表達(dá)各種不同神經(jīng)傳輸物質(zhì)的神經(jīng)元之間的平衡,，被認(rèn)為是在腦發(fā)育過程中由基因控制確定的。這是一個(gè)關(guān)鍵的步驟,，它使得各組神經(jīng)元之間能夠傳遞信號?，F(xiàn)在，由Davide Dulcis 和 Nicholas Spitzer完成的一項(xiàng)新的研究表明,，生理刺激也能調(diào)控一組神經(jīng)元中所表達(dá)的神經(jīng)傳輸物質(zhì)類別,。
研究發(fā)現(xiàn)，暴露于自然光的蝌蚪會(huì)增加表達(dá)多巴胺的中樞神經(jīng)元的數(shù)量,，而這反過來又會(huì)影響皮膚顏色變化及它們的偽裝潛力,。本期封面所示為在自然環(huán)境中適應(yīng)了黑暗的一只蝌蚪和適應(yīng)了光照的一只蝌蚪，其中一只比另一只偽裝更好,。這一發(fā)現(xiàn)也許還有更廣泛的意義,，并且還可能與由生源胺調(diào)控的認(rèn)知狀態(tài)的變化有關(guān)。有趣的是,，人們用亮光療法治療季節(jié)性情感障礙患者已有20多年了,。季節(jié)性情感障礙是一種抑郁癥，被發(fā)現(xiàn)與多巴胺信號作用障礙有關(guān),。（生物谷Bioon.com）
生物谷推薦原始出處：
Nature 456, 195-201 (13 November 2008) | doi:10.1038/nature07569
Illumination controls differentiation of dopamine neurons regulating behaviour
Davide Dulcis1 & Nicholas C. Spitzer
Neurobiology Section, Division of Biological Sciences and Center for Molecular Genetics, Kavli Institute for Brain and Mind, UCSD La Jolla, California 92093-0357, USA
Abstract
Specification of the appropriate neurotransmitter is a crucial step in neuronal differentiation because it enables signalling among populations of neurons. Experimental manipulations demonstrate that both autonomous and activity-dependent genetic programs contribute to this process during development, but whether natural environmental stimuli specify transmitter expression in a neuronal population is unknown. We investigated neurons of the ventral suprachiasmatic nucleus that regulate neuroendocrine pituitary function in response to light in teleosts, amphibia and primates. Here we show that altering light exposure, which changes the sensory input to the circuit controlling adaptation of skin pigmentation to background, changes the number of neurons expressing dopamine in larvae of the amphibian Xenopus laevis in a circuit-specific and activity-dependent manner. Neurons newly expressing dopamine then regulate changes in camouflage colouration in response to illumination. Thus, physiological activity alters the numbers of behaviourally relevant amine-transmitter-expressing neurons in the brain at postembryonic stages of development. The results may be pertinent to changes in cognitive states that are regulated by biogenic amines.
