Wahle P, Stuphorn V, Schmidt M, Hoffmann K P
Lehrstuhl für Allgemeine Zoologie und Neurobiologie, Fakultät für Biologie, Ruhr-Universität Bochum, Germany.
Eur J Neurosci. 1994 Mar 1;6(3):454-60. doi: 10.1111/j.1460-9568.1994.tb00287.x.
There have been conflicting reports on the chemical nature of the projection of the pretectal nuclei [nucleus of the optic tract and dorsal terminal nucleus of the accessory optic tract (NOT-DTN complex) and posterior pretectal nucleus] to the lateral geniculate nucleus and inferior olive. There is evidence that the pretecto-geniculate pathway is inhibitory. However, most attempts to verify the GABAergic nature of the projection neurons have failed. In order to answer this question, we employed a combination of retrograde transport and in situ hybridization. Rhodamine-labelled latex microspheres were injected into the electrophysiologically identified lateral geniculate nucleus. In addition, fluorescein-labelled latex microspheres were injected into the inferior olive. Retrograde axonal transport labelled large pretectal neurons. We then applied riboprobes specific for glutamic acid decarboxylase mRNA. We were able to demonstrate glutamic acid decarboxylase mRNA expression in up to 70% of lateral geniculate nucleus-projecting NOT-DTN and posterior pretectal nucleus neurons but in none of the pretecto-olivary projection neurons. The results suggest that the pretecto-geniculate projection is GABAergic in nature, which would confirm previous electrophysiological and morphological observations. The pretecto-olivary projection is not GABAergic.
关于顶盖前核[视束核与副视束背侧终核（NOT-DTN复合体）及顶盖前核后部]向外侧膝状体核和下橄榄核投射的化学性质，一直存在相互矛盾的报道。有证据表明顶盖前-膝状体通路具有抑制性。然而，大多数验证投射神经元GABA能性质的尝试均未成功。为了回答这个问题，我们采用了逆行运输和原位杂交相结合的方法。将罗丹明标记的乳胶微球注入经电生理鉴定的外侧膝状体核。此外，将荧光素标记的乳胶微球注入下橄榄核。逆行轴突运输标记了顶盖前的大神经元。然后我们应用针对谷氨酸脱羧酶mRNA的核糖探针。我们能够证明，在向外侧膝状体核投射的NOT-DTN和顶盖前核后部神经元中，高达70%的神经元表达谷氨酸脱羧酶mRNA，但在顶盖前-橄榄核投射神经元中均未检测到。结果表明，顶盖前-膝状体投射本质上是GABA能的，这将证实先前的电生理和形态学观察结果。顶盖前-橄榄核投射不是GABA能的。
