據(jù)美國(guó)物理學(xué)家組織網(wǎng)10月25日?qǐng)?bào)道,，英國(guó)布里斯托爾大學(xué)神經(jīng)科學(xué)家最新研究發(fā)現(xiàn)，大麻成分會(huì)造成注意力不集中和記憶混亂,，使腦部活動(dòng)變得協(xié)調(diào)脫節(jié),，準(zhǔn)確性下降，神經(jīng)系統(tǒng)在生理和功能上均受到損害,，出現(xiàn)類(lèi)似精神分裂癥患者所看到的景象,。相關(guān)論文發(fā)表在10月25日出版的《神經(jīng)科學(xué)期刊》上。
大腦的活動(dòng)方式就像一個(gè)包含著弦樂(lè),、銅管樂(lè),、木管樂(lè)和打擊樂(lè)部分的交響樂(lè)團(tuán)，這些樂(lè)部按照指揮的節(jié)奏和諧連接,，編排組織在一起,。與此類(lèi)似，大腦也有著多種特殊結(jié)構(gòu),，能從一種頻率調(diào)到另一種確定的頻率,，這些有節(jié)率活動(dòng)產(chǎn)生了腦波，正常調(diào)整這些腦波,，就能處理各種信息以指導(dǎo)自身行為,。
該研究由布里斯托爾大學(xué)英國(guó)醫(yī)學(xué)研究理事會(huì)（MRC）非臨床成員、生理與藥理博士馬特·瓊斯領(lǐng)導(dǎo),。他們給一些小鼠服用了大麻中影響精神活動(dòng)的藥物成分,，然后用最先進(jìn)的技術(shù)檢測(cè)小鼠腦中數(shù)百個(gè)神經(jīng)元的電活動(dòng)。結(jié)果發(fā)現(xiàn),，藥物在個(gè)別腦區(qū)產(chǎn)生了微妙的效果,，跨越海馬回和前額葉皮質(zhì)區(qū)的腦波的協(xié)調(diào)性完全被打亂，好像這兩部分無(wú)法同步發(fā)揮作用,。而這些腦區(qū)對(duì)記憶和決策功能至關(guān)重要,，也和精神分裂病理學(xué)密切相關(guān)。由于海馬回和前額葉皮質(zhì)協(xié)調(diào)脫節(jié),，把小鼠放到一個(gè)迷宮里時(shí),，它們無(wú)法做出正確決策。
論文第一作者邁克爾·卡斯維茨說(shuō)：“這些發(fā)現(xiàn)有助于人們研究大腦怎樣有節(jié)奏地運(yùn)作,，以及健康大腦和疾病大腦思維過(guò)程的差別,。”
瓊斯表示：“這些發(fā)現(xiàn)對(duì)人們理解精神疾病有重要意義。為了治療精神分裂，濫用大麻很普遍,，我們的研究表明,，大麻藥物成分也會(huì)使健康人產(chǎn)生某些精神分裂癥狀，這可能是由于‘大腦解編’的結(jié)果,，可以通過(guò)重新調(diào)整腦活動(dòng)來(lái)治療。”（生物谷 Bioon.com）
doi:10.1523/JNEUROSCI.2970-11.2011
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Dysfunctional Prefrontal Cortical Network Activity and Interactions following Cannabinoid Receptor Activation
Michal T. Kucewicz1,2, Mark D. Tricklebank2, Rafal Bogacz3, and Matthew W. Jones1,2
Coordinated activity spanning anatomically distributed neuronal networks underpins cognition and mediates limbic–cortical interactions during learning, memory, and decision-making. We used CP55940, a potent agonist of brain cannabinoid receptors known to disrupt coordinated activity in hippocampus, to investigate the roles of network oscillations during hippocampal and medial prefrontal cortical (mPFC) interactions in rats. During quiet wakefulness and rest, CP55940 dose-dependently reduced 0.1–30 Hz local field potential power in CA1 of the hippocampus while concurrently decreasing 30–100 Hz power in mPFC; these contrasting population-level effects were paralleled by differential effects on underlying single-unit activity in the two structures. During decision-making phases of a spatial working memory task, CP5540-induced deficits in hippocampal theta and prefrontal gamma oscillations were observed alongside disrupted theta-frequency coherence between the two structures. These changes in coordinated limbic–cortical network activities correlated with (1) reduced accuracy of task performance, (2) impaired phase-locking of prefrontal single-unit spiking to the local gamma and hippocampal theta rhythms, and (3) impaired task-dependent activity in a subset of mPFC units. In addition to highlighting the importance of CA1–mPFC network oscillations for cognition, these results implicate disrupted theta-frequency coordination of CA1–mPFC activity in t
