| 1. |
- Fundin, Bengt T., et al.
(författare)
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A comprehensive immunofluorescence and lectin binding analysis of intervibrissal fur innervation in the mystacial pad of the rat
- 1997
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Ingår i: Journal of Comparative Neurology. - 0021-9967 .- 1096-9861. ; 385:2, s. 185-206
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Tidskriftsartikel (refereegranskat)abstract
- The innervation of the intervibrissal fur in the mystacial pad of the rat and mouse wasexamined by immunofluorescence with a wide variety of antibodies for neuronal relatedstructural proteins, enzymes, and peptides as well as for lectin binding histofluorescence with Griffonia simplicifolia (GSA). Anti-protein gene product 9.5 (PGP) immunofluorescencelabeled all sets of axons and endings. The innervation in the upper dermis and epidermis wasdistributed through a four tiered dermal plexus. From deep to superficial, the second tier wasthe source of all apparent myelinated mechanorceptors, the third tier of nearly all thepeptidergic and GSA binding innervation, and the fourth tier of nonpeptidergic GSA negativeinnervation (peptide-/GSA-). Three types of mechanoreceptors—Merkel, transverse lanceolate,and longitudinal lanceolate endings—innervated guard hair follicles. All had similarlabeling characteristics for 160 kDa and 200 kDa neurofilament subunits, peripherin,carbonic anhydrase, synaptophysin, and S100. Palisades of longitudinal lanceolate endingswere part of piloneural complexes along circumferentially oriented sets of transverselanceolate endings, peptidergic free nerve endings (FNEs), and peptide-/GSA- FNEs. Thelongitudinal lanceolate endings were the only mechanoreceptors in the mystacial pad that haddetectable calcitonin gene-related peptide. The epidermis contained four types of unmyelinatedendings: simple free nerve endings (FNEs), penicillate endings, cluster endings and bushendings. Only the simple FNEs were clearly peptidergic. Virtually all others were peptide-/GSA-. Each bush ending was actually an intermingled cluster of endings formed by severalunmyelinated axons and occasionally anAd axon. In contrast to the other unmyelinated innervationto the epidermis, bush endings labeled with an antibody against the Schwann cell protein S100. Thenecks and mouths of follicles, as well as superficial vasculature, were innervated by a mixture of unmyelinated peptidergic and/or GSA labeled sensory and sympathetic axons. Small presumptivesweat glands were innervated by three sets of peptidergic axons of which one was immunoreactivefor somatostatin. Potential functions of the various sets of innervation are discussed.
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| 2. |
- Hallbeck, Martin, 1970-, et al.
(författare)
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Distribution of preprovasopressin mRNA in the rat central nervous system
- 1999
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Ingår i: Journal of Comparative Neurology. - 0021-9967 .- 1096-9861. ; 411:2, s. 181-200
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Tidskriftsartikel (refereegranskat)abstract
- Vasopressin released in the central nervous system has been shown to be involved both in homeostatic mechanisms (e.g., water balance, thermoregulation, cardiovascular regulation, metabolism, and antinociception) and in higher brain functions (e.g., social recognition and communication, and learning and memory). Many nuclear groups have been proposed to synthesize vasopressin, but available data are conflicting. We have used a sensitive in situ hybridization technique to identify the distribution of the neurons that may be the origin of the vasopressin in the central nervous system of the male Sprague-Dawley rat. Vasopressin mRNA-expressing neurons were most abundant in the hypothalamus (e.g., the paraventricular, supraoptic, and suprachiasmatic nuclei) but were also seen in the medial amygdaloid nucleus, the bed nucleus of stria terminalis, and the nucleus of the horizontal diagonal band. Previously unreported vasopressinergic neurons were seen in the entorhinal and piriform cortices, the ventral lateral portion of the parabrachial nucleus, the pedunculopontine nucleus, and the rostral part of the ventral periaqueductal gray matter and the adjacent portion of the mesencephalic reticular nucleus. Vasopressin mRNA expression suggestive of neuronal labeling was seen in the pyramidal layer of the CA1–3 fields and the dentate gyrus of the hippocampus. In addition, vasopressin mRNA expression, probably representing axonal mRNA, was detected over the hypothalamopituitary tract. No or insignificant preprovasopressin mRNA expression was present in the cerebellum, locus coeruleus, subcoeruleus, or the spinal cord. These findings provide novel information on the distribution of vasopressin neurons that are important for our understanding of how vasopressin acts in the brain.
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| 3. |
- Hallbeck, Martin, 1970-, et al.
(författare)
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Spinal cord-projecting vasopressinergic neurons in the rat paraventricular hypothalamus
- 1999
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Ingår i: Journal of Comparative Neurology. - 0021-9967 .- 1096-9861. ; 411:2, s. 201-211
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Tidskriftsartikel (refereegranskat)abstract
- The paraventricular hypothalamic nucleus (PVH) is a key structure for the maintenance of homeostasis. Homeostatic regulation includes modulation of signaling in the spinal cord. This may be exerted by neurons in the PVH with spinal projections. However, the PVH is not a homogeneous structure, but consists of anatomically and functionally distinct subdivisions. In this study, we have analyzed the distribution of spinal cord-projecting PVH neurons that express vasopressin, an important neuropeptide in autonomic regulation. Vasopressinergic neurons were identified with a radiolabeled riboprobe complementary to vasopressin mRNA combined with immunohistochemical labeling of retrogradely transported cholera toxin subunit b in spinally projecting neurons. More than 40% of the spinally projecting neurons in the PVH of naive Sprague-Dawley rats were found to express vasopressin mRNA. The lateral parvocellular subdivision and the ventral part of the medial parvocellular subdivision contained the densest distribution of spinal cord-projecting vasopressin mRNA-expressing neurons. The magnocellular subdivisions displayed large numbers of vasopressin mRNA-expressing neurons, but very few of those projected to the spinal cord. The dorsal parvocellular subdivision contained a large number of spinally projecting neurons, but very few of those expressed vasopressin mRNA. These findings show that the PVH gives rise to a major vasopressinergic projection to the spinal cord and that the spinal cord-projecting vasopressinergic neurons are parceled into anatomically distinct cell groups. This provides an anatomical basis for a selective activation of functionally different groups in the PVH as part of a behaviorally adaptive response, including modulation of autonomic activity and pain processing at the spinal level.
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| 4. |
- Hallböök, Finn, et al.
(författare)
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Expression of neurotrophins and trk receptors in the avian retina
- 1996
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Ingår i: Journal of Comparative Neurology. - 0021-9967 .- 1096-9861. ; 364:4, s. 664-676
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Tidskriftsartikel (refereegranskat)abstract
- Using the RNase protection assay, we have found that nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3) are expressed in the avian retina during development. The expression peaks around embryonic days 12-15, with decreasing levels at later stages of development. Abundant levels of NGF and BDNF but low levels of NT-3 mRNA were found in the adult retina. We also found that light/darkness regulated the levels of NGF and BDNF mRNAs but not the levels of NT-3 mRNA in the 5-day-old chicken retina. It was demonstrated that NGF and BDNF mRNA levels were up-regulated by light exposure. The cellular localization of mRNA expression for the neurotrophins and neurotrophin receptors TrkA, TrkB, and TrkC in the retina was studied using in situ hybridization. The patterns of NGF and trkA mRNA expression were very similar and were localized to the external part of the inner nuclear layer on the border with the outer plexiform layer and corresponded to the localization of horizontal cells. NT-3 labeling was also found over the external part of the inner nuclear layer, whereas trkC mRNA was found over all layers in the retina. BDNF labeling was found over all layers in the retina, whereas TrkB labeling was intense over cells in the ganglion cell layer, which is in agreement with the response of ganglion cells to BDNF stimulation. Functional neurotrophin receptors were suggested by the response of retinal explants to neurotrophin stimulation. These data indicate that the neurotrophins play local roles in the retina that involve interactions between specific neuronal populations, which were identified by the localization of the Trk receptor expression. The data also suggest that NGF and BDNF expression is regulated by normal neuron usage in the retina.
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| 5. |
- Karlsson, Miriam, et al.
(författare)
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Nerve growth factor receptor TrkA is expressed by horizontal and amacrine cells during chicken retinal development
- 1998
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Ingår i: J. Comp. Neurol.. ; 400:3, s. 408-416
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Tidskriftsartikel (refereegranskat)abstract
- Nerve growth factor is known to stimulate neurite outgrowth and support neuronal survival during embryonic development. We have studied the expression of the nerve growth factor receptor, TrkA, at both mRNA and protein levels during the course of chicken retinal development. Furthermore, we have compared the expression of trkA mRNA with that of the 75-kD low-affinity neurotrophin receptor (p75NTR). RNase protection assay identified peak-levels of trkA mRNA in the late embryonic retina. Using in situ hybridization and immunohistochemistry, we found cells expressing TrkA in both the internal and the external part of the inner nuclear layer, corresponding to amacrine and horizontal cells, respectively. The TrkA-expressing amacrine cell has a unistratified dendritic arborization in the second sublamina of the inner plexiform layer, and may represent the stellate amacrine cell described by Cajal. The horizontal cells, possessing arciform dendrite processes in the outer plexiform layer, showed strong TrkA immunoreactivity in both dendrites and cell bodies. During the course of retinal development, the TrkA-expressing amacrine cells decreased in number, whereas the TrkA-expressing horizontal cells persisted. Because nerve growth factor was expressed where the horizontal cells, but not where the amacrine cells were located, these findings raise the question of whether nerve growth factor could locally support the survival of TrkA-expressing interneurons during retinal development.
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| 6. |
- Rice, Frank L, et al.
(författare)
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A comprehensive immunofluorescence and lectin binding analysis of vibrissal follicle sinus complex innervation in the mystacial pad of the rat
- 1997
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Ingår i: Journal of Comparative Neurology. - 0021-9967 .- 1096-9861. ; 385:2, s. 149-184
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Tidskriftsartikel (refereegranskat)abstract
- The innervation of the vibrissal follicle sinus complexes (FSCs) in the mystacial pad of the rat was examined by lectin binding histofluorescence with the B subunit of Griffonia simplicifolia (GSA) and by immunofluorescence with a wide variety of antibodies for neuronal related structural proteins, enzymes, and peptides. Only anti-protein gene product 9.5 labeled all sets of innervation. Several types of mechanoreceptors were distributed to specific different targets by medium to large caliber myelinated axons. All were positive for 200 kDa neurofilament subunit, peripherin, and carbonic anhydrase. Their endings expressed synaptophysin. Labeling for the 160 kDa neurofilament subunit, calbindin, and parvalbumin varied. Anti-Schwann cell protein S100 was completely co-extensive with the axons, terminal arbors, and endings of the mechanoreceptor afferents including Merkel innervation. At least 15 different sets of unmyelinated innervation were evident based upon distribution and labeling characteristics. They consisted of four basic types: 1) peptidergic; 2) GSA binding; 3) peptidergic and GSA binding; and 4) nonpeptidergic and GSA negative (peptide-/GSA-). Previous studies had not revealed that several major sets of unmyelinated innervation were peptide-/GSA-. The unmyelinated innervation had detectable peripherin but not 160 kDa or 200 kDa neurofilament subunits. GSA-positive axons uniquely lacked anti-S100 immunoreactivity. The dense circumferentially oriented unmyelinated innervation of the inner conical body contained major sets of peptide-/GSA- and GSA innervation as well as a smaller peptidergic GSA component. A small contingent of sympathetic and possibly parasympathetic innervation was affiliated with microvasculature in the FSCs. This study confirms and refutes some previous hypotheses about biochemical and morphological relationships between peripheral innervation and sensory ganglion cells.
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| 7. |
- von Euler, Mia, 1967-, et al.
(författare)
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Quantitative study of neurofilament-positive fiber length in rat spinal cord lesions using isotropic virtual planes
- 1998
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Ingår i: Journal of Comparative Neurology. - Philadelphia : John Wiley & Sons. - 0021-9967 .- 1096-9861. ; 400:4, s. 441-448
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Tidskriftsartikel (refereegranskat)abstract
- Spontaneous reocurrence of neurofilament (NF)-positive fibers has been described after spinal cord lesions in rats. However, previously introduced methods to evaluate the lesion and the regenerative fiber outgrowth suffer from several biases, why a new concept of quantitative, morphological analysis after spinal cord injury is needed. Length quantification of the putatively spontaneously regenerating fibers has been difficult until recently, when two length estimators based on sampling with isotropic virtual planes within thick physical sections were introduced. The applicability of these techniques to estimate the total length of NF-positive fibers was evaluated in photochemically induced ischemic lesions of thoracic spinal cords in young rats 6 weeks postlesion. Fiber length was found to be the most consistent measure with a mean of 3.71 m (coefficient of variation, CV = 0.16) in the 0.90 mm3 (CV = 0.26) large lesions. Whether or not the NF-positive fibers observed inside the lesion represent spontaneously regenerating axons needs to be confirmed in longitudinal, functional, and ultrastructural studies.
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| 8. |
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| 9. |
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| 10. |
- Dyakonova, Varvara, et al.
(författare)
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Anatomical basis for interactions of enkephalins with other transmitters in the CNS of a snail.
- 1995
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Ingår i: Journal of Comparative Neurology. - : Wiley. - 0021-9967 .- 1096-9861. ; 361, s. 38-47
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Tidskriftsartikel (refereegranskat)abstract
- Immunocytochemical techniques for double staining were employed to investigate the morphological basis for interactions between enkephalins and other neuroactive compounds in the behavior of the gastropod mollusc Cepaea nemoralis. Coexistence of each of the two enkephalins with FMRFamide, serotonin or GABA-like immunoreactivity was found in certain neurons in cerebral, parietal, and pedal ganglia. Tyrosine hydroxylase-immunoreactive neurons were occasionally seen in close apposition to, but never colocalized with, the enkephalins. A comparison between these anatomical observations and previous behavioral studies suggests that in gastropod molluscs cotransmission of enkephalins with classical transmitters may, at least partly, reflect synergism of these substances in the control of definite behavioral programs
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