-
[show abstract]
[hide abstract]
ABSTRACT: Although cervical spinal tissues are rich in sensory and sympathetic fibers, which play a significant role in clinical phenomena, there is little information available regarding their anatomical characteristics. In this study, we compared the innervation of the cervical dura mater and the posterior longitudinal ligament (PLL) to that after removal of the stellate ganglion to determine whether the anatomical background plays a significant role in clinical manifestations. Immunoreactivities for calcitonin gene-related peptide (CGRP) and substance P (SP) were used as sensory markers, and immunoreactivity for neuropeptide Y (NPY) was used as a sympathetic marker. Sensory fibers in the cervical dura mater were distributed within each cervical segment, but those in the PLL extended beyond the segmental borders. A dense sensory fiber network forming a single layer was seen at the intervertebral disc region in the cervical PLL, whereas sympathetic fibers in this region were sparsely distributed. Sympathetic fibers were distributed not only around the vascular wall but also in the region independent from vessels, and some occasionally ran together with sensory fibers in both the dura mater and the PLL. Removal of the stellate ganglion had little effect on the distribution of sensory fibers but denervated the sympathetic fiber networks in the region independent from vessels of the upper ipsilateral cervical PLL. In conclusion, the cervical dura mater and the PLL have different sensory and sympathetic innervations. Sympathetic fibers pass through the stellate ganglion to project to the region independent from vessels in the upper cervical PLL. Clinical symptoms may be attributed to this characteristic innervation of the cervical spine.
The Journal of Comparative Neurology 06/2001; 434(1):86-100. · 3.81 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Sensory innervation of the lumbar dura mater passing through the sympathetic trunk was investigated by neuronal tracing and immunohistochemical methods.
To assess an anatomic basis indicating that sympathetic block in the higher lumbar region is effective for patients with low back pain.
Low back pain is elicited by disorder or mechanical stimulation of the lumbar dura mater. Clinically, the authors often have observed patients in whom root block at the responsible level or sympathetic block at the higher level could relieve low back pain. Therefore, there may be two different sensory routes, the segmental innervation at the same level and nonsegmental fibers from higher dorsal root ganglia.
The tracers were injected into the sympathetic trunk between L3 and L4 of rats. The lumbar dorsal root ganglia and dura mater were examined, and labeled cells were measured in size and the distribution. To establish the sensory property, the materials were processed in immunohistochemistry for calcitonin gene-related peptide.
Many small- to medium-sized neurons were retrogradely labeled L1 and L2 dorsal root ganglia after injection into the sympathetic trunk. The anterogradely labeled fibers were found in the dura mater at L4 and L5. Some of the labeled neurons and fibers were immunoreactive for calcitonin gene-related peptide.
Sensory fibers from the upper lumbar ganglia innervated the lower lumbar dura mater directly. These sensory nerves may mediate low back pain and possibly interact with sympathetic nerves.
Spine 05/2000; 25(7):776-82. · 2.08 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Sensory innervation in the cervical dura mater of rats was investigated immunohistochemically in whole tissues and transverse sections of the decalcified vertebral column.
To investigate the origin and distribution of sensory innervation in the cervical dura mater.
It has been generally accepted that irritation of the cervical structures is one of the major causes of pain in the neck and the upper extremities. Sensory fibers in the cervical dura mater are possible mediators of pain. However, there is little information about sensory innervation in the cervical dura mater, including the epiradicular sheath.
Ten Wistar rats were used for wholemount immunohistochemical observations of the cervical dura mater. The vertebral columns of five rats were processed for immunohistochemistry after decalcification. In all specimens, sensory fibers were demonstrated by the peptide immunohistochemistry, and sensory innervation was examined.
The cervical dura mater was arbitrarily divided into three areas: ventral, dorsal, dorsal root ganglion. A large number of fibers were in the dorsal root ganglion area and were distributed in the corresponding segments. Some calcitonin gene-related peptide immunoreactive fibers in the dorsal root ganglion were directly innervated from dorsal root ganglion area neurons and did not form nerve bundles, similar to the sinuvertebral nerve. Several immunoreactive fibers were seen in the ventral area; fibers were rarely observed in the dorsal area.
A large number of sensory fibers are segmentally distributed in the cervical dura mater, and some of them are directly traced from dorsal root ganglion neurons.
Spine 08/1998; 23(14):1524-9; discussion 1529-30. · 2.08 Impact Factor
-
Annals of the New York Academy of Sciences 06/1998; 839:615-8. · 3.15 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: From indirect evidence we have proposed that cholinergic versus non-cholinergic neurons in the laterodorsal tegmental nucleus can be distinguished with the duration of their extracellularly recorded action potentials, "broad" spikes for the former, "brief" for the latter. To test this assumption more directly, we labelled single neurons recorded extracellularly in and around the laterodorsal tegmental nucleus with biocytin or neurobiotin, and processed the sections with reduced nicotinamide adenine dinucleotide phosphate-diaphorase, a proven marker for cholinergic neurons in the laterodorsal tegmental nucleus. Biocytin or neurobiotin which was deposited at the site of recording was incorporated into single neurons. Among 171 trials (91 for broad-spike and 80 for brief-spike neurons), marking was successful in 68 cases (29 for broad-spike and 39 for brief-spike neurons). Almost all (21/22) of the broad-spike neurons located within the laterodorsal tegmental nucleus were positive for reduced nicotinamide adenine dinucleotide phosphate-diaphorase staining, i.e. they were cholinergic, while all of the brief-spike neurons in and outside of the laterodorsal tegmental nucleus lacked the diaphorase activity, and were thus non-cholinergic. The present study shows that, after extracellular labelling of single neurons by biocytin or neurobiotin, cholinergic neurons in the laterodorsal tegmental nucleus are confidently distinguished from non-cholinergic ones in the corresponding area with their spike shapes. It is also shown that the cholinergic neurons distinguished by this criterion are characterized by their tonic firing at slightly lower rate and larger cell size than the brief-spike non-cholinergic ones.
Neuroscience 04/1998; 83(4):1105-12. · 3.38 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: After inoculation of a highly neuro-invasive strain of herpes simplex virus (HSV) type 2 (186) into the mouse hind-paw planter skin, many virus-positive neurons and glial cells were detected in the dorsal root ganglia (DRGs) and lumbar spinal cord by immunohistochemistry for HSV-2 antigen. A number of apoptotic cells were also observed in the spinal cord and DRGs by the terminal dUTP nick-end-labeling (TUNEL) method. Double labeling with the immunohistochemistry for HSV-2 and the TUNEL method revealed further that some glial and neuronal cells in the spinal cord, either infected or non-infected by HSV-2, showed apoptotic signs. In DRGs, however, apoptosis was detected in no neuronal cells, although some of HSV-2 -infected glial cells were apoptotic.
Neuroscience Letters 07/1997; 228(2):99-102. · 2.11 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: After the inoculation of a highly attenuated strain of herpes simplex virus (HSV) type 1 into the mouse hind-paw planter skin, a few neurons and glial cells were viral antigen-positive in the dorsal root ganglia (DRGs) and anterior horn of L4 and L5 segments of the lumbar spinal cord. Fos-containing nuclei, however, were not found in the DRGs or the lumbar cord segments. After the inoculation of a highly neuroinvasive strain of HSV type 2, many virus-positive neurons and glial cells were detected in the DRGs, anterior and posterior horns at L4 and L5; Fos-containing nuclei were also observed in spinal neurons except for motoneurons. The results indicate that transneuronal infection of HSV induces Fos expression in spinal neurons.
Neuroscience Letters 10/1996; 216(1):61-4. · 2.11 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The distribution and density of nerve innervation in the lumbar dura mater after lumbar sympathectomy were assessed in wistar rats.
To provide basic information on the interaction between sympathetic and sensory nerves in patients with low back pain.
Many studies have indicated that the sinuvertebral nerve has an important role in innervating the tissues around the vertebrae. However, the origin, innervating pattern, and connections between the nerves are still controversial. It is well known that pain is often accompanied with sympathetic symptoms and exaggerated by sympathetic stimuli. Occasionally, anesthetic block at the L2 or L3 sympathetic ganglion relieves low back pain or symptoms associated with low back pain. The authors assessed the changes of the density and distribution of nerve innervation of the lumbar dura mater after lumbar sympathectomy.
Normal adult rats were sympathectomized at L2-L3. The threshold for thermal noxious pain by hot-plate analgesia test and changes in neuropeptides in the lumbar dura mater and dorsal root ganglia using light microscopic immunohistochemistry were assessed and compared with control rats.
In the hot-plate analgesia test, sympathectomized rats increased their hot-plate latency time compared with that of sham-operated rats. Density of calcitonin gene-related peptide immunoreactive fibers in sympathectomy side of the lumbar dura mater decreased to 45.5% compared with the contralateral side. The number and size of calcitonin gene-related peptide immunoreactive cells in dorsal root ganglia showed no difference between sympathectomized and contralateral side.
Sympathectomy increased the pain threshold and made the sympathectomized rats hypesthetic. A large numbers of sensory fibers innervated the lumbar dura mater via L2-L3 sympathetic nerve in rats. Sympathectomy reduced the number of these nerve fibers in the lumbar dura mater. Sympathetic nerves may play an important role for low back pain involving the lumbar dura mater.
Spine 05/1996; 21(8):925-30. · 2.08 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Frogs can adapt to their background by making their skin color lighter or darker as necessary, and this adaptation is regulated by MSH. We investigated the mechanism inhibiting MSH release from the pars intermedia (PI) of the pituitary gland in frogs (Rana nigromaculata) by ultrastructural immunohistochemistry and bioassay using the melanophore index. The PI contained fibers immunoreactive for tyrosine hydroxylase, gamma-aminobutyric acid (GABA), and neuropeptide Y, which made synaptic contacts with MSH cells. The synapses had an asymmetric profile with small round and large-cored synaptic vesicles. The skin of frogs adapted to a white background became darker after administration of 6-hydroxydopamine or autografting of the PI into the anterior chamber of the eye. The skin of autografted frogs became lighter after the administration of dopamine or GABA into the anterior chamber. Lightening of skin color with dopamine was inhibited by a D2 receptor antagonist (sulpiride), and the effect of GABA was blocked by both sulpiride and a GABAA receptor antagonist (bicuculline). These results indicate that MSH release from the PI in frogs may be inhibited by dopaminergic nerves via the D2-like receptor and by GABAergic nerves via the D2-like and GABAA receptors.
Endocrinology 01/1996; 136(12):5260-5. · 4.46 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A combination of retrograde cell body labeling and immunohistochemistry was employed to elucidate how oxytocinergic fibers make contact with sympathetic preganglionic neurons (SPNs) in the rat spinal cord from T1 to T4. SPNs were labeled retrogradely using cholera toxin subunit B (CTb) or horseradish peroxidase-conjugated CTb. Oxytocin-immunoreactive (ir) fibers were found in the intermediate zone, including the sympathetic preganglionic subnuclei. In the central autonomie nucleus and the intercalated nucleus, brown-stained oxytocin-ir varicosities or terminals were frequently observed to stud black-stained dendrites of SPNs. Electron microscopical observations showed that oxytocin-ir terminals form synapses with dendrites or soma of the sympathetic preganglionic neurons. The terminals contained numerous small clear round vesicles and a few large, cored vesicles. These results clearly show that a large proportion of SPNs are innervated by oxytocin-containing fibers. The origin of these fibers is discussed, and it is concluded that they are probably descending fibers from the paraventricular nucleus of the hypothalamus.
Experimental Brain Research 10/1995; 107(1):9-16. · 2.39 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Synaptic and ultrastructural organization in the intermediolateral nucleus (IML) of rat were investigated with electron microscopy combined with pre-embedding immunohistochemistry for substance P (SP)-receptor (SPr). SPr immunoreactivity in IML was found in the vicinity of the cellular membrane of the perikarya and dendritic profiles of the small sized neurons, ranging from 15 to 25 microns in length. A SPr-immunoreactive (SPr-ir) soma had symmetric or asymmetric synaptic contacts with three to five unlabeled axon terminals. Two different types of axon terminals made synapses on the SPr soma, one contained 20-30 nm pleomorphic vesicles and large dense cored vesicles and the other contained clear pleomorphic vesicles of 30-50 nm in size. Occasionally, SPr-ir dendrites are very closely apposed to the blood capillary. Our present results suggested the possibility that the IML SPr-ir neurons might be activated by several kinds of synaptic inputs and SP provided from blood flow.
Neuroscience Letters 10/1995; 197(2):117-20. · 2.11 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The innervation of the shoulder joint of the rat was investigated. Nerve origin was assessed by injection of a neuronal tracer (WGA-HRP) into the shoulder joint cavity and calcitonin gene-related peptide (CGRP), which is known to be present in some sensory neurons, was detected immunohistochemically with an anti-CGRP antibody. In the ipsilateral sympathetic and dorsal root ganglia, 133-312 and 12-55 nerve cell bodies were respectively labeled by injection of the tracer. In the sympathetic ganglia, 83% of all labeled cells were found in the stellate ganglion and 17% in the superior cervical ganglion. In the dorsal root ganglia, 75% of the labeled cells were found in C4 and the neighboring ganglia (C4-C5), while the rest were observed in C6-8 and T3. This suggested that the origin of sensory innervation for the shoulder joint was mainly in the mid-cervical cord. CGRP-immunoreactive fibers were found in the synovial capsule of the shoulder joint. These fibers were fine and resembled type 4 axons as classified by Brodal, i.e., nerve related to pain sensation. These findings indicate that sensory nerves from the mid-cervical cord and sympathetic nerves from the cervical ganglion are distributed to the shoulder joint. It is possible that these nerves are related to symptoms such as pain in patients with "frozen" shoulder or other diseases.
Anatomy and Embryology 06/1995; 191(5):465-9. · 1.42 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The rat shoulder joint capsule is innervated by thin sympathetic and sensory nerve fibers, most of which contain calcitonin gene-related peptide (CGRP). In order to establish the origin and distribution of CGRP-immunoreactive (IR) fibers, wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP) was injected into the shoulder joints of rats via a dorsal surgical approach. After WGA-HRP injection, the cervico-thoracic dorsal root ganglia (DRG) were removed and processed using both HRP histochemistry and CGRP immunohistochemistry. In the C4 to C7 DRG, small to medium-sized neurons (20-40 microns) were labeled by this combined method. The number and size of the labeled neurons were measured in the cervical 4th-7th DRG. The number of double-labeled neurons was one quarter of the total number of HRP-labeled neurons and 1/20 of the CGRP-IR neurons. Most of the double-labeled cells were located in the C6 ganglion, and the mean number of double-labeled neurons was 13 at this level. This distribution and function of the CGRP-IR fibers in the rat shoulder joint capsule are discussed.
Anatomy and Embryology 06/1995; 191(5):471-6. · 1.42 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A combination of retrograde cell body labeling and immunohistochemistry was employed to elucidate how oxytocinergic fibers make contact with sympathetic preganglionic neurons (SPNs) in the rat spinal cord from T1 to T4. SPNs were labeled retrogradely using cholera toxin subunit B (CTb) or horseradish peroxidase-conjugated CTb. Oxytocin-immunoreactive (ir) fibers were found in the intermediate zone, including the sympathetic preganglionic subnuclei. In the central autonomic nucleus and the intercalated nucleus, brown-stained oxytocin-ir varicosities or terminals were frequently observed to stud black-stained dendrites of SPNs. Electron microscopical observations showed that oxytocin-ir terminals form synapses with dendrites or soma of the sympathetic preganglionic neurons. The terminals contained numerous small clear round vesicles and a few large, cored vesicles. These results clearly show that a large proportion of SPNs are innervated by oxytocin-containing fibers. The origin of these fibers is discussed, and it is concluded that they are probably descending fibers from the paraventricular nucleus of the hypothalamus.
Experimental Brain Research 02/1995; 107(1):9-16. · 2.39 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In guinea pigs, intracellular labeling of the dorsal root ganglion (DRG) cells with Phaseolus vulgaris-leucoagglutinin (PHA-L) was used to demonstrate the central projections of somatic and visceral afferent C-fibers. The terminations of the afferent fibers were analyzed qualitatively and quantitatively with the aid of camera lucida drawings. Terminal branches of C-fibers of both somatic and visceral origin were, in general, distributed in accord with the organization of the neuropil in lamina of the spinal cord. Terminal boutons arranged from longitudinally coursing fibers were distributed in lamina I, while boutons in lamina II were scattered in an apparent random fashion. The synaptic enlargements were counted in gray matter of the spinal dorsal horn and measured on each terminal branch of a fiber. All synaptic boutons (over one thousand) of somatic fibers were found in the superficial dorsal horn (laminae I and II). More than 60% of the synaptic enlargements of the visceral afferents also were localized superficially (lamina I and adjacent dorsal funiculus) while 10-20% of the visceral enlargements appeared in deeper layers of the spinal cord. Boutons of somatic C-fibers were larger than those of visceral origin. Quantitative data of the unmyelinated afferent fibers are discussed in the context of the sensory functions of myelinated afferent fibers.
The Journal of Comparative Neurology 07/1993; 332(3):315-25. · 3.81 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The descending projection of the hypothalamic paraventricular nucleus (PVN) to the sympathetic preganglionic neurons (SPNs) in the upper thoracic cord of the rat was studied. PVN-fibers were labeled by anterograde transport of Phaseolus vulgaris leucoagglutinin (PHA-L), while SPNs were retrogradely labeled with cholera toxin subunit B (CTb) which was injected into the superior cervical ganglion. SPNs labeled with CTb were mainly observed in the nucleus intermediolateralis (IML) pars principalis and pars funicularis, and a small number of them were in the nucleus intercalatus (IC) and central autonomic nucleus (CA). SPNs found in the IML had dendrites that projected in various directions. Five types of dendritic projections were noted: medial, rostral, caudal, lateral (including dorsolateral) and ventral. Longitudinal dendritic bundles interconnected each cell cluster in the IML. Medial dendrites of the IML, together with dendrites of the IC and CA, formed transverse dendritic bundles extending from the IML to the central canal. The transverse dendritic bundles disentangled near the midline and formed a loose dendritic plexus in the region just dorsal to the central canal. PVN-fibers labeled with PHA-L were observed primarily in lamina I and intermediate gray (lamina VII). Although varicose PVN-fibers and SPNs coexisted in the IML, the tight packing of the dendritic bundles prevented any clear demonstration of direct contacts between them. On the other hand, PVN-fibers were occasionally found to appose and wind around the primary or secondary dendrites of some SPNs of the CA and IC. These dendrites were studied with varicosities of PVN-fibers for a short length, and terminal boutons of PVN-fibers were also seen to make contact directly with the dendrities. The results of this study substantiated a direct connection between the PVN and SPNs, using a combination of immunohistochemical techniques for PHA-L and CTb. The possible involvement of a direct pathway from the PVN to SPNs in cardiovascular regulation is discussed.
Experimental Brain Research 02/1991; 85(1):10-20. · 2.39 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A ladder-like pattern of distribution of sympathetic preganglionic neurons (SPNs) was compared with that of monoaminergic terminals in the upper thoracic spinal cord of the rat. SPNs were identified by a retrograde labeling with cholera toxin subunit B (CTb) injected into the superior cervical ganglia of both sides. Monoaminergic terminals were stained immunohistochemically by using antisera raised against 5-hydroxy-tryptamine (5-HT) or dopamine-beta-hydroxylase (DBH). SPNs showing full dendritic arbors were found in all of the sympathetic preganglionic nuclei. They formed a ladder in the horizontal plane. The nucleus intermediolateralis was connected with the central autonomic nucleus by many transverse dendritic bundles. Photomontages of serial sections of material stained alternatively with antisera against CTb and 5-HT or DBH clearly showed a close correlation between SPNs and monoaminergic terminals. There is no transverse dendritic bundle of SPNs without the accompaniment of monoaminergic terminals.
Experimental Brain Research 02/1991; 86(1):224-8. · 2.39 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The descending projection of the hypothalamic paraventricular nucleus (PVN) to the A5 area was elucidated using a technique that combines retrograde labeling with horseradish peroxidase (HRP), anterograde labeling with PHA-L (Phaseolus vulgaris leucoagglutinin and immunohistochemistry for dopamine-beta-hydroxylase (DBH). Following an iontophoretic injection of PHA-L into the PVN, HRP was applied to the greater petrosal nerve. Frozen sections of the hypothalamus and the caudal pons were first treated according to a protocol for HRP histochemistry using tetramethylbenzidine with cobalt-enhanced diaminobenzidine, and then they were processed for displaying PHA-L, and then for DBH immunohistochemistry. PHA-L labeled fibers from the PVN were observed in a ventrolateral part of the pontine reticular formation corresponding to the A5 area, where they give rise to a dense network around the cells of origin of the greater petrosal nerve (GPN cells) and DBH-positive cells. Terminals or varicosities labeled with PHA-L were preferentially observed around the somata of GPN cells, suggesting direct contact. However, apparent contact between both elements was hardly ever observed. On the other hand, terminals or varicosities were occasionally observed in close relation to DBH-positive cells. These results suggest that descending fibers of the PVN project more strongly to GPN cells than to DBH-positive cells. The relationship of this fiber pathway to control of the secretomotor or cardiovascular systems is discussed.
Experimental Brain Research 02/1990; 82(3):513-8. · 2.39 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: 1. In the guinea pig, the central projections of somatic and visceral C-afferent fibers were compared by tracing arborizations labeled through injection of Phaseolus vulgaris leucoagglutinin (PHA-L) intracellularly into single neurons of the 13th thoracic dorsal root ganglia (DRG). 2. Two of 27 somatic C-afferent neurons that responded to electrical stimulation of the 13th thoracic (subcostal) nerve (conduction velocity: 0.69 +/- 0.14 m/s, mean +/- SD) were well enough marked to allow delineation of their central processes. In both cases, the entering axon ran rostrally, giving off branches that converged on a single terminal field located in the substantia gelatinosa (lamina II) with some extension in lamina I. The terminal field in each case extended approximately 400 microns rostrocaudally and 100 microns mediolaterally. 3. Intracellular recordings were obtained from 31 afferent units that responded to electrical stimulation of the celiac ganglion. Units with onset latencies of greater than 15 ms were classified as having visceral C-afferent fibers because the shortest course from the celiac ganglion stimulation electrodes to the DRG was greater than 7 mm (i.e., a conduction velocity of less than 0.5 m/s). 4. Seven visceral C-afferent fibers were labeled well enough to follow their central trajectories. Each had a main ascending and a descending central branch. Each main branch in turn issued several collaterals that terminated in the superficial dorsal horn (laminae I and II), laminae IV, V, and X, and occasionally in the dorsal and lateral funiculi. A few collaterals reached the contralateral laminae V and X.(ABSTRACT TRUNCATED AT 250 WORDS)
Journal of Neurophysiology 11/1989; 62(4):834-40. · 3.32 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A hypothalamic projection to the nucleus raphe pallidus of the medulla was examined using the anterograde tracing technique based on Phaseolus vulgaris leucoagglutinin (PHA-L) in the rat. After the iontophoretic application of PHA-L to the dorsal hypothalamic area, labeled fibers that finally ended in the nucleus raphe pallidus were observed descending through the most medial part of the ventral tegmental area and the nucleus reticularis tegmenti pointis to reach the medial aspect of the pyramid. Many varicose fibers forming a loose plexus were observed in the nucleus raphe pallidus, especially ventrally. The ventral surface of the pyramid and the most ventral region of the nucleus reticularis paragigantocellularis lateralis (PGCL) contained labeled varicose fibers. At the electron microscopic level, the labeled profiles in the nucleus raphe pallidus were small-sized unmyelinated axons and axon terminals. Labeled axon terminals containing spherical synaptic vesicles formed synapses on spine-like protrusions or small-sized dendritic shafts. These results strongly indicate that neurons in the dorsal hypothalamic area have a direct connection with neurons in the nucleus raphe pallidus and the ventral part of the PGCL. The possible involvement of this pathway in cardiovascular regulation was discussed.
Experimental Brain Research 02/1989; 75(1):40-6. · 2.39 Impact Factor
