Lambe Evelyn K, Olausson Peter, Horst Nicole K, Taylor Jane R, Aghajanian George K
Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut 06508, USA.
J Neurosci. 2005 May 25;25(21):5225-9. doi: 10.1523/JNEUROSCI.0719-05.2005.
Thalamic projections to prefrontal cortex are important for executive aspects of attention. Using two-photon imaging in prefrontal brain slices, we show that nicotine and the wakefulness neuropeptide hypocretin (orexin) excite the same identified synapses of the thalamocortical arousal pathway within the prefrontal cortex. Although it is known that attention can be improved when nicotine is infused directly into the midlayer of the prefrontal cortex in the rat, the effects of hypocretin on attention are not known. The overlap in thalamocortical synapses excited by hypocretin and nicotine and the lack of direct postsynaptic effects prompted us to compare their effects on a sustained and divided attention task in the rat. Similar to nicotine, infusions of hypocretin-2 peptide into the prefrontal cortex significantly improved accuracy under high attentional demand without effects on other performance measures. We show for the first time that hypocretin can improve attentional processes relevant to executive functions of the prefrontal cortex.
丘脑向前额叶皮质的投射对于注意力的执行方面很重要。利用前额叶脑片的双光子成像技术，我们发现尼古丁和促觉醒神经肽下丘脑分泌素（食欲素）能兴奋前额叶皮质内丘脑皮质觉醒通路中相同的已确定突触。虽然已知将尼古丁直接注入大鼠前额叶皮质中层时注意力可得到改善，但下丘脑分泌素对注意力的影响尚不清楚。下丘脑分泌素和尼古丁所兴奋的丘脑皮质突触存在重叠，且不存在直接的突触后效应，这促使我们比较它们对大鼠持续和分散注意力任务的影响。与尼古丁类似，将下丘脑分泌素 -2 肽注入前额叶皮质在高注意力需求下显著提高了准确性，而对其他行为指标没有影响。我们首次表明，下丘脑分泌素可以改善与前额叶皮质执行功能相关的注意力过程。
