- Email: [email protected]
Distribution of secretoneurin-like immunoreactivity in comparison with that of substance P in the human spinal cord
ELSEVIER
Neuroscience Letters
NEUROSCIENCE LmERS
191 (1995) 83-86
Distribution of secretoneurin-like immunoreactivity in comparison with that of substance P in the human spinal cord Stefan Telser, Josef Marksteiner, Hartmann Hinterhuber, Alois Saria* Neurochemical U n i t , D e p a r t m e n t o f P s y c h i a t r y , U n i v e r s i t y o f I n n s b r u c k ,
AnichstraJe
35, A-6020 Innsbruck, Austria
Received 10 March 1995; revised version received 13 April 1995; accepted 16 April 1995
Abstract
Secretoneurin (SN), a neuropeptide of 33 amino acids, was determined in comparison with substance P (SP) by immunocytochemistry in normal human spinal cord. The density of secretoneurin-like immunoreactivity (SN-IR) was high in the superficial dorsal horn and in the lateral column of autonomic arcs. The ventral horn displayed low to moderate density of SN-IR and prominently outlined motoneurons. The congruent distribution of SN and SP to the termination of primary afferents may indicate that SN is involved in modulation of pain. Keywords:
Secretogranin II; Secretoneurin; Immunocytochemistry; Human spinal cord
Secretoneurin (SN) derives from secretogranin II [7], a member of the chromogranin family [ 11. A distinct distribution of secretoneurin-like immunoreactivity (SN-IR) to the human and rat central nervous system is shown [l l131. In this study the pattern of SN-IR was determined in comparison w,ith that of substance P-like immunoreactivity (SP-IR) in normal human spinal cord as both peptides were found to be distributed to the terminal field of primary afferents in the rat [ 1 l]. Tissue was obtained from four adults of both sexes (30-83 years of age) within 24 h postmortem. Fixation [ 131, characterization of the antisera [ 10,12,13] and postmortem stability of SN [ 131 have been previously discussed. Free floating, consecutive, transverse sections of 8Opm were either processed for SN or SP following the procedures described in detail [13]. Controls without primary antisera and antisera preabsorbed with SN were included in each experiment. SN-IR mainly appeared as varicose fibers and dots of varying size. The most frequent type of fibers showed small round or oval varicosities and thin intervaricose segments (Fig. lDa/b). Fibers formed an interlacing network in lamina II, or were solely in the white matter adjacent to the lateral margin of the dorsal horn (Fig. 2Dl) and the lateral horn (Fig. 2C), or in the dorsal root (Fig. IDa). These fibers were also seen to be arranged in com* Corresponding author, Tel&ax:
+43 512 504 3710.
pact bundles (Fig. lE,F). Some structures, consisting of puncta circumposed on an immunonegative center forming a double-track immunoreactive pattern, were seen infrequently in the superficial dorsal horn and in relation to motoneurons (Fig. 1C). Only a low number of SN-IR perikarya was seen. Cell bodies, e.g. motoneurons (Fig. lC), outlined by immunoreactive puncta and fibers were frequently observed. In the dorsal horn SN-IR was most concentrated in Rexed’s lamina I and the inner lamina II which was constantly seen throughout the entire spinal cord (Fig. 2AH). The immunoreactive pattern of SN very closely corresponded to that of SP (Figs. lA,B; 2Dl,D2). Bundles of strongly immunopositive fibers passed at the medial and lateral margins of the superficial dorsal horn (Fig. 2D-F). Inner and outer Lamina II displayed an interlacing network of thin fibers. Varicose fibers could clearly be identified. Infrequently, some SN containing perikarya were seen in laminae I and II. Lamina III displayed a low density of immunoreactivity with single varicose fibers (Fig. 1Db). Single immunonegative perikarya were found outlined by puncta and fibers in lamina III and in the lateral portion of lamina I. The lateral reticulated region of lamina V showed low to moderate staining, increasing rostrocaudally (Fig. 2A-H). In the region of the intermediate gray matter, moderate SN-IR was identified around the central canal (lamina X)
0304-3940/95/$09.50 0 1995 Elsevier Science Ireland Ltd. All rights reserved SSDI 0304-3940(95)11566-C
S. Telser et al. I Neuroscience Letters 191 (1995) 83-86
Fig. 1. High power photomicrographs showing the distributional staining pattern of SN-PR (A) compared to that of SP-IR (B) in the superficial Pam&a6 of the dorsal horn in adjacent sections at lower thoracic level. Preferential distribution to inner lamina II (Iii) and lamina I (I), (A,B). Pericellular staining for SN-IR of a motoneuron at lumbar level (C). Dorsal root fiber (Da) (square in E) and small varicosities and intervaricose segments in SNpositive lamina III fiber (Db). Aspect of the dorsal part of a transversal section at lower sacral level stained for SN-IR (E). Bundles of fibers are crossing dorsally to the central canal (cc) from side to side forming strongly positive dorsal commissural fibers. Uniformly shaped sections of longitudinally running bundles of highly positive fibers in the lateral funiculus, especially in dorsolateral fasciculus (Lissauer’ s tract) (dlf) (arrow). High magnification of the same section (arrow in E) composed of densely packed, parallel fibers with rectangularly cut ends (F). 110, outer lamina II; III, X, Iamioae III and X. Scale bar is 100 pm in A, B, C, 20 pm in Da/b, F and 700 pm in E. increasing from lower thoracic to sacral levels (Fig. 2AH). The dorsal gray commissure displayed prominent staining (Figs. 1E; 2G). Thick bundles of fibers stained for SN extended across the dorsal lamina X towards the intermediolateral cell column (IML) (Fig. 1E; 2C). This was most obvious at thoracic levels. The thoracolumbar sympathetic and sacral parasympathetic nuclei displayed a high level of SN-IR. The pattern of SN-IR consisted of thin fibers and terminals. Immunopositive perikarya were not found. Some immunoreactive fibers extended laterally to the lateral funiculus at mid-thoracic levels (Fig. 2C,Dl, D2). Immunostaining for SP was found to be distributed to the same regions but less concentrated (Fig. 2,D2). Laminae VII and VIII of the ventral horn showed single fibers with varicosities of small diameter. Lamina IX, the sites of the motoneuronal perikarya, displayed low to moderate density of SN-IR. This was seen to increase from the thoracic to the sacral spinal cord (Fig. 2A-H). Pmmunoreactivity appeared as dots and varicose fibers. At lumbar levels, per?cellular-stained motoneurons were visualized (Fig. 1C). Onuf’s nucleus located in the lateral ventral horn at spinal levels (S2-S3) displayed moderate
immunostaining for SN as well as for SP (not shown). The staining pattern was mainly dots and sparse fibers and no perikaryal structures. Strongly SN-positive fibers were found in the lateral funiculus of the white matter. Some thin fibers passed in close vicinity to the lateral border of the dorsal horn (Fig. 2Dl) which displayed smail varicosities and small intervaricose segments at high magnification. Large marginal neurons located in the laterally surrounding white matter of the dorsal columns showed positive outlined perikarya for SN-IR and SP-IR (Fig. 2E-G). A great number of SN heavily immunostained, longitudinally oriented fibers were visualized particularly in the dorsolateral fasciculus (Lissauer’s tract) (Fig. 1E). High power magnification revealed uniformly shaped segments of thick bundles composed of parallel, thin fibers. The ends were found to be rectangularly cut to the direction of fibers (Fig. IF). At spinal levels below the cervical cord, positive fibers extended from the IML into the white matter (Fig. 2CI3). The dorsal roots entering the dorsal horns showed loose bundles of SN immunopositive fibers (Fig. 1Da). Our results on the laminar distribution of SP-IR are in good agreement with previous reports [2,15]. Qualita-
S. Telser et al. I Neuroscience Letters 191 (1995) 83-86
8.5
Fig. 2. Negative prints show distribution of SN (A to Dl to H) and SP (D2) to transverse sections at upper cervical level (A), cervicothoracic transition (B), mid-thoracic level (C-E), thoracolumbar transition (F), mid-lumbar (G) and lower sacral level (H). SN is most concentrated in superficial laminae of the dorsal horn (IJI), around the central canal (cc) and in the region of the intermediolateral cell column (iml) and sacral parasympathetic nuclei (spn). SN-IR fibers are changing sides in the dorsal gray commissum (dgc) (G) and are crossing between lamina X (x) and the intermediolateral region (iml) (C, arrowheads), some are radiating laterally into the lateral funiculus (If) (C, arrow, Dl,D2). Transversal fibers in the white matter in close vicinity to the lateral dorsal horn (DI, arrow). Pericellularly stained motoneurons at lumbar levels (G, arrowheads). Exemplary, overall comparison between SN-IR and SP-IR is given in DI and D2. Scale bars are I mm, same magnification in B-H.
86
S. Telser et al. /Neuroscience Letters 191 (‘1995)
tively, a very similar pattern of staining was obtained for SN-IR. The level of intensity of SN-IR was generally equal to that of SP-IR. Obviously, a higher density of SNIR was found in the IML, possibly due to a higher number of immunoreactive terminals and fibers. In some areas, the SN-IR pattern of staining might better be described as rather a functional than an anatomical, i.e. laminar distribution. SN-IR showed a continuous pathway of SN-involved interactions in the area of the dorsal horn, the IML and the central region (refer to Fig. 2C). The pattern of immunostaining for SN in human spinal cord in comparison to that in rat spinal cord [ 111 revealed high conformity in laminar distribution. In human, differences to rat were noted in lamina II where the inner portion displayed a higher density of SN-IR than the outer portion, which also matched well with the pattern found for SP-IR [ 151, and in a higher number of pericellularly stained neurons mainly in lamina IX. Neonatal capsaicin treatment in rat causes a markedly incomplete depletion of SN-IR [8] in the terminal field of primary afferents in the superficial laminae of the dorsal horn. Small, unmyelinated C-fiber neurons in dorsal root ganglia are shown to be capsaicin-sensitive [3,4,9]. As there is remaining immunoreactivity after capsaicin in rat, SN should derive from additional neuronal systems, as large, myelinated, capsaicin-insensitive cells in dorsal root ganglia, interneurons, and supraspinal sources [10,14]. A co-localization of SN with classical neurotransmitters in neurons of dorsal root ganglia is very likely, as SP and CGRP [6] are also affected by capsaicin treatment, and in situ hybridization gives evidence for synthesis of precursors of SN [8] and CGRP in the same neurons. In human, limb amputation causes an ipsilateral reduction of SP-IR in the superficial dorsal horn [5]. These arguments by analogy indicate that SN is functionally involved in neuronal systems which are related to its immunocytological appearance. The present study adds immunocytological evidence to possible, functional implications of SN. So far, it is most likely that SN is involved in the pain transmission pathway and the preganglionic autonomic system. The close immunocytological relation to motoneurons might also indicate a functional role of SN in the motor system. We thank Iris Berger for excellent technical assistance. This work was supported by the Austrian Science Foundation (Otto Loewi-Stipendium KOSl-Med, S F B F 00206). We thank Dr. R. Fischer-Colbrie, Department of Pharmacology, Innsbruck, for providing the SN-antiserum and Dr. H. Maier, Department of Pathology, Innsbruck, for the human postmortem tissue.
83-86
[!] Blaschko, II., Comline, R.S., Schneider, F.H., Silver, M. and Smith, A.D., Secretion of a cbromaffin granule protein, chromogranin, from the adrenal giand after splanchnic stimulation, Nature, 215 (1967) 58-59. [2] Cuello, A.C., Polak, J.M. and Pearse, A.G.E., Substance P: a naturally occurring transmitter in human spinal cord, Lance& 2 (1976) 1054-1056. f3] Holzer, P., Local effector functions of capsaicin-sensitive sensor; nerve endings: involvement of tachykinins, calcitonin generelated peptide and other neuropeptides, Neuroscience, 24 (19S8) 739-768. [4] Holzer, P., Capsaicin - cellular targets, mechanisms of action, and selectivity for thin sensory neurons, Pharmacol. Rev., 43 (1991) 143-201. [S] Hunt, S.P., Rossor, M.N. and Emson, P.C., Substance P and enkephalins in spinal cord after limb amputation, Lancet, 1 (1982) 1023. [6] Kashiba, H., Senba, E., Ueda, Y. and Tohyama, M., Relative sparing of calcitonin gene-related peptide-containing primary sensory neurons following neonatal capsaicin treatment in the rat, Peptides, 11 (1990) 491-496. [7] Kirchmair, R., Hogue-Angeletti, R., Gutierrez, I., Fischer-Colbrie, R. and Winkler, H., Secretoneurin - a neuropeptide generated in brain, adrenal medulla and other endocrine tissues by proteolytic processing of secretogranin II (chromogranin C), Neuroscience, 53 (1993) 359-366. [8] Kirchmair, R., Marksteiner, J., Troger, J., Mahata, S.K., Mahata, M., Donnerer, J., Amann, R., Fischer-Colbrie, R., Winkler, Ii. and Saria, A., Human and rat primary C-fibre afferents store and release secretoneurin, a novel neuropeptide, Eur. J. Neurosci., 6 (1994) 861-868. [9] Maggi, C.A. and Meli, A., The sensory-efferent function of capsaicin-sensitive sensory neurons, Gen. Pharmacol., 19 (1988) l-43. [lo] Marksteiner, J., Kirchmair, R., Mahata, S.K., Mabata, M., Fischer-Colbrie. R., Hogue-Angeletti, R., Saria: A. and Winkler, H., Distribution of secretoneurin, a peptide derived from secretogranin II, in rat brain. An immunocytocbemical and radioimmunological study, Neuroscience, 54 (1993) 923-944. El l] Marksteiner, J., Mahata, S.K., Pycha, R., Mahata, M., Saria, A., Fischer-Colbrie, R. and Winkler, II., Distribution of secretoneurin~ immunoreactivity in the spinal cord and lower brainstem in comparison with that of substance P and calcitonin gene-related peptide, J. Comp. Neurol., 340 (1994) 243-254. j12] Marksteiner, J., Saria, A. and Hinterhuber, II., Distribution of secretoneurin-immunoreactivity in comparison with that of substance P in human brain stem, J. Chem. Neuroanat., 7 (1994) 253270. [13] Marksteiner, J., Saria, A., Kirchmair, R., Pycha, R., Benesch, II., Fischer-Colbrie, R., Haring, C., Maier, H. and Ransmayr, G., Distribution of secretoneurin- in comparison with substance Pand enkephalin-like immunoreactivities in various human forebrain regions, Eur. .I. Neurosci., 5 (1993) 1573-1585. 1141 Menetrey, D. and Basbaum, A.I., Spinal and trigeminal projections to the nucleus of the solitary tract: a possible substrate for somatovisceral and viscerovisceral reflex activation, J. Comp. Neurol., 255 (1987) 439-450. [15] Schoenen, J. and Faull, R.L.M., Spinal cord: chemoarchitectural organization. In G. Paxinos (Ed.), The Human Nervous System, Academic Press, San Diego, CA, 1990, pp. 55-76.
Neuroscience Letters
NEUROSCIENCE LmERS
191 (1995) 83-86
Distribution of secretoneurin-like immunoreactivity in comparison with that of substance P in the human spinal cord Stefan Telser, Josef Marksteiner, Hartmann Hinterhuber, Alois Saria* Neurochemical U n i t , D e p a r t m e n t o f P s y c h i a t r y , U n i v e r s i t y o f I n n s b r u c k ,
AnichstraJe
35, A-6020 Innsbruck, Austria
Received 10 March 1995; revised version received 13 April 1995; accepted 16 April 1995
Abstract
Secretoneurin (SN), a neuropeptide of 33 amino acids, was determined in comparison with substance P (SP) by immunocytochemistry in normal human spinal cord. The density of secretoneurin-like immunoreactivity (SN-IR) was high in the superficial dorsal horn and in the lateral column of autonomic arcs. The ventral horn displayed low to moderate density of SN-IR and prominently outlined motoneurons. The congruent distribution of SN and SP to the termination of primary afferents may indicate that SN is involved in modulation of pain. Keywords:
Secretogranin II; Secretoneurin; Immunocytochemistry; Human spinal cord
Secretoneurin (SN) derives from secretogranin II [7], a member of the chromogranin family [ 11. A distinct distribution of secretoneurin-like immunoreactivity (SN-IR) to the human and rat central nervous system is shown [l l131. In this study the pattern of SN-IR was determined in comparison w,ith that of substance P-like immunoreactivity (SP-IR) in normal human spinal cord as both peptides were found to be distributed to the terminal field of primary afferents in the rat [ 1 l]. Tissue was obtained from four adults of both sexes (30-83 years of age) within 24 h postmortem. Fixation [ 131, characterization of the antisera [ 10,12,13] and postmortem stability of SN [ 131 have been previously discussed. Free floating, consecutive, transverse sections of 8Opm were either processed for SN or SP following the procedures described in detail [13]. Controls without primary antisera and antisera preabsorbed with SN were included in each experiment. SN-IR mainly appeared as varicose fibers and dots of varying size. The most frequent type of fibers showed small round or oval varicosities and thin intervaricose segments (Fig. lDa/b). Fibers formed an interlacing network in lamina II, or were solely in the white matter adjacent to the lateral margin of the dorsal horn (Fig. 2Dl) and the lateral horn (Fig. 2C), or in the dorsal root (Fig. IDa). These fibers were also seen to be arranged in com* Corresponding author, Tel&ax:
+43 512 504 3710.
pact bundles (Fig. lE,F). Some structures, consisting of puncta circumposed on an immunonegative center forming a double-track immunoreactive pattern, were seen infrequently in the superficial dorsal horn and in relation to motoneurons (Fig. 1C). Only a low number of SN-IR perikarya was seen. Cell bodies, e.g. motoneurons (Fig. lC), outlined by immunoreactive puncta and fibers were frequently observed. In the dorsal horn SN-IR was most concentrated in Rexed’s lamina I and the inner lamina II which was constantly seen throughout the entire spinal cord (Fig. 2AH). The immunoreactive pattern of SN very closely corresponded to that of SP (Figs. lA,B; 2Dl,D2). Bundles of strongly immunopositive fibers passed at the medial and lateral margins of the superficial dorsal horn (Fig. 2D-F). Inner and outer Lamina II displayed an interlacing network of thin fibers. Varicose fibers could clearly be identified. Infrequently, some SN containing perikarya were seen in laminae I and II. Lamina III displayed a low density of immunoreactivity with single varicose fibers (Fig. 1Db). Single immunonegative perikarya were found outlined by puncta and fibers in lamina III and in the lateral portion of lamina I. The lateral reticulated region of lamina V showed low to moderate staining, increasing rostrocaudally (Fig. 2A-H). In the region of the intermediate gray matter, moderate SN-IR was identified around the central canal (lamina X)
0304-3940/95/$09.50 0 1995 Elsevier Science Ireland Ltd. All rights reserved SSDI 0304-3940(95)11566-C
S. Telser et al. I Neuroscience Letters 191 (1995) 83-86
Fig. 1. High power photomicrographs showing the distributional staining pattern of SN-PR (A) compared to that of SP-IR (B) in the superficial Pam&a6 of the dorsal horn in adjacent sections at lower thoracic level. Preferential distribution to inner lamina II (Iii) and lamina I (I), (A,B). Pericellular staining for SN-IR of a motoneuron at lumbar level (C). Dorsal root fiber (Da) (square in E) and small varicosities and intervaricose segments in SNpositive lamina III fiber (Db). Aspect of the dorsal part of a transversal section at lower sacral level stained for SN-IR (E). Bundles of fibers are crossing dorsally to the central canal (cc) from side to side forming strongly positive dorsal commissural fibers. Uniformly shaped sections of longitudinally running bundles of highly positive fibers in the lateral funiculus, especially in dorsolateral fasciculus (Lissauer’ s tract) (dlf) (arrow). High magnification of the same section (arrow in E) composed of densely packed, parallel fibers with rectangularly cut ends (F). 110, outer lamina II; III, X, Iamioae III and X. Scale bar is 100 pm in A, B, C, 20 pm in Da/b, F and 700 pm in E. increasing from lower thoracic to sacral levels (Fig. 2AH). The dorsal gray commissure displayed prominent staining (Figs. 1E; 2G). Thick bundles of fibers stained for SN extended across the dorsal lamina X towards the intermediolateral cell column (IML) (Fig. 1E; 2C). This was most obvious at thoracic levels. The thoracolumbar sympathetic and sacral parasympathetic nuclei displayed a high level of SN-IR. The pattern of SN-IR consisted of thin fibers and terminals. Immunopositive perikarya were not found. Some immunoreactive fibers extended laterally to the lateral funiculus at mid-thoracic levels (Fig. 2C,Dl, D2). Immunostaining for SP was found to be distributed to the same regions but less concentrated (Fig. 2,D2). Laminae VII and VIII of the ventral horn showed single fibers with varicosities of small diameter. Lamina IX, the sites of the motoneuronal perikarya, displayed low to moderate density of SN-IR. This was seen to increase from the thoracic to the sacral spinal cord (Fig. 2A-H). Pmmunoreactivity appeared as dots and varicose fibers. At lumbar levels, per?cellular-stained motoneurons were visualized (Fig. 1C). Onuf’s nucleus located in the lateral ventral horn at spinal levels (S2-S3) displayed moderate
immunostaining for SN as well as for SP (not shown). The staining pattern was mainly dots and sparse fibers and no perikaryal structures. Strongly SN-positive fibers were found in the lateral funiculus of the white matter. Some thin fibers passed in close vicinity to the lateral border of the dorsal horn (Fig. 2Dl) which displayed smail varicosities and small intervaricose segments at high magnification. Large marginal neurons located in the laterally surrounding white matter of the dorsal columns showed positive outlined perikarya for SN-IR and SP-IR (Fig. 2E-G). A great number of SN heavily immunostained, longitudinally oriented fibers were visualized particularly in the dorsolateral fasciculus (Lissauer’s tract) (Fig. 1E). High power magnification revealed uniformly shaped segments of thick bundles composed of parallel, thin fibers. The ends were found to be rectangularly cut to the direction of fibers (Fig. IF). At spinal levels below the cervical cord, positive fibers extended from the IML into the white matter (Fig. 2CI3). The dorsal roots entering the dorsal horns showed loose bundles of SN immunopositive fibers (Fig. 1Da). Our results on the laminar distribution of SP-IR are in good agreement with previous reports [2,15]. Qualita-
S. Telser et al. I Neuroscience Letters 191 (1995) 83-86
8.5
Fig. 2. Negative prints show distribution of SN (A to Dl to H) and SP (D2) to transverse sections at upper cervical level (A), cervicothoracic transition (B), mid-thoracic level (C-E), thoracolumbar transition (F), mid-lumbar (G) and lower sacral level (H). SN is most concentrated in superficial laminae of the dorsal horn (IJI), around the central canal (cc) and in the region of the intermediolateral cell column (iml) and sacral parasympathetic nuclei (spn). SN-IR fibers are changing sides in the dorsal gray commissum (dgc) (G) and are crossing between lamina X (x) and the intermediolateral region (iml) (C, arrowheads), some are radiating laterally into the lateral funiculus (If) (C, arrow, Dl,D2). Transversal fibers in the white matter in close vicinity to the lateral dorsal horn (DI, arrow). Pericellularly stained motoneurons at lumbar levels (G, arrowheads). Exemplary, overall comparison between SN-IR and SP-IR is given in DI and D2. Scale bars are I mm, same magnification in B-H.
86
S. Telser et al. /Neuroscience Letters 191 (‘1995)
tively, a very similar pattern of staining was obtained for SN-IR. The level of intensity of SN-IR was generally equal to that of SP-IR. Obviously, a higher density of SNIR was found in the IML, possibly due to a higher number of immunoreactive terminals and fibers. In some areas, the SN-IR pattern of staining might better be described as rather a functional than an anatomical, i.e. laminar distribution. SN-IR showed a continuous pathway of SN-involved interactions in the area of the dorsal horn, the IML and the central region (refer to Fig. 2C). The pattern of immunostaining for SN in human spinal cord in comparison to that in rat spinal cord [ 111 revealed high conformity in laminar distribution. In human, differences to rat were noted in lamina II where the inner portion displayed a higher density of SN-IR than the outer portion, which also matched well with the pattern found for SP-IR [ 151, and in a higher number of pericellularly stained neurons mainly in lamina IX. Neonatal capsaicin treatment in rat causes a markedly incomplete depletion of SN-IR [8] in the terminal field of primary afferents in the superficial laminae of the dorsal horn. Small, unmyelinated C-fiber neurons in dorsal root ganglia are shown to be capsaicin-sensitive [3,4,9]. As there is remaining immunoreactivity after capsaicin in rat, SN should derive from additional neuronal systems, as large, myelinated, capsaicin-insensitive cells in dorsal root ganglia, interneurons, and supraspinal sources [10,14]. A co-localization of SN with classical neurotransmitters in neurons of dorsal root ganglia is very likely, as SP and CGRP [6] are also affected by capsaicin treatment, and in situ hybridization gives evidence for synthesis of precursors of SN [8] and CGRP in the same neurons. In human, limb amputation causes an ipsilateral reduction of SP-IR in the superficial dorsal horn [5]. These arguments by analogy indicate that SN is functionally involved in neuronal systems which are related to its immunocytological appearance. The present study adds immunocytological evidence to possible, functional implications of SN. So far, it is most likely that SN is involved in the pain transmission pathway and the preganglionic autonomic system. The close immunocytological relation to motoneurons might also indicate a functional role of SN in the motor system. We thank Iris Berger for excellent technical assistance. This work was supported by the Austrian Science Foundation (Otto Loewi-Stipendium KOSl-Med, S F B F 00206). We thank Dr. R. Fischer-Colbrie, Department of Pharmacology, Innsbruck, for providing the SN-antiserum and Dr. H. Maier, Department of Pathology, Innsbruck, for the human postmortem tissue.
83-86
[!] Blaschko, II., Comline, R.S., Schneider, F.H., Silver, M. and Smith, A.D., Secretion of a cbromaffin granule protein, chromogranin, from the adrenal giand after splanchnic stimulation, Nature, 215 (1967) 58-59. [2] Cuello, A.C., Polak, J.M. and Pearse, A.G.E., Substance P: a naturally occurring transmitter in human spinal cord, Lance& 2 (1976) 1054-1056. f3] Holzer, P., Local effector functions of capsaicin-sensitive sensor; nerve endings: involvement of tachykinins, calcitonin generelated peptide and other neuropeptides, Neuroscience, 24 (19S8) 739-768. [4] Holzer, P., Capsaicin - cellular targets, mechanisms of action, and selectivity for thin sensory neurons, Pharmacol. Rev., 43 (1991) 143-201. [S] Hunt, S.P., Rossor, M.N. and Emson, P.C., Substance P and enkephalins in spinal cord after limb amputation, Lancet, 1 (1982) 1023. [6] Kashiba, H., Senba, E., Ueda, Y. and Tohyama, M., Relative sparing of calcitonin gene-related peptide-containing primary sensory neurons following neonatal capsaicin treatment in the rat, Peptides, 11 (1990) 491-496. [7] Kirchmair, R., Hogue-Angeletti, R., Gutierrez, I., Fischer-Colbrie, R. and Winkler, H., Secretoneurin - a neuropeptide generated in brain, adrenal medulla and other endocrine tissues by proteolytic processing of secretogranin II (chromogranin C), Neuroscience, 53 (1993) 359-366. [8] Kirchmair, R., Marksteiner, J., Troger, J., Mahata, S.K., Mahata, M., Donnerer, J., Amann, R., Fischer-Colbrie, R., Winkler, Ii. and Saria, A., Human and rat primary C-fibre afferents store and release secretoneurin, a novel neuropeptide, Eur. J. Neurosci., 6 (1994) 861-868. [9] Maggi, C.A. and Meli, A., The sensory-efferent function of capsaicin-sensitive sensory neurons, Gen. Pharmacol., 19 (1988) l-43. [lo] Marksteiner, J., Kirchmair, R., Mahata, S.K., Mabata, M., Fischer-Colbrie. R., Hogue-Angeletti, R., Saria: A. and Winkler, H., Distribution of secretoneurin, a peptide derived from secretogranin II, in rat brain. An immunocytocbemical and radioimmunological study, Neuroscience, 54 (1993) 923-944. El l] Marksteiner, J., Mahata, S.K., Pycha, R., Mahata, M., Saria, A., Fischer-Colbrie, R. and Winkler, II., Distribution of secretoneurin~ immunoreactivity in the spinal cord and lower brainstem in comparison with that of substance P and calcitonin gene-related peptide, J. Comp. Neurol., 340 (1994) 243-254. j12] Marksteiner, J., Saria, A. and Hinterhuber, II., Distribution of secretoneurin-immunoreactivity in comparison with that of substance P in human brain stem, J. Chem. Neuroanat., 7 (1994) 253270. [13] Marksteiner, J., Saria, A., Kirchmair, R., Pycha, R., Benesch, II., Fischer-Colbrie, R., Haring, C., Maier, H. and Ransmayr, G., Distribution of secretoneurin- in comparison with substance Pand enkephalin-like immunoreactivities in various human forebrain regions, Eur. .I. Neurosci., 5 (1993) 1573-1585. 1141 Menetrey, D. and Basbaum, A.I., Spinal and trigeminal projections to the nucleus of the solitary tract: a possible substrate for somatovisceral and viscerovisceral reflex activation, J. Comp. Neurol., 255 (1987) 439-450. [15] Schoenen, J. and Faull, R.L.M., Spinal cord: chemoarchitectural organization. In G. Paxinos (Ed.), The Human Nervous System, Academic Press, San Diego, CA, 1990, pp. 55-76.