Although neonatal altricial rodents are frequently used in experimental projects in which they must undergo survival surgical procedures, there are few published guidelines for anesthetizing them. Many of the drugs and methods that are commonly used to anesthetize newborn rodents provide inadequate anesthesia or are associated with problems, such as excessively high mortality. A two-part study was undertaken with the intention of identifying agents or methods that can be used to provide humane, safe, and effective anesthesia for neonatal rats. In part I, 1- to 3-day-old rat pups were anesthetized with methoxyflurane or one of several injectable agents, or by induction of hypothermia (immersion in ice water). Times to loss of the righting reflex, surgical anesthesia (indicated by loss of the pedal reflex and failure to respond to a skin incision), and recovery of the righting reflex were measured, and heart rate, respiratory rate, and oxygen saturation were monitored. Ketamine (100 mg/kg of body weight, i.p.), pentobarbital (30 to 40 mg/kg, i.p.), and fentanyl-droperidol combination (0.16 mg of fentanyl and 8.0 micrograms of droperidol/g, i.p.) proved unsafe (> 50% mortality) and/or ineffective at inducing short-term surgical anesthesia. In contrast, methoxyflurane and hypothermia were safe and effective. On the basis of subjective observations that they struggled and vocalized less, pups placed in protective latex sleeves prior to immersion in ice water appeared to be less distressed than pups immersed unprotected. In part II of the study, it was possible to safely maintain 1- to 3-day-old pups at a surgical plane of anesthesia for 30 min with either methoxyflurane or hypothermia. Supplementation with pentobarbital (20 mg/kg, i.p.) offered no advantages but significantly prolonged time to recovery. Surviving pups in both studies grew at similar rates during the month after testing. It was concluded that methoxyflurane or hypothermia are good choices for short- or long-term anesthesia of neonatal rats, and that use of a protective sleeve appears to reduce distress associated with induction of profound hypothermia.
Abstract null null Thyroid hormones (THs) are essential for foetal brain development. Because the gestating mother is the main source of THs to the foetus, maternal hypothyroidism and/or premature birth compromise neurological outcomes in the offspring. Respiratory instability and recurrent apneas due to immaturity of the respiratory control network are major causes of morbidity in infants. Inadequate TH supply may be sufficient to delay perinatal maturation of the respiratory control system; ho...
#1Young-A Lee(CUA: The Catholic University of America)H-Index: 7
#2Yu-Jeong Kim(CUA: The Catholic University of America)H-Index: 2
Last. Yukiori Goto(Primate Research Institute)H-Index: 18
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Abstract Alterations in dopamine (DA) and serotonin (5-HT) transmission have been implicated in the pathophysiology of attention deficit/hyperactivity disorder (ADHD). We have previously reported that juvenile rats with neonatal habenula lesion (NHL) exhibit an assortment of behavioral alterations resembling ADHD symptoms. In this study, we investigated the impacts of NHL on DA and 5-HT transmission in mesocorticolimbic regions of rats. Male Sprague-Dawley rats with microinjection of ibotenic ac...
There is an art and science to performing mouse anesthesia, which is a significant component to animal research. Frequently, anesthesia is one vital step of many over the course of a research project spanning weeks, months, or beyond. It is critical to perform anesthesia according to the approved research protocol using appropriately handled and administered pharmaceutical-grade compounds whenever possible. Sufficient documentation of the anesthetic event and procedure should also be performed t...
Last. Marat Minlebaev(Kazan: Kazan Federal University)H-Index: 18
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Functional studies in the central nervous system are often conducted using anesthesia. While the dose-dependent effects of anesthesia on neuronal activity have been extensively characterized in adults, little is known about the effects of anesthesia on cortical activity and cerebral blood flow in the immature central nervous system. Substitution of electrophysiological recordings with the less-invasive technique of optical intrinsic signal imaging (OIS) in vivo allowed simultaneous recordings of...
The study described a novel, rapidly performed, successful and safe surgical procedure in rats to achieve a reduction in the number of conceptuses. The objectives were to investigate the total foetal count and foetal health in both uterine horns after unilateral salpingectomy compared to the control group. Sixteen female Sprague-Dawley rats ( Rattus norvegicus ) were allocated to the study of which 10 rats underwent unilateral salpingectomy with six controls before all 16 were mated at 8–10 week...
Last. Keisuke Harada(Sapporo Medical University)H-Index: 3
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Whether central apnoea or hypopnoea can be induced by organophosphorus poisoning remains unknown to date. By using the acute brainstem slice method and multi-electrode array system, we established a paraoxon (a typical acetylcholinesterase inhibitor) poisoning model to investigate the time-dependent changes in respiratory burst amplitudes of the pre-Botzinger complex (respiratory rhythm generator). We then determined whether pralidoxime or atropine, which are antidotes of paraoxon, could counter...
Abstract The central adrenergic and noradrenergic neurotransmitter systems diffusively affect the operation of the spinal neural network and dynamically gauge central sympathetic outflow. Using in vitro splanchnic nerve–thoracic spinal cord preparations as an experimental model, this study examined the intraspinal α1-adrenoceptor-meidated modulation of sympathetic firing behaviors. Several sympathetic single-fiber activities were simultaneously recorded. Application of phenylephrine (Phe, an α1-...
The optimal choice of euthanasia method for laboratory rodents depends on a number of factors, including the scientific goals of the study, the need to minimize animal pain and/or distress, applicable guidelines and laws, the training and proficiency of personnel, and the safety and emotional needs of the personnel performing the euthanasia. This manuscript aims to provide guidance to researchers so they may select the method of euthanasia that results in minimal experimental confounds, such as ...
#1Camille Loiseau(French Institute of Health and Medical Research)H-Index: 3
#2Alexis Casciato(French Institute of Health and Medical Research)H-Index: 1
Last. Laurence Bodineau(French Institute of Health and Medical Research)H-Index: 12
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Dysfunction of central respiratory CO2/H+ chemosensitivity is a pivotal factor that elicits deep hypoventilation in patients suffering from central hypoventilation syndromes. No pharmacological treatment is currently available. The progestin desogestrel has been suggested to allow recovery of respiratory response to CO2/H+ in patients suffering from central hypoventilation, but except the fact that supramedullary regions may be involved, mechanisms are still unknown. Here, we tested in neonates ...
: The use of immature rodents to study physiologic aspects of cortical development requires high-quality recordings electroencephalography (EEG) with simultaneous video recording (vEEG) of behavior. Normative developmental vEEG data in control animals are fundamental for the study of abnormal background activity in animal models of seizures or other neurologic disorders. Electrical recordings from immature, freely behaving rodents can be particularly difficult because of the small size of immatu...
