Apoptotic neurodegeneration and spatial memory are not affected by sedative and anaesthetics doses of ketamine/medetomidine combinations in adult mice.
ABSTRACT Ketamine is increasingly popular in clinical practice and its combination with α(2)-agonists can provide good anaesthetic stability. Little is known about the effects of this combination in the brain. Therefore, we investigated the effects of different concentrations of ketamine combined with medetomidine on cognition and its potential apoptotic neurodegenerative effect in adult mice.
Seventy-eight C57BL/6 adult mice were divided into six different groups (saline solution, 1 mg kg(-1) medetomidine, 25 mg kg(-1) ketamine+1 mg kg(-1) medetomidine, 75 mg kg(-1) ketamine+1 mg kg(-1) medetomidine, 25 mg kg(-1) ketamine, and 75 mg kg(-1) ketamine). Eight animals per group were tested in the T-maze, vertical pole, and open-field test. Five animals per group were used for histopathological [haematoxylin and eosin (HE) staining] and immunohistochemical analyses [caspase-3 activation and expression of neurotrophin brain-derived neurotrophic factor (BDNF)]. Cells showing clear HE staining and positive immunoreactions for caspase-3 and BDNF in the retrosplenial cortex, visual cortex, pyramidal cell layer of the cornu Ammonis 1 and cornu Ammonis 3 areas of the hippocampus, and in the granular layer of the dentate gyrus were counted.
There were no differences between groups regarding the number of dead cells and cells showing positive immunoreactions in the different areas of the brain studied. Similarly, no differences were detected in the number of trials to complete the T-maze task. Nevertheless, α(2)-agonist decreased hyperlocomotion caused by ketamine in the open field.
Neither apoptotic neurodegeneration nor alterations in spatial memory were observed with different concentrations of ketamine combined with medetomidine in adult mice.
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ABSTRACT: We report the use of the alpha2 agonist, dexmedetomidine, with low-dose ketamine as a safe and effective treatment strategy to provide adequate comfort and sedation for a patient who fulfilled criteria of a difficult airway and required awake fibreoptic intubation (AFOI). A 52-yr-old male with prostate cancer presented for radical prostatectomy. He reported several failed intubations with previous surgeries and airway examination was consistent with a difficult intubation. In addition, previous fibreoptic intubations were unsuccessful. The patient reported extreme apprehension concerning his airway management. The goal of medicating patients for AFOI includes providing comfort and sedation without causing a change in ventilatory status. Dexmedetomidine has a high affinity for the alpha2 receptor and results in sedation without change in ventilatory status. In addition, dexmedetomidine is a potent anti-sialgogue which makes it desirable for cases involved with airway instrumentation. A loading dose of dexmedetomidine followed by a continuous infusion provided comfort and sedation within ten minutes. While bradycardia and hypotension have been reported with dexmedetomidine use, concurrent low-dose ketamine was employed in this case for it's cardiostimulatory properties and no bradycardia and hypotension were noted. The airway was anesthetized with selective nerve blocks and conditions for airway instrumentation were excellent. There was no change in oxygen saturation or ventilatory status during the administration of medications or airway manipulation. The patient was comfortable, sedated and tolerated the procedures well. There was no recall of the procedure. Dexmedetomidine and concurrent low-dose ketamine provided sedation and comfort to this patient who required an AFOI.Canadian Journal of Anaesthesia 01/2003; 50(6):607-10. · 2.13 Impact Factor
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ABSTRACT: Treatment with non-competitive N-methyl-D-aspartate (NMDA) antagonists such as phencyclidine or ketamine have been shown to induce schizophrenia-like psychotic and cognitive symptoms in humans and animals. However, there have been a number of contradictory findings regarding the effects of repeated treatment with these drugs on working memory in experimental animals. We hypothesized that processes dependent on dopamine transmission in the medial prefrontal cortex (PFC) may be more sensitive to disruption following these treatment. We assessed the effects of repeated treatment with ketamine on working memory performance using a delayed spatial win-shift procedure conducted on a radial-arm maze, dependent on a neural circuit linking hippocampal and dopamine inputs to the medial PFC. Rats were trained on the task prior to drug exposure, after which they were subjected to one of two dosing regimes of ketamine (30 mg/kg twice a day for either 5 or 10 days). After a 10 day withdrawal period, they were re-tested on the task for 15 days. Ketamine treatment for 10 days, but not 5 days, increased the number of errors and days to re-achieve the criterion on the delayed task. However, in a separate group of rats, subchronic ketamine treatment (10 days) did not affect performance of the non-delayed random foraging task, dependent on the hippocampus, but not the PFC. These results indicate that working memory performance assessed with these procedures is sensitive to disruption following repeated exposure to ketamine. Impairments in working memory induced by these treatments are not attributable to dysfunction of motivational, motor, short-term or spatial memory processes. The use of these procedures may prove useful in modeling impairments in this executive function observed in schizophrenia.Progress in Neuro-Psychopharmacology and Biological Psychiatry 04/2009; 33(4):668-75. · 3.55 Impact Factor
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ABSTRACT: The article presents the first experience with the use of steroid anesthetic drug Ketalar in patients with severe mechanical trauma and traumatic shock at the prehospital stage. The technique employed and its influence upon some indices of the patient's state are described. The positive effect of Ketalar upon hemodynamics of patients with a critical trauma is noted. The advantages of this anesthesia over the drugs used earlier at the prehospital stage are stressed. A conclusion is made concerning the expediency of a wider use of Ketalar in the practical work of resuscitation teams of the emergency medical service.Vestnik khirurgii imeni I. I. Grekova 08/1984; 132(7):88-91.