Effect of the ketamine/xylazine anesthetic on the auditory brainstem response of adult gerbils

Abstract

The auditory brainstem response (ABR) is a test widely used to assess the integrity of the brain stem. Although it is considered to be an auditory-evoked potential that is influenced by the physical characteristics of the stimulus, such as rate, polarity and type of stimulus, it may also be influenced by the change in several parameters. The use of anesthetics may adversely influence the value of the ABR wave latency. One of the anesthetics used for ABR assessment, especially in animal research, is the ketamine/xylazine combination. Our objective was to determine the influence of the ketamine/xylazine anesthetic on the ABR latency values in adult gerbils. The ABRs of 12 adult gerbils injected with the anesthetic were collected on three consecutive days, or a total of six collections, namely: pre-collection and A, B, C, D, and E collections. Before each collection the gerbil was injected with a dose of ketamine (100 mg/kg)/xylazine (4 mg/kg). For the capture of the ABR, 2000 click stimuli were used with rarefaction polarity and 13 stimuli per second, 80 dBnHL intensity and in-ear phones. A statistically significant difference was observed in the latency of the V wave in the ABR of gerbils in the C and D collections compared to the pre-, A and E collections, and no difference was observed between the pre-, A, B, and E collections. We conclude that the use of ketamine/xylazine increases the latency of the V wave of the ABR after several doses injected into adult gerbils; thus, clinicians should consider the use of this substance in the assessment of ABR.

Brainstem Auditory Evoked Potentials in Raccoon Dogs (Nyctereutes procynoides)

“…1500 Hz) may be used eventually if the traces are not smooth enough for interpretation but anyway this was not the case in this study. In our case, the recordings were made under general anesthesia by using xylazine and ketamine, assuming that this method is as suitable as for dogs [20], cats [6] and gerbils [21]. Both xylazine and ketamine appears to have no effect over the registered BAER latency or waveform amplitudes registered [12].…”

Histological Structure of the Thyroid Gland in Apolipoprotein E Deficient Female Mice After Levothyroxine Application

“…Xylazine is an agonist of alpha 2 adrenergic receptors located presynaptically. These receptors reduce noradrenaline release by inhibiting the influx of calcium in the neuron, with a consequent hypotensive and tranquilizing effect [17]. In one study it has been observed that the ketamine/xylazine combination markedly suppresses cardiac function, characterized by reductions in heart rate [18].…”

Utility of the auditory brainstem response evaluation in non-clinical drug safety evaluations

“…Drugs such as isoflurane that are commonly used to produce sedation can differentially affect the function of the central nervous system, resulting in increased auditory thresholds (Ruebhausen, Brozoski, & Bauer, 2012). Due to these complications, ketamine and xylazine (or other α-2 adrenergicagonists) are routinely used for ABR evaluations and have been shown to produce accurate minimum thresholds (Lima, Ariga, Velasco, & Schochat, 2012;Smith & Mills, 1989). The types of anesthetics used for ABR evaluations can also produce significant decreases in body temperature (Bill, Hughes, & Stephens, 1989).…”