Kinoshita Masae, Ito Etsuro
Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan.
Prog Neurobiol. 2006 Jun;79(2):112-21. doi: 10.1016/j.pneurobio.2006.06.002. Epub 2006 Aug 9.
The midbrain roof is a retinorecipient region referred to as the optic tectum in lower vertebrates, and the superior colliculus in mammals. The retinal fibers projecting to the tectum transmit visual information to tectal retinorecipient neurons. Periventricular neurons are a subtype of these neurons that have their somata in the deepest layer of the teleostean tectum and apical dendrites ramifying at more superficial layers consisting of retinal fibers. The retinotectal synapses between the retinal fibers and periventricular neurons are glutamatergic, and ionotropic glutamate receptors mediate the transmission in these synapses. This transmission involves long-term potentiation, and is modulated by hormone action. Visual information processed in the periventricular neurons is transmitted to adjacent tectal cells and target nuclei of periventricular neuron axonal branches, some of which relay the visual information to other brain areas controlling behavior. We demonstrated that periventricular neurons play a principal role in visual information processing in the teleostean optic tectum; the effects of tectal output on behavior is discussed also in the present review.
中脑顶盖是一个接受视网膜投射的区域，在低等脊椎动物中称为视顶盖，在哺乳动物中称为上丘。投射到顶盖的视网膜纤维将视觉信息传递给顶盖接受视网膜投射的神经元。室周神经元是这些神经元的一个亚型，其胞体位于硬骨鱼顶盖的最深层，顶端树突在由视网膜纤维组成的较浅层分支。视网膜纤维与室周神经元之间的视网膜顶盖突触是谷氨酸能的，离子型谷氨酸受体介导这些突触中的传递。这种传递涉及长时程增强，并受激素作用调节。在室周神经元中处理的视觉信息被传递到相邻的顶盖细胞和室周神经元轴突分支的靶核，其中一些将视觉信息传递到控制行为的其他脑区。我们证明室周神经元在硬骨鱼视顶盖的视觉信息处理中起主要作用；本综述还讨论了顶盖输出对行为的影响。
