Pinna Edge Biopsy of 7 and 21 Day Old C57BL/6 Mice as a Method for Identification and Genotyping.

Identifying and genotyping mice prior to weaning can be useful for mouse colony management. Mice of an undesired genotype can be identified prior to weaning and removed from further study, resulting in a reduction of housing costs, and labor time. We hypothesized that a pinna edge biopsy (PEB) performed by removing a portion of its edge with scissors is a reliable method for identifying and genotyping mice on postnatal day (PND) 7 consistent with PND 21, weaned mice. The pinnae of 54 C57BL/NCrl6 mice were biopsied on PND 7, and another 54 were biopsied on PND 21. Nine pinna patterns were tested. The accuracy of pattern identification was assessed on PND 7, 14, 21, 30, and 63. The mean times were compared for performing the biopsy on PND 7 and PND 21 mice, and the average time taken to identify the patterns were determined. Weight, milk spot presence, pup rejection, morbidity, and mortality were examined at various time points. During the biopsy, bleeding of the pinna, urination, vocalization, and flinching were assessed. No significant differences were detected in DNA quality, relative DNA quantity, genotyping reliability, or body weight (P ≥ 0.05) between mice biopsied on PND 7 and PND 21. Flinching at the time of PEB was significantly higher in PND 21 mice as compared with PND 7 mice (P < 0.00001). Pinna pattern identification accuracy for mice biopsied on PND 7 and PND 21 were 96% and 98%, respectively. This study validates the use of PEB for simultaneous identification and genotyping of PND 7 mice.

Evaluation and Refinement of a Spot-change-only Cage Management System for Mice.

Maximizing operational efficiency while maintaining appropriate animal housing conditions is a continuous focus of research animal care programs. Our institution's longstanding approach to cage-change management included scheduled cage changes every 2 wk, with spot changes if cages met established visual criteria during the intervening period. This 2-wk plus spot changing (2WS) practice for mice housed in IVC was problematic during the COVID-19 pandemic when the need arose to minimize workload to reduce on-site staffing out of concern for employee health and possible absenteeism. With the approval of the IACUC, a spot-change-only (SCO) process was adopted, with the requirement to evaluate microenvironmental parameters under both practices to confirm acceptable equivalence. These parameters (humidity, temperature, and ammonia) were evaluated in a controlled study that found no significant difference between the 2 groups. Ammonia levels did not exceed 10 ppm in any group throughout the study. To assess operational differences between these 2 approaches, we collected cage-change data and employee feedback from facilities operating under these schemes. The SCO method required fewer cage changes than did the 2WS method (10.3% per day with 2WS and 8.4% per day with SCO). Despite this benefit, through a Plan-Do-Check-Act process that has been regularly employed at our institution, employee feedback identified important operational challenges associated with the SCO practice. The SCO approach was thus refined into a scheduled spot change (SSC) practice that builds on the SCO model by incorporating a scheduled focused cage evaluation period. Based on subsequent feedback, the SSC was found to retain the efficiency benefits afforded by the SCO model and simultaneously alleviated staff and operational concerns. This result underscores the importance of integrating staff feedback with a performance standard-based approach when assessing cage-change management.

Patterns of brain activation when mothers view their own child and dog: an fMRI study.

Neural substrates underlying the human-pet relationship are largely unknown. We examined fMRI brain activation patterns as mothers viewed images of their own child and dog and an unfamiliar child and dog. There was a common network of brain regions involved in emotion, reward, affiliation, visual processing and social cognition when mothers viewed images of both their child and dog. Viewing images of their child resulted in brain activity in the midbrain (ventral tegmental area/substantia nigra involved in reward/affiliation), while a more posterior cortical brain activation pattern involving fusiform gyrus (visual processing of faces and social cognition) characterized a mother's response to her dog. Mothers also rated images of their child and dog as eliciting similar levels of excitement (arousal) and pleasantness (valence), although the difference in the own vs. unfamiliar child comparison was larger than the own vs. unfamiliar dog comparison for arousal. Valence ratings of their dog were also positively correlated with ratings of the attachment to their dog. Although there are similarities in the perceived emotional experience and brain function associated with the mother-child and mother-dog bond, there are also key differences that may reflect variance in the evolutionary course and function of these relationships.

Mainstreaming animal-assisted therapy.

The term animal-assisted therapy (AAT) commonly refers to the presentation of an animal to one or more persons for the purpose of providing a beneficial impact on human health or well-being. AAT is an ideal example of "One Health" because of numerous studies and widespread testimonials indicating that many humans feel better in the presence of pets and other domesticated animals, and, conversely, that some of those creatures appear to respond positively to human company for their emotional and perhaps physical betterment. Many AAT studies have claimed a wide range of human health benefits, but much of the research is characterized by small-scale interventions among disparate fields, resulting in criticisms about weak study design or inconsistent methodology. Such criticisms contrast with the strongly held belief among many that interaction with friendly animals has a strong and innate value for the persons involved. Consequently the appeal of AAT in human medicine today may be generally characterized as a "push" by enthusiastic advocates rather than a "pull" by prescribing physicians. To fully integrate AAT into conventional medical practice as an accepted therapeutic modality, more convincing intervention studies are necessary to confirm its clinical merits, along with an understanding of the underlying mechanism of the human response to the company of friendly animals.