TY - JOUR
T1 - Acepromazine and Chlorpromazine as Pharmaceutical-grade Alternatives to Chlorprothixene for Pupillary Light Reflex Imaging in Mice
AU - Eckley, Samantha S.
AU - Villano, Jason S.
AU - Kuo, Nora S.
AU - Wong, Kwoon Y.
N1 - Funding Information:
Support for this study was provided by the University of Michigan Animal Care and Use Program Quality Improvement Funds and by NIH National Eye Institute grants R01 EY023660 and P30 EY007003. We thank Dr Jean Nemzek (Unit for Laboratory Animal Medicine, University of Michigan) for the use of her PhysioSuite monitoring device and Dr Zachary Freeman (Unit for Laboratory Animal Medicine, University of Michigan) for assistance with statistical analysis.
Publisher Copyright:
© 2020 American Association for Laboratory Animal Science. All rights reserved.
PY - 2020/3
Y1 - 2020/3
N2 - Studies of visual responses in isoflurane-Anesthetized mice often use the sedative chlorprothixene to decrease the amount of isoflurane used because excessive isoflurane could adversely affect light-evoked responses. However, data are not available to justify the use of this nonpharmaceutical-grade chemical. The current study tested whether pharmaceutical-grade sedatives would be appropriate alternatives for imaging pupillary light reflexes. Male 15-wk-old mice were injected intraperitoneally with 1 mg/kg chlorprothixene, 5 mg/kg acepromazine, 10 mg/kg chlorpromazine, or saline. After anesthetic induction, anesthesia maintenance used 0.5% and 1% isoflurane for sedative-and saline-injected mice, respectively. A photostimulus (16.0 log photons cm-2 s-1; 470 nm) was presented to the right eye for 20 min, during which the left eye was imaged for consensual pupillary constriction and involuntary pupil drift. Time to immobilization, loss of righting reflex, physiologic parameters, gain of righting reflex, and degree of recovery were assessed also. The sedative groups were statistically indistinguishable for all measures. By contrast, pupillary drift occurred far more often in saline-Treated mice than in the sedative groups. Furthermore, saline-Treated mice took longer to reach maximal pupil constriction than all sedative groups and had lower heart rates compared with chlorpromazine-and chlorprothixene-sedated mice. Full recovery (as defined by purposeful movement, response to tactile stimuli, and full alertness) was not regularly achieved in any sedative group. In conclusion, at the doses tested, acepromazine and chlorpromazine are suitable pharmaceutical-grade alternatives to chlorprothixene for pupil imaging and conceivably other in vivo photoresponse measurements; however, given the lack of full recovery, lower dosages should be investigated further for use in survival procedures.
AB - Studies of visual responses in isoflurane-Anesthetized mice often use the sedative chlorprothixene to decrease the amount of isoflurane used because excessive isoflurane could adversely affect light-evoked responses. However, data are not available to justify the use of this nonpharmaceutical-grade chemical. The current study tested whether pharmaceutical-grade sedatives would be appropriate alternatives for imaging pupillary light reflexes. Male 15-wk-old mice were injected intraperitoneally with 1 mg/kg chlorprothixene, 5 mg/kg acepromazine, 10 mg/kg chlorpromazine, or saline. After anesthetic induction, anesthesia maintenance used 0.5% and 1% isoflurane for sedative-and saline-injected mice, respectively. A photostimulus (16.0 log photons cm-2 s-1; 470 nm) was presented to the right eye for 20 min, during which the left eye was imaged for consensual pupillary constriction and involuntary pupil drift. Time to immobilization, loss of righting reflex, physiologic parameters, gain of righting reflex, and degree of recovery were assessed also. The sedative groups were statistically indistinguishable for all measures. By contrast, pupillary drift occurred far more often in saline-Treated mice than in the sedative groups. Furthermore, saline-Treated mice took longer to reach maximal pupil constriction than all sedative groups and had lower heart rates compared with chlorpromazine-and chlorprothixene-sedated mice. Full recovery (as defined by purposeful movement, response to tactile stimuli, and full alertness) was not regularly achieved in any sedative group. In conclusion, at the doses tested, acepromazine and chlorpromazine are suitable pharmaceutical-grade alternatives to chlorprothixene for pupil imaging and conceivably other in vivo photoresponse measurements; however, given the lack of full recovery, lower dosages should be investigated further for use in survival procedures.
KW - GORR
KW - LORR
KW - PLR
KW - gain of righting reflex
KW - loss of righting reflex
KW - pupillary light reflex
UR - http://www.scopus.com/inward/record.url?scp=85081946106&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85081946106&partnerID=8YFLogxK
U2 - 10.30802/AALAS-JAALAS-19-000094
DO - 10.30802/AALAS-JAALAS-19-000094
M3 - Article
C2 - 31915106
AN - SCOPUS:85081946106
SN - 1559-6109
VL - 59
SP - 197
EP - 203
JO - Journal of the American Association for Laboratory Animal Science
JF - Journal of the American Association for Laboratory Animal Science
IS - 2
ER -