Biology subjects

Saenz, M.

Publications and source records attributed to Saenz, M..

3 recordsLinked to original sources

bioRxiv2025

Metabolic Cage Analysis of Surgically Catheterized C57Bl/6J Mice (Mus musculus) Treated with Carprofen and Sustained-release Buprenorphine

Federal regulations require that appropriate analgesia be provided for laboratory animals for pain control. Carprofen and buprenorphine are two common analgesics used for laboratory mice (Mus musculus). However, given the potential gastrointestinal side effects that these analgesics have in various species, the impact of these analgesics on mice used in metabolic studies could be concerning. To investigate the impact of carprofen and sustained-release buprenorphine on food consumption, activity level, and whole-body metabolism, we administered carprofen alone or in combination with sustained-release buprenorphine to mice that underwent jugular vein and carotid artery catheterization, or a sham surgery. The mice were individually housed in instrumented metabolic cages to continuously quantify food consumption, activity levels, and energy expenditure by indirect calorimetry. We hypothesized that catheterized mice receiving both carprofen and sustained-release buprenorphine would have decreased food consumption and increased activity level compared to mice that received sham surgery and carprofen, and catheterized mice treated with carprofen only would have similar food consumption and activity level as sham mice that received carprofen. Our results demonstrate that during the initial 12h after surgery, catheterized mice that received both carprofen and sustained-release buprenorphine were more active than sham mice that received carprofen, and were more active and consumed more food than catheterized mice that received carprofen only. Our study demonstrated how analgesia regimen can affect metabolic parameters. Therefore, researchers should carefully consider the effects that analgesic drugs can have on mice when designing metabolic or behavioral experiments.

animal behavior and cognition↗

bioRxiv2025

Memory Inception through Gaze-Contingent Message Exposure: Using Virtual Reality to Study Media Influence

The messages we encounter in our environment can shape our knowledge about the world. However, much research on mediadriven influence via messages focuses on population-level effects and aggregate exposure statistics, obscuring how individual and self-determined behaviors affect message intake, processing, and effects. To address this gap, we use virtual reality (VR) to create a controlled messaging environment. Participants navigate a simulated urban street lined with billboard messages while their visual attention is tracked via eye-tracking. We introduce an inception-style manipulation: overlooked billboards are strategically reintroduced, creating additional exposure opportunities. Our results demonstrate that this subtle manipulation - unnoticed by participants - boosts message retention. This study bridges communication theory and psychology, elucidating the blurred line between voluntary and involuntary information intake in the digital age. It also highlights a potential vulnerability in the future metaverse media ecosystem, where undetected information manipulations can influence individual and collective attention and memories.

animal behavior and cognition↗

bioRxiv2022

Pharmacokinetics of Sustained-Release Buprenorphine and Extended-Release Buprenorphine in Mice with Surgical Catheterization

The Guide for the Care and Use of Laboratory Animals strongly encourages the use of pharmaceutical grade chemicals and analgesics. The extra-label use of sustained-release buprenorphine (SRB) is commonly administered to rodents to mitigate moderate-to-severe pain. An FDA-indexed buprenorphine formulation, known as extended-release buprenorphine (XRB), has recently become available and is currently the only pharmaceutical grade slow-release buprenorphine approved for use in mice and rats. However, no studies have directly compared the pharmacokinetic (PK) parameters and therapeutic efficacy of SRB and XRB in surgically catheterized mice. Thus, we compared the plasma buprenorphine concentrations and PK parameters of SRB and XRB in mice after surgical catheterization. We hypothesized that mice treated with SRB or XRB would have circulating buprenorphine concentrations exceeding the therapeutic threshold for up to 72-hours post-operatively. Male and female C57Bl/6J mice were anesthetized, treated with either SRB (1 mg/kg, SC, once) or XRB (3.25 mg/kg, SC, once) and underwent surgical catheterization. At 6, 24, 48, and 72 h after SRB or XRB administration, arterial blood samples were collected. Post-operative weight loss was similar between groups with a decline of 11.7 {+/-} 1.6 and 12.3 {+/-} 0.7% in males and 7.6 {+/-} 2.2 and 8.1 {+/-} 1.1% (mean {+/-} SEM) in females treated with SRB and XRB, respectively. Both SRB and XRB maintained circulating buprenorphine concentrations above the therapeutic level of 1.0 ng/mL for 72 h after administration. XRB buprenorphine concentrations were significantly greater (3-4-fold) than SRB concentrations at 6, 24, and 48 h, commensurate with the increase dose concentration of XRB to SRB. These results support the use of either SRB or XRB for the alleviation of postoperative pain in mice. The new availability of FDA-indexed XRB increases the options for safe and effective pharmaceutical grade analgesia in rodents.

pharmacology and toxicology↗