with disappointment, with some researchers suggesting that the highly artificial and solitary conditions of lab life for rodents may be a significant contributing factor to this translational gap.

**Option 2 (More direct and concise):**

> Many drugs that prove effective in laboratory mice ultimately fail to translate into successful human treatments, a phenomenon some scientists attribute, at least in part, to the unnatural and isolated existence laboratory rodents endure.

**Option 3 (Emphasizing the “why”):**

> A curious disconnect exists between drugs that show efficacy in lab mice and their performance in human trials. A growing number of scientists posit that the unusual and often solitary environment of laboratory life for these animals could be a key reason for this failure.

**Option 4 (Slightly more evocative):**

> The stark reality is that medications effective in controlled lab environments with mice frequently fall short when tested in humans. This discrepancy, some scientists contend, may be partly explained by the peculiar and isolated nature of laboratory life for these research subjects.

**Key changes made across these options:**

* **”Seem to work” replaced with stronger phrasing:** “promising laboratory results,” “prove effective,” “show efficacy,” “effective in controlled lab environments.”
* **”Don’t necessarily work” replaced with more definitive language:** “often fraught with disappointment,” “ultimately fail to translate,” “frequently fall short.”
* **”In part, because of” rephrased:** “a significant contributing factor to this translational gap,” “at least in part, to,” “could be a key reason for,” “may be partly explained by.”
* **”Bizarre and isolated laboratory life” reworded:** “highly artificial and solitary conditions,” “unnatural and isolated existence,” “unusual and often solitary environment,” “peculiar and isolated nature.”
* **Sentence structure varied:** Combining clauses, reordering elements for flow and impact.
* **Journalistic tone maintained:** Objective, factual, and clear language.

Here are a few paraphrased options, each with a slightly different journalistic emphasis:

**Option 1 (Focus on the Question):**

> A significant disconnect exists between how promising drug candidates perform in laboratory animal studies and their actual effectiveness in human trials. Matthew Zipple, lead author of a new study and a postdoctoral researcher at Cornell University, highlights this puzzling discrepancy, suggesting that the “highly artificial, standardized environment” in which lab animals are housed may be a key contributing factor.

**Option 2 (Focus on the Potential Cause):**

> The artificiality of laboratory animal environments may be a major reason why drug trial results often fail to translate from animal models to human patients. According to Matthew Zipple, the study’s first author and a postdoctoral researcher at Cornell University, the “really artificial, standardized environment” where these animals are kept could explain the “huge gap in results” observed when new drugs are tested in humans.

**Option 3 (More Direct and Concise):**

> Researchers are grappling with a substantial difference in drug efficacy between laboratory animal models and human trials. Matthew Zipple, a postdoctoral researcher at Cornell University and the study’s lead author, proposes that the highly controlled and unnatural conditions under which lab animals are housed could be a primary driver of this wide performance gap.

**Option 4 (Emphasizing the “Why”):**

> Why do drugs that show remarkable success in lab animals so often fall short in human clinical trials? Matthew Zipple, the first author of a recent study and a postdoctoral researcher at Cornell University, points to the possibility that the “really artificial, standardized environment” of animal research facilities plays a crucial role in this observable discrepancy.

In December, researchers unveiled their discoveries in the pages of the scientific journal *Current Biology*.

Here are a few paraphrased options, maintaining a journalistic tone:

**Option 1 (Focus on similarity and activity):**

> Much like humans, wild mice navigate complex social landscapes and lead highly active lives. Their days are a continuous cycle of foraging, excavating burrows, and evading a constant array of predators eager for a meal.

**Option 2 (Emphasis on the dynamic nature of their lives):**

> The lives of wild mice are characterized by bustling social interactions and perpetual motion. These creatures are always in pursuit of food, digging intricate homes, and living under the perpetual threat of numerous predators.

**Option 3 (More concise and direct):**

> Wild mice, similar to humans, exist within intricate social structures and lead dynamic lives. They are constantly engaged in foraging, burrowing, and a daily struggle for survival against a diverse range of predatory threats.

**Key changes made and why:**

* **”Rich social environments”** was rephrased to “complex social landscapes,” “bustling social interactions,” or “intricate social structures” to sound more descriptive and less cliché.
* **”Constantly on the go”** was replaced with more active and descriptive phrases like “highly active lives,” “perpetual motion,” or “constantly engaged.”
* **”Foraging, burrowing and facing risks, including the many predators that like to snack on them”** was broken down and reworded to sound more professional and less informal. Phrases like “evading a constant array of predators,” “perpetual threat of numerous predators,” and “daily struggle for survival against a diverse range of predatory threats” were used.
* **”Like to snack on them”** was replaced with more clinical and factual terms like “eager for a meal,” “predatory threats,” or “predators.”
* **Added transition words and phrases** like “Much like humans,” “Their days are a continuous cycle,” and “These creatures are always” to improve flow and readability.

Here are a few paraphrased options, each with a slightly different emphasis, while maintaining the journalistic tone:

**Option 1 (Focus on the contrast and analogy):**

> In stark contrast to their wild counterparts, laboratory mice are typically housed in cramped cages, often with only two or three same-sex cage mates. Their access to food and water is strictly controlled and provided on a set timetable. This confined existence, according to researcher Zipple speaking to Live Science, makes studying medications in these mice comparable to conducting research solely on individuals kept in solitary confinement.

**Option 2 (More direct and concise):**

> Unlike their natural environment, laboratory mice are confined to small cages, usually with a few same-sex siblings, and receive food and water on a regimented schedule. Zipple explained to Live Science that the implications of studying medications on these mice are akin to limiting research to prisoners in solitary confinement.

**Option 3 (Emphasizing the artificiality of the environment):**

> The artificial environment of a typical laboratory mouse cage, where a few same-sex siblings share limited space and receive food and water on a predictable schedule, presents a significant limitation. As Zipple shared with Live Science, investigating the effects of medications on mice in such conditions could be likened to studying treatments on prisoners who are held in solitary confinement.

**Option 4 (Slightly more evocative):**

> Confined to small cages with a handful of same-sex companions, and with food and water dispensed on a fixed schedule, the reality for lab mice is a far cry from their natural habitat. Zipple told Live Science that the practice of studying medications in such controlled settings may be as revealing as researching treatments on individuals subjected to solitary confinement.

**Key changes made in these paraphrases:**

* **Word Choice:** Replaced words like “sit in,” “delivered,” and “akin to” with more descriptive or varied vocabulary (e.g., “housed in,” “provided,” “comparable to,” “likened to,” “revealing as”).
* **Sentence Structure:** Varied the sentence beginnings and combined or separated clauses to create a more dynamic flow.
* **Emphasis:** Shifted the focus slightly in each option to highlight different aspects of the original statement.
* **Journalistic Tone:** Maintained a factual, objective, and informative style.
* **Attribution:** Clearly attributed the quote to Zipple and the publication to Live Science.

Researchers led by Zipple conducted a study to investigate the psychological differences between two distinct groups of laboratory mice. One group was housed in a traditional laboratory setting, while the other was relocated to an outdoor enclosure. This outdoor environment was designed to mimic natural conditions, featuring grass, soil, and direct exposure to the sky. To assess their psychological states, Zipple and his team employed a common experimental tool known as the “elevated plus maze.” This apparatus consists of four arms: two that are covered and provide a sense of security, and two that are open and resemble narrow walkways.

In a standard laboratory setup, mice, when first introduced to an illuminated maze, exhibit a predictable behavioral pattern. They tend to cautiously explore the maze’s open pathways, but their initial forays are met with apprehension. Consequently, these mice overwhelmingly retreat to the more secure, enclosed sections of the maze, rarely venturing back into the exposed areas. This consistent response is so reliable that scientists utilize the open arms of the maze as a method for both provoking and quantifying anxiety levels in these rodents.

Researchers observed that mice in a naturalistic setting showed no apprehension towards the open arms of a maze. According to Zipple and his colleagues, these mice continued to explore these brightly lit areas with the same level of curiosity on subsequent trials as they had on their initial foray, indicating a lack of fear or stress.

Mice housed in cages and then moved to an outdoor environment experienced a significant reduction in their anxiety within mazes. Specifically, those mice that had previously shown a reluctance to venture into open spaces subsequently spent double the amount of time exploring these areas after just one week outdoors, in contrast to their counterparts who remained in their familiar caged settings.

According to Andrea Graham, an evolutionary ecologist at Princeton University who was not involved in the study, the standardized maze served as a “very powerful way to show the limits of business as usual.”

Researchers at Graham’s lab have observed a significant distinction in the immune systems of mice housed in sterile laboratory cages compared to their wild counterparts. This divergence is attributed to the latter’s exposure to a more complex environment, including soil, plant matter, and a larger population of fellow mice. This difference, according to Graham, carries important implications.

A 2006 clinical trial for a drug named TGN1412 took a dramatic turn when a substance that showed promise in combating leukemia in lab mice resulted in a life-threatening immune overreaction in the initial group of healthy human participants.

Investigations following the incident uncovered a critical difference in how the drug interacted with the immune systems of different animal models. In laboratory mice, TGN1412 appeared to stimulate immune cells designed to manage and temper the body’s defenses. However, when administered to mice in more natural, wild-type environments, the drug triggered a different set of immune cells. These cells amplified the immune response so intensely that the body began to attack its own tissues.

Graham explained to Live Science that focusing research exclusively on a restricted number of lab mouse genetic profiles, housed in overly sterile and unchallenging environments, severely impedes the study of the full breadth of human immune and nervous system reactions to their surroundings.

Implementing naturalistic enclosures for research animals carries a significant initial price tag in both cost and effort, a departure from traditional lab settings. These “wild-style” environments inherently loosen the stringent controls typically placed on study subjects – controls vital for limiting confounding variables in experiments. This shift, according to Zipple, fundamentally challenges established biomedical research practices, pushing scientists well outside their conventional comfort zones.

The study’s authors contend that incorporating tests with less-confined mice could yield significant efficiencies and cost savings in human clinical trials. This approach, they argue, would be crucial for pinpointing medications with the highest likelihood of successful translation from laboratory settings to clinical application. In parallel research, lead investigator Zipple and his team are currently examining how the aging processes diverge between caged and wild-living mouse populations.

A pivotal research initiative seeks to compile a definitive inventory of biomedically relevant behaviors, observable traits, and psychological characteristics that demonstrate consistency across both controlled laboratory environments and real-world settings. This effort, according to a representative, is designed to significantly improve the translation of research findings to human health applications. Equally important, the project also plans to identify and document traits that exhibit considerable divergence when observed in these varying contexts.