Spinothalamic and spinohypothalamic tract neurons in the sacral spinal cord of rats. I. Locations of antidromically identified axons in the cervical cord and diencephalon.
Spinothalamic and spinohypothalamic tract neurons in the sacral spinal cord of rats. I. Locations of antidromically identified axons in the cervical cord and diencephalon.
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大鼠骶脊髓中的脊髓丘脑和脊髓下丘脑束神经元。
DOI：
10.1152/jn.1996.75.6.2581
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
GieslerJr,GJ
中科院分区：
文献类型：
--
作者：
Katter,JT;Dado,RJ;Kostarczyk,E;GieslerJr,GJ
1. 本研究的目的是确定大鼠骶脊髓节段的神经元投射到间脑的哪个部位。因此，尿素脲麻醉大鼠L6-S2脊髓节段细胞外记录了95个神经元。在对侧后间脑放置一个单极刺激电极，当电流<或= 30微a时，这些神经元被反向激活。这些位点的平均正负电位激活电流为16 +/- 0.8 microA。这些神经元主要分布在背浅区（4%）、背深区（89%）、中间区和腹角区（4%）。2. 采用系统的反向映射技术绘制了间脑内41个这些神经元的轴突投影。当电流<或= 30微a时，33个神经元（80%）仅从对侧丘脑的点被反向激活，称为脊髓丘脑束（STT）神经元。8个神经元（20%）在低电流下从对侧丘脑和下丘脑的点被反向激活，这些神经元被称为脊髓丘脑束/脊髓下丘脑束（STT/SHT）神经元。另外三个神经元在电流<或= 30微a的情况下仅从对侧下丘脑内的点反向激活，称为脊髓-下丘脑束（SHT）神经元。另有51个神经元的间脑突起未完全绘制。这些神经元被称为脊髓丘脑/未知（STT/ U）神经元，表明尚不清楚它们的轴突是否上升到它们最初被反向激活的丘脑部位以外。3. 对于31个STT神经元，确定了电流<或= 30 microA时实现反向激活的最前方点。14个（45%）仅从丘脑腹底复合体（VbC）后方的位置反行激活。16个STT神经元（52%）在VbC水平的低电流下被反向激活，但在更前的水平上没有。一个STT神经元（3%）从丘脑前腹侧核反方向激活。4. STT/SHT神经元在电流<或= 30微a的情况下被反向激活，这些电流来自内侧小网膜（ML）、前前额核（APt）、后核群和内侧膝状核（Po/MG），以及丘脑的网状带和视束（OT）、视上讨论区或下丘脑外侧区。在丘脑中STT和STT/SHT神经元被反性激活的部位没有明显差异。5个STT/SHT神经元（62%）从间脑后部的丘脑点和更前水平的下丘脑点反方向激活。3个STT/SHT神经元（38%）在来自丘脑和下丘脑同一前后水平的电流<或= 30微a时被反向激活。这三个STT/SHT神经元都投射到丘脑的层内核（束旁核或中央外侧核）。5. 7个STT/SHT神经元被检测到同侧脑的额外投射。其中两个（29%）在电流<或= 30微a时被反向激活，并且在同侧间脑部位的潜伏期较长。一个只能从同侧下丘脑反方向激活。另一种是从同侧大脑的点以逐渐增加的潜伏期反方向激活的，这种点向后延伸到MG的后极。6. 58 STT, STT/SHT…
1. A goal of this study was to determine the sites in the diencephalon to which neurons in sacral spinal segments of rats project. Therefore, 95 neurons were recorded extracellularly in spinal segments L6-S2 of rats that were anesthetized with urethan. These neurons were activated initially antidromically with currents < or = 30 microA from a monopolar stimulating electrode placed into the contralateral posterior diencephalon. The mean +/- SE current for antidromic activation from these sites was 16 +/- 0.8 microA. These neurons were recorded in the superficial dorsal horn (4%), deep dorsal horn (89%), and intermediate zone and ventral horn (4%). 2. Systematic antidromic mapping techniques were used to map the axonal projections of 41 of these neurons within the diencephalon. Thirty-three neurons (80%) could be activated antidromically with currents < or = 30 microA only from points in the contralateral thalamus and are referred to as spinothalamic tract (STT) neurons. Eight neurons (20%) were activated antidromically with low currents from points in both the contralateral thalamus and hypothalamus, and these neurons are referred to as spinothalamic tract/ spinohypothalamic tract (STT/SHT) neurons. Three additional neurons were activated antidromically with currents < or = 30 microA only from points within the contralateral hypothalamus and are referred to as spinohypothalamic tract (SHT) neurons. The diencephalic projections of another 51 neurons were mapped incompletely. These neurons are referred to as spinothalamic/unknown (STT/ U) neurons to indicate that it was not known whether their axons ascended beyond the site in the thalamus from which they initially were activated antidromically. 3. For 31 STT neurons, the most anterior point at which antidromic activation was achieved with currents < or = 30 microA was determined. Fourteen (45%) were activated antidromically only from sites posterior to the ventrobasal complex (VbC) of the thalamus. Sixteen STT neurons (52%) were activated antidromically with low currents from sites at the level of the VbC, but not from more anterior levels. One STT neuron (3%) was activated antidromically from the anteroventral nucleus of the thalamus. 4. STT/SHT neurons were antidromically activated with currents < or = 30 microA from the medial lemniscus (ML), anterior pretectal nucleus (APt), posterior nuclear group and medial geniculate nucleus (Po/MG), and zona incerta in the thalamus and from the optic tract (OT), supraoptic decussation, or lateral area of the hypothalamus. No differences in the sites in the thalamus from which STT and STT/SHT neurons were activated antidromically were apparent. Five STT/SHT neurons (62%) were activated antidromically from points in the thalamus in the posterior diencephalon and from points in the hypothalamus at more anterior levels. Three STT/SHT neurons (38%) were activated antidromically with currents < or = 30 microA from sites in both the thalamus and hypothalamus at the same anterior-posterior level of the diencephalon. All three of these STT/SHT neurons projected to the intralaminar nuclei (parafascicular or central lateral nuclei) of the thalamus. 5. Seven STT/SHT neurons were tested for additional projections to the ipsilateral brain. Two (29%) were activated antidromically with currents < or = 30 microA and at longer latencies from sites in the ipsilateral diencephalon. One could only be activated antidromically from the hypothalamus ipsilaterally. The other was activated antidromically at progressively increasing latencies from points in the ipsilateral brain that extended as far posteriorly as the posterior pole of the MG. 6. Fifty-eight STT, STT/SHT …