ABSTRACT
L6.A longitudinal column of HRP-labeled motoneurons was found in the dorsolateral and mediolateral portions of the spinal cord,distributing in the lamina Ⅸ from the caudal L4 to the rostral L6.Additionally,the transganglionic HRP-labeled central projection axonal terminals were found to be dense in the central part of laminae Ⅰ-Ⅱ from L4 to the rostral L6,and to scatter in the central part of gracile nucleus.Conclusion HRP-labeled primary afferent and efferent innervating acupoint "Taixi"(KI 3) are DRGs of L4-L6,the dorsolateral and mediolateral motoneuron columns of L4-L6,and the centrally projecting axonal terminals of laminae Ⅰ-Ⅱ of the spinal cord and the gracile nucleus.
ABSTRACT
The efferent and afferent projections of the hyperstriatum ventrale, pars caudal nucleus (HVc) in carduelis spinus were investigated using anterograde and retrograde HRP tracing techniques. After injecting HRP into the HVc, anterogradely labelled fibers and terminals were observed in the robust nucleus of the archistriatum (RA), tractus archistriatum dorsalis (DA) and the area X of lobus parolfactorius. The dense retrogradely labelled cell bodies were found in medial magnocellular nucleus of the anterior neostriatum (mMAN), nucleus interfacialis (NIf) of midneostriatum, telencephalic auditory area--field L of the neostriatum, and locus ceruleus (LoC) of pons. All these projections were ipsilateral. Based on the present and previous studies, the authors got the following understanding: 1. The HVc projects to the high vocal control centre--RA. This proved that the HVc is also a high vocal control nucleus. 2. The HVc receives afferent projections from the telencephalic auditory area--field L. It indicates that there are direct connection between the two high centres of audition and vocal control nuclei in telencephalon. 3. This study demonstrated that the HVc receives afferent projection from the LoC for the first time. According to the fact, we presume that HVc may be involved in the neural regulations of vegetative function and emotional reactions. 4. The HVc also receives afferent projections from the mMAN and NIf of neostriatum, and from the Uva of the thalamus. On the other hand the HVc projects to area X. Since the mMAN, NIf, Uva and area X are vocal learning and memory centres, therefore the HVc may be also involve in vocal learning and memory functions.
ABSTRACT
Objective To examine the synaptic structure and glutamatergic transmitter of the pathway linking the anterior thalamic nucleus(ATN) and the subicular complex. Methods The HRP tracing and post embedding immunogold technique were used. Results In the anterior thalamic nucleus,anterograde HRP labelled terminals contained clear round synaptic vesicles and several mitochondria,and formed asymmetric synaptic contacts with HRP-labelled or non-HRP labelled dendrites.The highest densities of immunogold particles following glutamate immunostaining were found in HRP-labelled terminals and similar axon terminals devoid of HRP reaction product,They formed asymmetric synaptic contacts(Gray type Ⅰ) with dendrites.The average density of those immunogold particles was more than 3 times higher than that of the gold particles in the dendrites of their contacts and over 6 times higher than that of the particles in the terminals that formed symmetric synapses(Gray type Ⅱ).In two serial GABA immunogold reactive sections,Gray tpye Ⅱ terminals were heavily labeled whereas Gray type Ⅰterminals displayed a very slight labelling.In glutamate immunogold reactive sections,Gray type Ⅱ terminals were slightly labeled.A GABA positive terminal which formed symmetric synapses with HRP-labeled dendrites and the terminal which formed asymmetric synapses converged on the same dendrite.Conclusion The terminals of projection neurons in the pathway linking the anterior thalamic nucleus and the subicular complex are glutamatergic.In anterior thalamic nucleus corticothalamic projection neuron terminals form asymmetric synaptic contacts with HRP-labelled thalamocortical projection neurons by axo-dendritic synapses.
ABSTRACT
By using a highly sensitive HRP-TMB method, the present study found parasympathetic preganglionic neurons innervating rat stomach originated from the dorsal motor nucleus of the vagus(DMV), ambiguus nucleus(AM), reticular formation between DMV and AM(RF). rostroventrolateral reticular nucleus (RVL), lateral parvocelluler reticular nucleus (LRP), paraependymal nucloeus of the vagus (PEV), intercalated nucleus(IC) and retroambiguus nucleus(RA). There was a specific representation area of the stomach in the DMV between 0.3-0.6mm rostral to obex, and the different parts of the stomach had topographical organization within this area. The lateral portion of the DMV mainly innervated the forestomach, the medial and medial-middled portion of the DMV predominantly projected to the antrum/pylorus and corpus, respectively. The right and the left DMV did not show difference in innervating the forestomach and antrum/pylorus, but the corpus was mainly innervated by the right DMV. RF only projected to the forestomach and the corpus. RVL and RA only innervated the forestomach. AM, PEV and IC innervated all the three parts. The relationship between the different neuronal types of the DMV and the different parts of the stomach was first discussed in this paper. The forestomach, corpus and antrum/pylorus received their inputs mainly from the large and small neurons, respectively. The dentrites of the DMV contacting CSF were confirmed.
ABSTRACT
The projection from the nucleus of solitary tract (Sol) to the nucleus accumbens (Acb) was examined by using HRP retrograde and anterograde tracing combined with immunocytochemical double-labeling technique. The following results were obtained: (1) when WGA-HRP was injected into the caudal part of the Sol, the labeled fibers, terminals and cell bodies were found in the ventromedial area of the caudal Acb. After injecting HRP into the ventromedial area of the caudal Acb, labeled cell bodies and terminals were found in the ipsilateral and contralateral caudal part of the Sol,mainly in the commissure nucleus and the medial subnucleus of nucleus of solitary tract. (2) After injecting HRP into the Acb and combined with immunocytochemical method, many HRP-TH, HRP-NT, and HRP-CCK double-labeled cell bodies were found in the caudal part of the Sol. The number of the HRP-TH double-labeled cell bodies was most numerous, HRP-NT cells was next and HRP-CCK cells was even less.
ABSTRACT
Projections from substance P (SP)-and cholecystokinin (CCK) containing neurons in the periaqueductal gray(PAG)and Edinger-Westphal(E-W)nucleus to the spinal cord were studied by means of the combining method of HRP tracing with immunocytochemistry in rats. The results showed that a few neurons in the ventrolateral region of PAG projected bilaterally to the cervical, thoracic and lumbar segments of the spinal cord, with the predominant projections from the ipsilateral side. The authors reported that these descending projection neurons showed SP-like immunoreactivity for the first time(account for 48%). The neurons of E-W nucleus projected diffusely to all segments of the spinal cord contained SP (70%) or CCK (73%) respectively, suggesting that at least a part of E-W neurons projecting to the spinal cord contain both SP and CCK.
ABSTRACT
The projections from the nucleus tractus solitarii (NTS) and the nuclei parabrachiales (PB) to the nucleus accumbens (Acc) in the rat have been visulized using anterograde and retrograde HRP tracing techniques. After injecting HRP into the Acc, retrogradely labelled neurons were observed in bilateral PB and NTS with ipsilateral predominance. The labelled neurons were concentrated in the following areas of the PB and NTS: the waist area of the caudal PB, the external subnucleus and other part of the nucleus medialis parabrachialis (PBm), the external, central, and internal subnuclei of the nucleus lateralis parabrachialis (PB1) and the medial subnucleus of the caudal NTS (NTSm). After injecting HRP into the NTSm and commissural nucleus of the NTS, anterogradely labelled terminals were found bilaterally in the PBm and the ventral 3/4 area of the PB1. The densest sites occupied the waist area, the external, central, and internal subnuclei of the PB1. The density of the labelled terminals on the ipsilateral side was little higher than that on the contralateral side. The results indicate that there are two possible pathways from the NTS to the Acc, the one is the direct projection from the medial subnucleus of the caudal NTS to the Ace, the other is an indirect one, i. e. from the medial subnucleus and commissural nucleus of the caudal NTS to the waist area of the caudal PB, the external subnucleus, the dorsal part of the PBm, the external, central, and internal subnuclei of the PB1, where the NTS projection is. presumed to be relayed, and then, project from the PB to the Acc. This connection may be involved in the neural regulation of visceral and locomotor activities.