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Xu JX, Coker A, Dulaney Z, Furbish A, Xu FZ, Helke KL, Woster PM, Nietert PJ, Braxton AM. Establishing New Isosexual Pairs in Adult Male Guinea Pigs ( Cavia porcellus) to Facilitate Social Housing. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE : JAALAS 2024; 63:160-171. [PMID: 38262624 PMCID: PMC11022948 DOI: 10.30802/aalas-jaalas-23-000086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 10/06/2023] [Accepted: 01/03/2024] [Indexed: 01/25/2024]
Abstract
Guinea pigs (Cavia porcellus) are a commonly used species in biomedical research. As social creatures, compatible guinea pigs should be housed together unless scientific objectives or veterinary care require otherwise. Extensive literature suggests that adult male guinea pigs are highly aggressive in the presence of females, but data are lacking regarding the compatibility of cohoused adult males in the absence of females. Most studies that use adult males do not report housing densities. We used serial wound scoring and observations of behavior to determine whether unfamiliar adult male guinea pigs will develop stable, prosocial isosexual pairs. Wound scoring was performed before and 24 h after pairing. Serial behavioral observations assessed affiliative and agonistic behaviors at 0.5, 2, 24, and 48 h after pairing. Wound scoring and behavioral observations continued weekly for 1 mo and monthly thereafter. Wound scores were significantly higher at 24 h after pairing as compared with baseline and all other time points. Wounding was rare after week 2, indicating reduced aggression. Furthermore, affiliative behaviors significantly increased over time while agonistic behaviors were rare. Together, these data suggest that unfamiliar adult male guinea pigs establish stable prosocial pairs after an acclimation period. As was done in the present study, providing ample space, separate shelters for each animal, and the absence of female guinea pigs will likely facilitate successful pairing. We recommend consideration of a social housing program for adult male guinea pigs to provide companionship and enrich their housing environment.
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Affiliation(s)
- Jen X Xu
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina
| | - Ashton Coker
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina
| | - Zadie Dulaney
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina
| | - Amelia Furbish
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina
| | - Frank Z Xu
- Department of Biomedical Science, The University of Alabama at Birmingham, Birmingham, Alabama
| | - Kristi L Helke
- Department of Comparative Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Patrick M Woster
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina
| | - Paul J Nietert
- Department of Public Health Sciences, Medical University of South Carolina, Charleston, South Carolina
| | - Alicia M Braxton
- Department of Comparative Medicine, Medical University of South Carolina, Charleston, South Carolina;,
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Hotta R, Rahman A, Bhave S, Stavely R, Pan W, Srinivasan S, de Couto G, Rodriguez-Borlado L, Myers R, Burns AJ, Goldstein AM. Transplanted ENSCs form functional connections with intestinal smooth muscle and restore colonic motility in nNOS-deficient mice. Stem Cell Res Ther 2023; 14:232. [PMID: 37667277 PMCID: PMC10478362 DOI: 10.1186/s13287-023-03469-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 08/22/2023] [Indexed: 09/06/2023] Open
Abstract
BACKGROUND Enteric neuropathies, which result from abnormalities of the enteric nervous system, are associated with significant morbidity and high health-care costs, but current treatments are unsatisfactory. Cell-based therapy offers an innovative approach to replace the absent or abnormal enteric neurons and thereby restore gut function. METHODS Enteric neuronal stem cells (ENSCs) were isolated from the gastrointestinal tract of Wnt1-Cre;R26tdTomato mice and generated neurospheres (NS). NS transplants were performed via injection into the mid-colon mesenchyme of nNOS-/- mouse, a model of colonic dysmotility, using either 1 (n = 12) or 3 (n = 12) injections (30 NS per injection) targeted longitudinally 1-2 mm apart. Functional outcomes were assessed up to 6 weeks later using electromyography (EMG), electrical field stimulation (EFS), optogenetics, and by measuring colorectal motility. RESULTS Transplanted ENSCs formed nitrergic neurons in the nNOS-/- recipient colon. Multiple injections of ENSCs resulted in a significantly larger area of coverage compared to single injection alone and were associated with a marked improvement in colonic function, demonstrated by (1) increased colonic muscle activity by EMG recording, (2) faster rectal bead expulsion, and (3) increased fecal pellet output in vivo. Organ bath studies revealed direct neuromuscular communication by optogenetic stimulation of channelrhodopsin-expressing ENSCs and restoration of smooth muscle relaxation in response to EFS. CONCLUSIONS These results demonstrate that transplanted ENSCs can form effective neuromuscular connections and improve colonic motor function in a model of colonic dysmotility, and additionally reveal that multiple sites of cell delivery led to an improved response, paving the way for optimized clinical trial design.
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Affiliation(s)
- Ryo Hotta
- Department of Pediatric Surgery, Massachusetts General Hospital, Boston, MA, USA
| | - Ahmed Rahman
- Department of Pediatric Surgery, Massachusetts General Hospital, Boston, MA, USA
| | - Sukhada Bhave
- Department of Pediatric Surgery, Massachusetts General Hospital, Boston, MA, USA
| | - Rhian Stavely
- Department of Pediatric Surgery, Massachusetts General Hospital, Boston, MA, USA
| | - Weikang Pan
- Department of Pediatric Surgery, Massachusetts General Hospital, Boston, MA, USA
| | - Shriya Srinivasan
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Division of Gastroenterology, Hepatology and Endoscopy, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
- Society of Fellows, Harvard University, Cambridge, MA, USA
| | - Geoffrey de Couto
- Gastrointestinal Drug Discovery Unit, Takeda Development Center Americas, Inc., Cambridge, MA, USA
| | - Luis Rodriguez-Borlado
- Gastrointestinal Drug Discovery Unit, Takeda Development Center Americas, Inc., Cambridge, MA, USA
| | - Richard Myers
- Gastrointestinal Drug Discovery Unit, Takeda Development Center Americas, Inc., Cambridge, MA, USA
| | - Alan J Burns
- Gastrointestinal Drug Discovery Unit, Takeda Development Center Americas, Inc., Cambridge, MA, USA
- Stem Cells and Regenerative Medicine, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Allan M Goldstein
- Department of Pediatric Surgery, Massachusetts General Hospital, Boston, MA, USA.
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Hibberd TJ, Ramsay S, Spencer-Merris P, Dinning PG, Zagorodnyuk VP, Spencer NJ. Circadian rhythms in colonic function. Front Physiol 2023; 14:1239278. [PMID: 37711458 PMCID: PMC10498548 DOI: 10.3389/fphys.2023.1239278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 08/17/2023] [Indexed: 09/16/2023] Open
Abstract
A rhythmic expression of clock genes occurs within the cells of multiple organs and tissues throughout the body, termed "peripheral clocks." Peripheral clocks are subject to entrainment by a multitude of factors, many of which are directly or indirectly controlled by the light-entrainable clock located in the suprachiasmatic nucleus of the hypothalamus. Peripheral clocks occur in the gastrointestinal tract, notably the epithelia whose functions include regulation of absorption, permeability, and secretion of hormones; and in the myenteric plexus, which is the intrinsic neural network principally responsible for the coordination of muscular activity in the gut. This review focuses on the physiological circadian variation of major colonic functions and their entraining mechanisms, including colonic motility, absorption, hormone secretion, permeability, and pain signalling. Pathophysiological states such as irritable bowel syndrome and ulcerative colitis and their interactions with circadian rhythmicity are also described. Finally, the classic circadian hormone melatonin is discussed, which is expressed in the gut in greater quantities than the pineal gland, and whose exogenous use has been of therapeutic interest in treating colonic pathophysiological states, including those exacerbated by chronic circadian disruption.
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Affiliation(s)
- Timothy J. Hibberd
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | - Stewart Ramsay
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
| | | | - Phil G. Dinning
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
- Colorectal Surgical Unit, Division of Surgery, Flinders Medical Centre, Adelaide, SA, Australia
| | | | - Nick J. Spencer
- College of Medicine and Public Health, Flinders University, Adelaide, SA, Australia
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Smolilo DJ, Hibberd TJ, Costa M, Dinning PG, Keightley LJ, De Fontgalland D, Wattchow D, Spencer NJ. Stimulation of extrinsic sympathetic nerves differentially affects neurogenic motor activity in guinea pig distal colon. Physiol Rep 2023; 11:e15567. [PMID: 36636780 PMCID: PMC9837477 DOI: 10.14814/phy2.15567] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/25/2022] [Accepted: 12/26/2022] [Indexed: 06/17/2023] Open
Abstract
The speed of pellet propulsion through the isolated guinea pig distal colon in vitro significantly exceeds in vivo measurements, suggesting a role for inhibitory mechanisms from sources outside the gut. The aim of this study was to investigate the effects of sympathetic nerve stimulation on three different neurogenic motor behaviors of the distal colon: transient neural events (TNEs), colonic motor complexes (CMCs), and pellet propulsion. To do this, segments of guinea pig distal colon with intact connections to the inferior mesenteric ganglion (IMG) were set up in organ baths allowing for simultaneous extracellular suction electrode recordings from smooth muscle, video recordings for diameter mapping, and intraluminal manometry. Electrical stimulation (1-20 Hz) of colonic nerves surrounding the inferior mesenteric artery caused a statistically significant, frequency-dependent inhibition of TNEs, as well as single pellet propulsion, from frequencies of 5 Hz and greater. Significant inhibition of CMCs required stimulation frequencies of 10 Hz and greater. Phentolamine (3.6 μM) abolished effects of colonic nerve stimulation, consistent with a sympathetic noradrenergic mechanism. Sympathetic inhibition was constrained to regions with intact extrinsic nerve pathways, allowing normal motor behaviors to continue without modulation in adjacent extrinsically denervated regions of the same colonic segments. The results demonstrate differential sensitivities to sympathetic input among distinct neurogenic motor behaviors of the colon. Together with findings indicating CMCs activate colo-colonic sympathetic reflexes through the IMG, these results raise the possibility that CMCs may paradoxically facilitate suppression of pellet movement in vivo, through peripheral sympathetic reflex circuits.
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Affiliation(s)
- David J. Smolilo
- College of Medicine and Public HealthFlinders UniversityAdelaideSouth AustraliaAustralia
| | - Timothy J. Hibberd
- College of Medicine and Public HealthFlinders UniversityAdelaideSouth AustraliaAustralia
| | - Marcello Costa
- College of Medicine and Public HealthFlinders UniversityAdelaideSouth AustraliaAustralia
| | - Phil G. Dinning
- College of Medicine and Public HealthFlinders UniversityAdelaideSouth AustraliaAustralia
- Department of SurgeryFlinders Medical CentreBedford ParkSouth AustraliaAustralia
- Department of GastroenterologyFlinders Medical CentreBedford ParkSouth AustraliaAustralia
| | - Lauren J. Keightley
- College of Medicine and Public HealthFlinders UniversityAdelaideSouth AustraliaAustralia
| | - Dayan De Fontgalland
- Department of SurgeryFlinders Medical CentreBedford ParkSouth AustraliaAustralia
- Department of GastroenterologyFlinders Medical CentreBedford ParkSouth AustraliaAustralia
| | - David A. Wattchow
- Department of SurgeryFlinders Medical CentreBedford ParkSouth AustraliaAustralia
- Department of GastroenterologyFlinders Medical CentreBedford ParkSouth AustraliaAustralia
| | - Nick J. Spencer
- College of Medicine and Public HealthFlinders UniversityAdelaideSouth AustraliaAustralia
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Fu Q, Zhang Y, Chen L, Dong M, Tang W, Chen S, Qu J, Zhou X, Zhi Z. Near work induces myopia in Guinea pigs. Exp Eye Res 2022; 224:109202. [PMID: 35961425 DOI: 10.1016/j.exer.2022.109202] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 07/11/2022] [Accepted: 07/19/2022] [Indexed: 11/17/2022]
Abstract
The association between near work activities and myopia has not been clearly established. This study establishes a model for near work myopia (NWM) induced by short viewing distance in guinea pigs with a carefully controlled visual environment, and evaluates the effect of viewing distance in myopia development. Pigmented guinea pigs (3 weeks old) were randomly assigned to 3 groups: near work (NW)-, form-deprivation (FD)-, and -4D hyperopic-defocus (HD)-induced myopia. Animals in NW groups were kept in cylindrical cages with vertical square-wave gratings, providing short- (S, d = 18 cm), middle- (M, d = 44 cm), and long- (L, d = 88 cm) mean viewing distances, all at the same illuminance, during daily treatment for 14 days. Biometric parameters, including refraction, anterior chamber depth (ACD), lens thickness (LT), vitreous chamber depth (VCD), and axial length (AL), were measured at the beginning and end of 14 days' treatment. Choroidal thickness (ChT) and choroidal blood perfusion (ChBP) were measured by optical coherence tomography (OCT) and OCT-angiography (OCTA), respectively, at the end of treatment. Refraction was shifted towards myopia in the S-cage group, compared with the M- and L-cage groups; refractions in the L-, M- and S-cage groups were 5.19 ± 0.65 D, 4.30 ± 0.64 D, and 0.53 ± 0.61 D, respectively (p < 0.001). VCD and AL in the S-cage group increased in parallel with the myopic shift (L vs M vs S: VCD: 3.15 ± 0.02 mm vs 3.17 ± 0.02 mm vs 3.26 ± 0.02 mm, p < 0.001; AL: 7.99 ± 0.03 mm vs 8.03 ± 0.03 mm vs 8.15 ± 0.02 mm, p = 0.001). In FD and HD eyes, changes similar to those in the S-cage group (near-work group, NW) were seen in refraction (NW vs FD vs HD: 5.36 ± 0.82 D vs -5.78 ± 0.44 D vs -4.96 ± 0.54 D, p = 0.734), ACD, LT, VCD and AL. Also, ChT and ChBP were significantly less in the S-cage group than in the M- and L-cage groups after 14 days' treatment (L vs M vs S: ChT: 74.84 ± 3.27 vs 76.07 ± 3.49 vs 61.95 ± 3.31, P = 0.002; ChBP: 48.32 ± 2.23 vs 48.66 ± 2.30 vs 38.14 ± 2.06, p = 0.002). Rearing in S-cages induced myopia in guinea pigs and correspondingly decreased ChBP and ChT. The present study provides objective evidence that short viewing distance could be a risk factor for myopia, and describes a useful model for studying the underlying mechanisms.
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Affiliation(s)
- Qian Fu
- School of Optometry and Ophthalmology, and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, 325003, China; State Key Laboratory of Optometry, Ophthalmology, and Vision Science, Wenzhou, Zhejiang, 325003, China.
| | - Yue Zhang
- School of Optometry and Ophthalmology, and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, 325003, China; State Key Laboratory of Optometry, Ophthalmology, and Vision Science, Wenzhou, Zhejiang, 325003, China.
| | - Linji Chen
- School of Optometry and Ophthalmology, and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, 325003, China; State Key Laboratory of Optometry, Ophthalmology, and Vision Science, Wenzhou, Zhejiang, 325003, China.
| | - Mengmeng Dong
- School of Optometry and Ophthalmology, and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, 325003, China; State Key Laboratory of Optometry, Ophthalmology, and Vision Science, Wenzhou, Zhejiang, 325003, China.
| | - Wenyu Tang
- School of Optometry and Ophthalmology, and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, 325003, China; State Key Laboratory of Optometry, Ophthalmology, and Vision Science, Wenzhou, Zhejiang, 325003, China.
| | - Si Chen
- School of Optometry and Ophthalmology, and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, 325003, China; State Key Laboratory of Optometry, Ophthalmology, and Vision Science, Wenzhou, Zhejiang, 325003, China.
| | - Jia Qu
- School of Optometry and Ophthalmology, and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, 325003, China; State Key Laboratory of Optometry, Ophthalmology, and Vision Science, Wenzhou, Zhejiang, 325003, China; Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou, Zhejiang, 325038, China; Research Unit of Myopia Basic Research and Clinical Prevention and Control, Chinese Academy of Medical Sciences, Wenzhou, 325027, China.
| | - Xiangtian Zhou
- School of Optometry and Ophthalmology, and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, 325003, China; State Key Laboratory of Optometry, Ophthalmology, and Vision Science, Wenzhou, Zhejiang, 325003, China; Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou, Zhejiang, 325038, China; Research Unit of Myopia Basic Research and Clinical Prevention and Control, Chinese Academy of Medical Sciences, Wenzhou, 325027, China.
| | - Zhina Zhi
- School of Optometry and Ophthalmology, and Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, 325003, China; State Key Laboratory of Optometry, Ophthalmology, and Vision Science, Wenzhou, Zhejiang, 325003, China.
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Christie S, Zagorodnyuk V. Time-of-day dependent changes in guinea pig bladder afferent mechano-sensitivity. Sci Rep 2021; 11:19283. [PMID: 34588547 PMCID: PMC8481311 DOI: 10.1038/s41598-021-98831-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 09/08/2021] [Indexed: 01/03/2023] Open
Abstract
The voiding of urine has a clear circadian rhythm with increased voiding during active phases and decreased voiding during inactive phases. Bladder spinal afferents play a key role in the regulation of bladder storage and voiding, but it is unknown whether they exhibit themselves a potential circadian rhythm. Therefore, this study aimed to determine the mechano- and chemo- sensitivity of three major bladder afferent classes at two opposite day-night time points. Adult female guinea pigs underwent conscious voiding monitoring and bladder ex vivo single unit extracellular afferent recordings at 0300 h and 1500 h to determine day-night modulation of bladder afferent activity. All guinea pigs voided a higher amount of urine at 1500 h compared to 0300 h. This was due to an increased number of voids at 1500 h. The mechano-sensitivity of low- and high-threshold stretch-sensitive muscular-mucosal bladder afferents to mucosal stroking and stretch was significantly higher at 1500 h compared to 0300 h. Low-threshold stretch-insensitive mucosal afferent sensitivity to stroking was significantly higher at 1500 h compared to 0300 h. Further, the chemosensitivity of mucosal afferents to N-Oleoyl Dopamine (endogenous TRPV1 agonist) was also significantly increased at 1500 h compared to 0300 h. This data indicates that bladder afferents exhibit a significant time-of-day dependent variation in mechano-sensitivity which may influence urine voiding patterns. Further studies across a 24 h period are warranted to reveal potential circadian rhythm modulation of bladder afferent activity.
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Affiliation(s)
- Stewart Christie
- Discipline of Human Physiology, Flinders Health & Medical Research Institute, College of Medicine and Public Health, Flinders University, GPO Box 2100, Adelaide, SA, Australia
| | - Vladimir Zagorodnyuk
- Discipline of Human Physiology, Flinders Health & Medical Research Institute, College of Medicine and Public Health, Flinders University, GPO Box 2100, Adelaide, SA, Australia.
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