Histamine H3 receptor and orexin A expression during daily torpor in the Djungarian hamster (Phodopus sungorus)
Histamine H3 receptor and orexin A expression during daily torpor in the Djungarian hamster (Phodopus sungorus)
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DOI：
10.1111/j.1365-2826.2007.01620.x
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发表时间：
2007-12-01
影响因子：
3.2
通讯作者：
Loudon, A. S.
中科院分区：
文献类型：
--
作者：
Herwig, A.;Ivanova, E. A.;Loudon, A. S.
季节性动物使用不同的策略来减少能量消耗，以减少季节性食物供应。例如，地松鼠进入冬眠状态，新陈代谢减少，体温降低，中枢神经系统活动受到抑制，而Djungarian仓鼠（Phodopus sungorus）每天都会出现与体温降低和能量消耗相关的麻痹。对冬眠地松鼠的研究表明，脑中组胺合成和组胺H-3受体表达的增加是控制冬眠的一种中枢机制。在本研究中，我们证明了一个上调的H-3受体在几个脑核中的Djungarian仓鼠在发作的日常麻木，浅形式的体温过低，这表明组胺能通路可能发挥一般作用，在维持低体温和麻木状态的哺乳动物。这些区域包括弓状核、下丘脑背内侧核、视交叉上核、外侧膝状体背侧核和结节乳核。有趣的是，食欲素（一组增加觉醒的神经肽）的mRNA表达在日常麻木的唤醒过程中保持不变，这表明这种经典的“唤醒”途径并不参与从低体温到正常体温状态的转变。
Seasonal animals use different strategies to reduce energy expenditure in the face of reduced seasonal food availability. For example, the ground squirrel enters a hibernation state with reduced metabolism, hypothermia and suppressed central nervous system activity, whereas the Djungarian hamster (Phodopus sungorus) employs daily bouts of torpor associated with reduced body temperature and energy expenditure. Studies in the hibernating ground squirrel implicate an increase in histamine synthesis and histamine H-3 receptor expression in the brain as a central mechanism governing hibernation. In the present study, we demonstrate an up-regulation of H-3 receptors in several brain nuclei in the Djungarian hamster during bouts of daily torpor, a shallow form of hypothermia, suggesting that histaminergic pathways may play a general role in maintaining low body temperature and torpor state in mammals. These regions include the arcuate nucleus, dorsomedial hypothalamus, suprachiasmatic nucleus, dorsal lateral geniculate nucleus and tuberomammilary nucleus. Interestingly, expression of the mRNA for orexins, a group of neuropeptides that increase wakefulness, remains unchanged during the arousal from daily torpor, suggesting that this classic 'arousal' pathway is not involved in the transition from a hypothermic to the euthermic state.