摘要
本研究用顺行与逆行追踪相结合的双标技术对伏核下行投射纤维与中脑导水管周围灰质（ＰＡＧ）向中缝大核（ＮＲＭ）投射神经元和外侧缰核（ＬＨｂ）向ＰＡＧ投射神经元间的突触联系进行了观察。将顺行标记物ＰＨＡＬ电泳入伏核和逆行标记物ＨＲＰ分别注入ＮＲＭ或ＰＡＧ后，在ＰＡＧ的尾段腹外侧区和中缝背核（ＤＲ）或ＬＨｂ内侧部分别可见ＰＨＡＬ顺标终末与ＨＲＰ逆标神经元的主要分布区重叠。电镜下分别在ＰＡＧ的腹外侧区、ＤＲ或ＬＨｂ内侧部观察到ＰＨＡＬ顺标终末与ＨＲＰ逆标神经元的胞体和树突形成以非对称性为主的轴体和轴树突触。上述结果说明伏核的直接下行投射纤维主要与ＰＡＧ和ＤＲ内向ＮＲＭ投射神经元形成突触联系，伏核的部分下行投射纤维在ＬＨｂ内侧部中继后再间接投射到ＰＡＧ。
Employing a double labeling technique by combination of anterograde tracing with retrograde tracing, we investigated the synaptic connections between the descending fibers from the nucleus accumbens (Acb)and the projection neurons from the midbrain periaqueductal gray(PAG)to the nucleus raphe magnus(NRM)or the projection neurons from the lateral habenular nucleus (LHb)to the PAG. After injecting phaseolus vulgaris leucoagglutinin(PHA L)into the Acb and horseradish peroxidase (HRP)into the NRM or PAG, respectively, PHA L anterogeradely labeled fibers and terminals and HRP retrogradely labeled neurons overlapped mainly in the caudal segment of the ventrolateral subdivision(VLS)of the PAG and dorsal raphe nucleus(DR)or medial portion of the LHb, respectively. PHA L anterogradely labeled axon terminals mainly made asymmetrical axo somatic and axodendritic synapses with HRP retrogradely labeled neuronal cell bodies and dendrites within the VLS of the PAG, DR or medial portion of the LHb. The present results showed that direct descending fibers from the Acb to the PAG mainly terminated onto the neurons in the PAG and DR which sent projection fibers to the NRM, indirect descnding fibers relayed at the medial portion of the LHb, in turn, the neurons in the medial portion of the LHb which receied termination of the Acb descending fibers projected to the PAG. These results indicated that both direct and indirect descending projections from the Acb to the PAG and DR might regulate the neuronal activities within the PAG and DR.
出处
《中国疼痛医学杂志》
CAS
CSCD
1998年第4期212-216,共5页
Chinese Journal of Pain Medicine
基金
国家自然科学基金
关键词
伏核
中脑导水管
周围灰质
中脑边缘镇痛
Nucleus accumbens
Periaqueductal gray
Habenular nucleus
Nucleus raphe magnus
Mesolimbic loop of analgesia
Rat
