Background

Novel imaging technology and procedures were developed to study brain function in preadolescent awake marmosets never exposed to anesthesia.

Methods

A radiofrequency transmit and receive, head only volume coil was designed and integrated into a holding system. An acclimation procedure was developed without the use of anesthesia or sedation that allowed for awake imaging. Preadolescent 8-month old male and female marmosets were imaged for resting state BOLD functional connectivity to assess the status of the default mode network. Levels of reactivity during acclimation sessions and behavioral stress following imaging were assessed.

Results

Data on functional coupling in the default mode network suggest the organization of connectivity to the prefrontal cortex is not fully developed at 8 months of age. The stress associated with the imaging procedure is comparable to that observed when marmosets are removed from their home cage and temporarily isolated from the family.

Comparison to other methods

The design of the radiofrequency coil provides B1 homogeneity across the entire brain without signal drop off. The unique design of the head cradle obviates the need for any stabilizing surgery, ear bars or bite bar and could be adapted to any size marmoset. The acclimation requires no anesthesia or sedation at any time in the early life of the developing marmoset, a condition that better reflects the human experience.

Conclusion

A method is provided for imaging functional activity in the brain of fully awake preadolescent marmosets without any history of anesthesia or sedation.

中文翻译：

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研究青春期前清醒狨猴脑功能的新型成像技术和程序。

背景

开发了新的成像技术和程序来研究从未接触过麻醉的青春期前清醒狨猴的大脑功能。

方法

设计了射频发射和接收，仅头部体积线圈并集成到保持系统中。在不使用麻醉或镇静的情况下开发了适应程序，允许清醒成像。对青春期前 8 个月大的雄性和雌性狨猴进行静息状态 BOLD 功能连接的成像，以评估默认模式网络的状态。评估了适应过程中的反应水平和成像后的行为压力。

结果

默认模式网络中功能耦合的数据表明，与前额叶皮层的连接组织在 8 个月大时尚未完全发育。与成像过程相关的压力与将狨猴从其家笼中取出并暂时与家庭隔离时观察到的压力相当。

与其他方法的比较

射频线圈的设计在整个大脑中提供 B1 均匀性，而不会出现信号下降。头部支架的独特设计避免了任何稳定手术、耳棒或咬合棒的需要，并且可以适应任何大小的狨猴。在发育中的狨猴早期的任何时候，驯化都不需要麻醉或镇静，这种情况更能反映人类的经验。

结论

提供了一种用于对完全清醒的青春期前狨猴大脑中的功能活动进行成像的方法，没有任何麻醉或镇静史。