摘要
Neural pathways and synaptic connections from the trigeminal mesencephalic nucleus (Vme) neurons to the cranial motor nuclei were studied in the rat using double labelling methodologies of intracellular Neurobiotin staining combined with retrograde horseradish peroxidase (HRP) transport, anterograde biotinylated dextran amine (BDA) tracing combined with retrograde HRP transport, and a dual fluorescent labelling of BDA anterograde combined tracing with Cholera Toxin B (CTB) retrograde transport. Direct projections and synapses were demonstrated from Vme neuronal boutons to motoneurons (MNs) of the trigeminal motor nucleus (Vmo), the hypoglossal nucleus (XII) and the ambiguus nucleus (Amb). Indirect projections and pathways from Vme neurons to the cranial motor nuclei including Vmo, XII, the facial nucleus (VII) and the cervical spinal cord (C 1～5 ) were seen to relay on their premotor neurons. The premotor neurons of above cranial motor nuclei were overlapped in bilateral premotor neuronal pool including the parvocellular reticular formation (PCRt) and its alpha division (PCRtA), the dorsomedial part of the spinal trigeminal nucleus oralis (Vodm), and interpolaris (Vidm), the medullary reticular nucleus dorsal division (MdD), the supratrigeminal region (Vsup) and the dorsomedial part of the principal trigeminal sensory nucleus (Vpdm). Synapses between Vme neuronal boutons and Vmo and XII MNs and XII premotor neurons were predominantly asymmetric. There were four types of synaptic organizations, i.e. synaptic convergence; synaptic divergence presynaptic inhibition and afferent feedforward inhibition seen between Vme boutons and Vmo, XII MNs and between Vme boutons and XII premotor neurons. The results of present studies have demonstrated direct pathways from the trigeminal proprioceptive afferents to Vmo, XII and Amb MNs, and indirect pathways from the trigeminal proprioceptive afferents to bilateral Vmo, XII, VII and C 1～5 via their premotor neurons. It provides neuroanatomical network to elucidate trigeminal proprioceptive afferents coordinate oral motor behaviors.
Neural pathways and synaptic connections from the trigeminal mesencephalic nucleus (Vme) neurons to the cranial motor nuclei were studied in the rat using double labelling methodologies of intracellular Neurobiotin staining combined with retrograde horseradish peroxidase (HRP) transport, anterograde biotinylated dextran amine (BDA) tracing combined with retrograde HRP transport, and a dual fluorescent labelling of BDA anterograde combined tracing with Cholera Toxin B (CTB) retrograde transport. Direct projections and synapses were demonstrated from Vme neuronal boutons to motoneurons (MNs) of the trigeminal motor nucleus (Vmo), the hypoglossal nucleus (XII) and the ambiguus nucleus (Amb). Indirect projections and pathways from Vme neurons to the cranial motor nuclei including Vmo, XII, the facial nucleus (VII) and the cervical spinal cord (C 1～5 ) were seen to relay on their premotor neurons. The premotor neurons of above cranial motor nuclei were overlapped in bilateral premotor neuronal pool including the parvocellular reticular formation (PCRt) and its alpha division (PCRtA), the dorsomedial part of the spinal trigeminal nucleus oralis (Vodm), and interpolaris (Vidm), the medullary reticular nucleus dorsal division (MdD), the supratrigeminal region (Vsup) and the dorsomedial part of the principal trigeminal sensory nucleus (Vpdm). Synapses between Vme neuronal boutons and Vmo and XII MNs and XII premotor neurons were predominantly asymmetric. There were four types of synaptic organizations, i.e. synaptic convergence; synaptic divergence presynaptic inhibition and afferent feedforward inhibition seen between Vme boutons and Vmo, XII MNs and between Vme boutons and XII premotor neurons. The results of present studies have demonstrated direct pathways from the trigeminal proprioceptive afferents to Vmo, XII and Amb MNs, and indirect pathways from the trigeminal proprioceptive afferents to bilateral Vmo, XII, VII and C 1～5 via their premotor neurons. It provides neuroanatomical network to elucidate trigeminal proprioceptive afferents coordinate oral motor behaviors.
出处
《神经解剖学杂志》
CAS
CSCD
北大核心
2003年第4期438-447,共10页
Chinese Journal of Neuroanatomy
关键词
突触联系
神经通道
三叉神经
神经元
trigeminal proprioception, cranial motoneuron, premotor neuron sensorimotor integration, synaptic organization
