Navigation Links
Stimulation of brain region restores consciousness to animals under general anesthesia
Date:7/28/2014

Stimulating one of two dopamine-producing regions in the brain was able to arouse animals receiving general anesthesia with either isoflurane or propofol. In the August issue of Anesthesiology, investigators from Massachusetts General Hospital (MGH) report that rats anesthetized with continuous doses of either agent would move, raise their heads and even stand up in response to electrical stimulation delivered to the ventral tegmental area (VTA). Stimulation of the other major dopamine-releasing area, the substantia nigra, did not induce the animals to wake up.

"Dopamine cells in the VTA are involved in cognition, motivation and reward, while cells in the substantia nigra are important for movement; and our results showed that VTA cells may also be involved in dopamine's known arousal function." explains Ken Solt, MD, of the MGH Department of Anesthesia, Critical Care and Pain Medicine, corresponding author of the report. "Clinically, emergence from general anesthesia is still a passive process during which we just wait for the drugs to wear off and the patient to wake up, a process that can take from a few minutes to an hour or longer. Finding a way to safely arouse patients from anesthesia could both improve operating room efficiency and, even more importantly, may reduce problems such as postoperative delirium and cognitive dysfunction."

Previous studies by Solt and his colleagues have shown that administration of the stimulant drug methylphenidate (Ritalin), known to enhance dopamine-mediated neurotransmission, aroused animals receiving general anesthesia with either inhaled isoflurane or intravenous propofol. An additional study found that activating dopamine receptors also induced reanimation in anesthetized animals, but since older evidence implied that dopamine had no significant role in maintaining wakefulness, the MGH team designed the current study to investigate more directly the role of the brain's major dopamine-releasing structures in emergence from anesthesia.

Tiny electrodes were placed in either the VTA or the substantia nigra of anesthetized rats. Application of a mild electric current stimulates only the tissues directly adjacent to the electrodes, inducing dopamine release. Both groups of animals received continuous isoflurane anesthesia at a dose sufficient to maintain unconsciousness; but while electrical stimulation of the VTA successfully reanimated all animals in which electrodes were correctly positioned, stimulation of the substantia nigra produced no arousal response. Several days later the experiment was repeated using propofol in the animals that had reanimated with VTA stimulation, and again VTA stimulation restored conscious behaviors. A subsequent experiment showed that EEG recordings from anesthetized animals shifted to patterns associated with arousal in response to stimulation of the VTA but not to substantia nigra stimulation.

"These results suggest that the results of our methylphenidate studies were produced by increased dopamine release from the VTA," says Solt, an assistant professor of Ansthesia at Harvard Medical School. "Now we need to investigate the specific role of dopamine neurons and whether activating those cells could help prevent or treat postoperative problems."


'/>"/>

Contact: Terri Ogan
togan@partners.org
617-726-0954
Massachusetts General Hospital
Source:Eurekalert

Related medicine news :

1. Low strength brain stimulation may be effective for depression
2. Deep brain stimulation improves non motor symptoms in Parkinsons disease
3. Tendon stimulation the key to repair in tennis elbow
4. Rice researcher rebooting deep brain stimulation
5. What is being said in the media and academic literature about neurostimulation?
6. Deep brain stimulation for obsessive-compulsive disorder releases dopamine in the brain
7. Precise brain mapping can improve response to deep brain stimulation in depression
8. Functional electrical stimulation improves neuronal regeneration after cerebral infarction
9. New stroke research combines brain stimulation, gait training
10. Knellinger Dental Excellence Brings Laser Gum Disease Treatment for Bone Stimulation and Possible Tooth Loss Prevention
11. Parkinsons disease patients following subthalamic nucleus deep brain stimulation: fully understanding of social maladjustment
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/27/2016)... ... , ... TherapySites, the leading website and online ... Counseling Association. This new relationship allows TherapySites to continue to extend their ... benefits and promotional offers. , "TCA is extremely excited about this new partnership, ...
(Date:6/27/2016)... ... June 27, 2016 , ... A ... revolutionize the emergency ambulance transport experience for the millions of people who require ... has disrupted the taxi industry through the use of technology. Now, SmartEMS has ...
(Date:6/26/2016)... ... ... Quality metrics are proliferating in cancer care, and are derived from many of ... beholder, according to experts who offered insights and commentary in the current issue of ... full issue, click here . , For the American Society of Clinical Oncology ...
(Date:6/26/2016)... ... June 26, 2016 , ... Pixel Film Studios Released ProSlice Levels, ... editors can give their videos a whole new perspective by using the title ... Pixel Film Studios. , ProSlice Levels contains over 30 Different presets to choose ...
(Date:6/26/2016)... ... ... blind and certified personal trainer is helping to develop a weight loss fitness plan that ... the two major problems leading the fitness industry today:, , All ... They don’t eliminate all the reasons people quit their exercise program , ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... Bracket , a leading clinical trial technology ... outcomes platform, Bracket eCOA (SM) 6.0, at the 52 ... 30, 2016 in Philadelphia , Pennsylvania.  A ... product of its kind to fully integrate with RTSM, will ... 6.0 is a flexible platform for electronic clinical outcomes assessments ...
(Date:6/23/2016)... Colombia , June 23, 2016  Astellas today announced the establishment of Astellas Farma Colombia (AFC), a new ... affiliate in Latin America . ... ... ... ...
(Date:6/23/2016)... June 23, 2016 The vast majority of ... dialysis facility.  Treatments are usually 3 times a week, ... visit, including travel time, equipment preparation and wait time. ... especially grueling for patients who are elderly and frail.  ... nursing and rehabilitation centers for some duration of time. ...
Breaking Medicine Technology: