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Zhong SB, Zhang DY, Li HB, Yao JX. Identification of Haynaldia villosa chromosomes added to wheat using a sequential C-banding and genomic in situ hybridization technique. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 1996; 92:116-120. [PMID: 24166125 DOI: 10.1007/bf00222960] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/1995] [Accepted: 06/23/1995] [Indexed: 06/02/2023]
Abstract
Genomic in situ hybridization (GISH) offers a convenient and effective method for cytological detection, but can not determine the identity of the chromosomes involved. We integrated C-banding with GISH to identify Haynaldia villosa chromosomes in a wheat background. All chromosomes of H. villosa showed C-bands, either in telomeric regions or in both telomeric and centromeric regions, which allowed unequivocal identification of each H. villosa chromosome. The seven pairs of H. villosa chromosomes were differentiated as 1-7 according to their characteristic C-bands. Using a sequential C-banding and GISH technique, we have analyzed somatic cells of F3 plants from the amphiploid Triticum aestivum-H. villosa x 'Yangmai 158' hybrids. Three plants (94009/5-4,94009/5-8 and 94009/5-9) were shown to contain H. villosa chromosome(s). 94009/5-4 (2n = 45) had three H. villosa chromosomes (2, 3 and 4); 94009/5-8 (2n = 45) possessed one chromosome 4 and a pair of chromosome 5, and 94009/5-9 (2n = 43) was found to have one chromosome 6 of H. villosa. The combination of GISH with C-banding described here provides a direct comparison of the cytological and molecular landmarks. Such a technique is particularly useful for identifying and localizing alien chromatin and DNA sequences in plants.
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252
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Ni JW, Matsumoto K, Li HB, Murakami Y, Watanabe H. Neuronal damage and decrease of central acetylcholine level following permanent occlusion of bilateral common carotid arteries in rat. Brain Res 1995; 673:290-6. [PMID: 7606443 DOI: 10.1016/0006-8993(94)01436-l] [Citation(s) in RCA: 124] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The neuronal damages and the changes in central acetylcholine (ACh) and choline (Ch) contents following permanent occlusion of bilateral common carotid arteries (2VO) of rats were investigated 1 and 4 months after the operation. Two types of neuronal damages were observed in the rats with permanent 2VO. The first type was the infarctions observed in the cerebral cortex and striatum. The infarction in the cortex and striatum was observed in 28.6 and 42.9% of the animals examined 1 month after permanent 2VO, respectively. These ratios did not change even when examined 4 months after permanent 2VO, suggesting that this type of neuronal damage is due to acute ischemic attacks. The second type was progressive neuronal damages observed in the hippocampus and white matter: the neuronal loss in the CA1 subfield appeared 4 months but not 1 month after permanent 2VO and the rarefaction of white matter which was observed 1 months after permanent 2VO and markedly increased 4 months after the operation. Moreover, ACh level significantly decreased in the striatum but not in the cortex, hippocampus or hypothalamus 1 month after permanent 2VO, while the ACh levels in the cortex, striatum and hypothalamus, and Ch levels in all the regions tested significantly decreased when tested 4 months after the operation. These changes did not accompany necrosis. These results suggest that the progressive neuronal degeneration and cholinergic dysfunction following the permanent 2VO are in part involved in chronic cerebral hypoperfusion-induced long-lasting cognition deficits in rats.
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253
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Guan ZJ, Liu ZQ, Li HB. [The immunoactive cells in lesions of oral lichen planus]. SHANGHAI KOU QIANG YI XUE = SHANGHAI JOURNAL OF STOMATOLOGY 1995; 4:43-5. [PMID: 15160111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
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254
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Hedberg MH, Johansson AM, Nordvall G, Yliniemelä A, Li HB, Martin AR, Hjorth S, Unelius L, Sundell S, Hacksell U. (R)-11-hydroxy- and (R)-11-hydroxy-10-methylaporphine: synthesis, pharmacology, and modeling of D2A and 5-HT1A receptor interactions. J Med Chem 1995; 38:647-58. [PMID: 7861413 DOI: 10.1021/jm00004a011] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
(R)-11-Hydroxyaporphine (2) and (R)-11-hydroxy-10-methylaporphine (3) were synthesized from natural morphine by using new, short, and efficient synthetic sequences. The dopaminergic and serotonergic effects of 2 and 3 were evaluated by use of in vitro and in vivo test systems. The results indicate that 3 is a potent, selective, and efficacious 5-HT1A receptor agonist. In contrast, 2 is a partial 5-HT1A receptor agonist of low potency which has affinity also for central D1 and D2A receptors. The differences in pharmacological profiles were rationalized by modeling of ligand-receptor interactions using homology-based receptor models of the 5-HT1A and D2A receptor binding site. The selective and pronounced serotonergic effects of 3 appear to be due to the C10-methyl group, which is accommodated by a lipophilic pocket in the 5-HT1A receptor. In contrast, the C10-methyl group of 3 is not accommodated by the binding site model of the D2A receptor.
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255
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Agarwal A, Pearson PP, Taylor EW, Li HB, Dahlgren T, Herslöf M, Yang Y, Lambert G, Nelson DL, Regan JW. Three-dimensional quantitative structure-activity relationships of 5-HT receptor binding data for tetrahydropyridinylindole derivatives: a comparison of the Hansch and CoMFA methods. J Med Chem 1993; 36:4006-14. [PMID: 8258822 DOI: 10.1021/jm00077a003] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A series of new derivatives of 3-(1,2,5,6-tetrahydropyridin-4-yl)indole (4-THPI) has been synthesized, and their dissociation constants at the 5-HT1A and 5-HT2 serotonin (5-HT) receptor subtypes have been determined. The new data were combined with similar binding data on a related set of THPI analogs reported previously (Taylor et al. Mol. Pharmacol. 1988, 34, 42-53) and used to develop 3-dimensional quantitative structure-activity relationships (3-D QSARs) for these compounds at the 5-HT1A and 5-HT2 receptor sites, by the method of comparative molecular field analysis (CoMFA). Since the previous study included several conventional QSARs obtained by Hansch analysis, and the new compounds in some cases fall within the congeneric series used in those analyses, we were able to make a direct comparison of the predictive capabilities of CoMFA and Hansch analysis using identical training and test data sets. The overall quality of actual predictions of activity by both methods appears to be about the same, as assessed by the root mean square (rms) residuals between actual and predicted pKi values. On the one hand, the compounds most poorly predicted by the Hansch analysis were 34, 35, and 37, while compounds 30-33 were relative poorly predicted by CoMFA. However, a clear advantage of CoMFA is the ability to include diversely substituted or noncongeneric analogs that must be omitted from conventional QSAR analysis. Using the entire data set of 45 THPI analogs reported here, pKi predictions for six additional compounds having 5-heteroarylindole substituents gave rms residuals of 0.46 and 0.36 for the 5-HT1A and 5-HT2 models, respectively; this is close to the experimental error of the binding data. The significance of the CoMFA field graphs in terms of molecular features required for activity and selectivity at these 5-HT receptor subtypes is discussed.
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256
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Li HB. [Report of food poisoning by Salmonella hadar in China]. ZHONGHUA YU FANG YI XUE ZA ZHI [CHINESE JOURNAL OF PREVENTIVE MEDICINE] 1993; 27:139-40. [PMID: 8243173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A food poisoning epidemic caused by Salmonella hadar was confirmed by epidemiologic investigation and laboratory examination Samonalle hadar had been detected in the specimens of food feces of patients. Many epidemics of food poisoning caused by Salmonall group of have been reported before, but that caused by the serogroup Hadar hereby reported organisms is the first of its hind in China. Attention should be paid by the public health authorities.
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257
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Li HB, Liu LS. Endothelium-derived nitric oxide: role in vascular regulation and interaction with norepinephrine, endothelin and superoxide anion. Chin Med J (Engl) 1993; 106:258-65. [PMID: 8391968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Endothelium-derived nitric oxide (EDNO) is an important vasodilator substance produced by the vascular endothelium. The present in vivo and in vitro study is aimed at evaluating its role in vascular regulation and its interactions with norepinephrine (NE), endothelin-1 (ET) and superoxide anion. In male anesthetized wistar rats, inhibition of the in vivo EDNO pathway with L-NAME (an established specific inhibitor of EDNO synthesis, 1-4 (mg/kg, iv bolus) provoked sustained, dose-dependent hypertensive responses (mean arterial pressure increased 45 +/- 1.5% over baseline for more than 60 minutes at a dose of 4 mg/kg, mean +/- Sx, which was completely reversed by L-arginine, the normal substrate for EDNO synthesis). In the in vitro study on rat aortic rings, blocking the endothelial production of EDNO with L-NAME (10(-4) M), caused the most prominent enhancement of the contractile responses to NE (increased maximal responses and lowered EC50), a smaller enhancement of contraction to ET and minimal modification of the vasoconstrictive effects of superoxide anion. L-arginine (10(-4) M), on the contrary, slightly attenuated the contraction to NE and ET but without the contraction to superoxide anion. The present study confirms that EDNO system represents one of the most important physiological depressor mechanisms in vivo, and indicates that EDNO is an important, differential antagonistic mechanism against the vasoconstrictors. It is also demonstrated that L-arginine availability is generally not the rate-limiting step in the in vivo generation of EDNO. The implications of the results were discussed.
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258
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Zhao HY, Li HB, Wang L, Zheng XH, Wu H. Experiences in intravenous urokinase treatment of 100 acute myocardial infarction patients. JOURNAL OF TONGJI MEDICAL UNIVERSITY = TONG JI YI KE DA XUE XUE BAO 1991; 11:159-64. [PMID: 1784045 DOI: 10.1007/bf02888128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
From 1980 to 1990 we treated 100 cases of AMI with i.v. urokinase (UK). According to the way of management and the dosage administered all these cases were divided into three groups: first stage of small dosage, second stage of trial big dosage, and third stage of comprehensive dosage. 36 patients of the first stage were treated with small dosage, 1-20,000 U b.i.d. for 1 week. 75% of the UK-treated and only 17% of the control group obtained relief of pain. Decrease of elevated ST reaching base line was 50 vs 8%, and FDP increased in 94%. 22 patients of the second stage were undergoing trial of big dosage. They were subdivided into larger dosage (more than 800,000 U) and smaller dosage (less than 300,000 U) groups. From the larger dosage group, 2 patients showed definite sign of recanalization, but unexpectedly 2 patients died of cardiac rupture. Since the recanalization rate of larger dosage group was 42.9%, but no case showed sign of recanalization in smaller dosage group, we are of the opinion that the dose of 800,000 U is rational for patients with symptoms' onset less than 3 h. Cardiac rupture was thought to be mostly due to reperfusion injury. Thus we designed the third stage of comprehensive dosage of UK. In this stage we used different dosage of UK and different ways of administration in 52 patients, based on the different symptoms' onset, so as to bring the effect of UK in full play. The aim of using UK is chiefly fibrinolysis as well as improvement of blood viscosity.(ABSTRACT TRUNCATED AT 250 WORDS)
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259
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Watt CB, Glazebrook PA, Li HB. Coexistence of somatostatin and neurotensin in amacrine cells of the chicken retina. Brain Res 1991; 546:166-70. [PMID: 1677304 DOI: 10.1016/0006-8993(91)91174-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A comparison of previous immunocytochemical studies reveals a striking similarity in the morphologies of the populations of somatostatin-like and neurotensin-like immunoreactive amacrine cells in the chicken retina. A double-label analysis was performed to determine if these two neuroactive peptides coexist in chicken amacrine cells. An examination of retinal cryosections collected throughout the retina revealed that all labelled cells express both somatostatin- and neurotensin-like immunoreactivity. Therefore, these results indicate the presence of a single population of chicken amacrine cells whose members contain both of these neuroactive peptides.
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260
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Li HB, Watt CB, Lam DM. Double-label analyses of somatostatin's coexistence with enkephalin and gamma-aminobutyric acid in amacrine cells of the chicken retina. Brain Res 1990; 525:304-9. [PMID: 1979235 DOI: 10.1016/0006-8993(90)90879-g] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Double-label analyses were performed to investigate somatostatin's coexistence with either enkephalin or gamma-aminobutyric acid (GABA) in amacrine cells of the chicken retina. Double-label immunocytochemistry revealed that although some amacrine cells labelled only for somatostatin or enkephalin, approx. 81% and 85% of somatostatin-immunopositive cells in the center and periphery of the retina, respectively, were also enkephalin-immunoreactive. Somatostatin-immunocytochemistry combined with autoradiography of high-affinity [3H]GABA uptake revealed that approx. 18% of somatostatin-immunoreactive amacrine cells exhibit high-affinity uptake of [3H]GABA.
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261
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Abstract
Light microscopic immunocytochemistry was utilized to localize populations of neurons in the human retina immunoreactive for the following neuroactive peptides: substance P (SP), vasoactive intestinal polypeptide (VIP), somatostatin (SOM) and LANT-6-(H-Lys-Asn-Pro-Tyr-Ile-Leu-OH), a hexapeptide which is identical to the C-terminal half of neurotensin except for the amino acid substitutions Lys/Arg and Asn/Arg. The majority of SP immunoreactive cells were amacrine cells whose pear-shaped or oval cell bodies (about 8 microns in diameter) were situated in the proximal parts of the inner nuclear layer. A small number of SP-stained somas (about 10-15 microns in diameter) were located in the ganglion cell layer and were designated as those of displaced amacrine cells. The SP-immunoreactive processes were distributed in sublamina 1, 3 and 5 with the most dense plexus being found in sublamina 3 of the inner layer. VIP-positive cell bodies (8-9 microns) were oval or pear-shaped and were situated in the innermost cell rows of inner nuclear layer. The majority of fine VIP-immunoreactive processes extended to sublamina 3 with only a few branches distributing in sublamina 1 of the inner plexiform layer. The SOM-stained cell bodies (10-11 microns) were round and were situated in the innermost cell rows of inner nuclear layer. SOM-positive processes were observed in sublamina 1 and 2 of the inner plexiform layer. The LANT-6 immunoreactive cell bodies (12-22 microns) were either oval-, round- or pyriform-shaped and were situated in ganglion cell layer.(ABSTRACT TRUNCATED AT 250 WORDS)
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262
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Li HB, Lam DM. Synaptic organization of neurotensin immunoreactive amacrine cells in the chicken retina. J Comp Neurol 1990; 294:252-61. [PMID: 2332531 DOI: 10.1002/cne.902940209] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Immunohistochemistry was utilized to investigate the light and electron microscopic localization of neurotensinlike immunoreactive (NT) amacrine cells in the chicken retina. The NT cells possess oval cell bodies (7 microns in diameter) that are located in either the second or third tier of cells from the border of the inner nuclear and inner plexiform layers. The processes of such cells extend into the inner plexiform layer where they ramify as a narrow plexus in sublamina 1 and as a broad plexus in sublaminas 3 and 4. Additionally, stained processes are observed occasionally within sublamina 5. At the ultrastructural level, NT-positive somas exhibit a rather dense and evenly distributed peroxidase reaction product throughout their cytoplasm. The nucleus of NT amacrine cells possess a round, unindented nuclear membrane. NT-immunoreactive processes in the inner plexiform layer interact synaptically only with non-NT cells. NT processes receive synaptic input mainly from the processes of amacrine cells and to a lesser degree from bipolar cells. The large majority of NT-stained varicosities form presynaptic contacts onto the processes of amacrine cells, but are also presynaptic to bipolar cell axon terminals. Moreover, each of the above synaptic relationships can be identified in each of sublaminas 1 and 3 to 4 of the inner plexiform layer. In addition, NT processes are presynaptic to processes devoid of synaptic vesicles that may originate from ganglion cells. Finally, NT processes occasionally form synaptic contacts onto somas situated in the most proximal row of the inner nuclear layer.
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263
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Eldred WD, Li HB, Carraway RE, Dowling JE. Immunocytochemical localization of LANT-6-like immunoreactivity within neurons in the inner nuclear and ganglion cell layers in vertebrate retinas. Brain Res 1987; 424:361-70. [PMID: 3499963 DOI: 10.1016/0006-8993(87)91481-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
LANT-6 is a hexapeptide (H-Lys-Asn-Pro-Tyr-Ile-Leu-OH) isolated from chicken small intestine, which resembles the COOH-terminal half of neurotensin, except for the amino acid substitutions Lys/Arg and Asn/Arg. The present report concerns the immunocytochemical staining of vertebrate retinas using an antiserum directed against LANT-6. In the retinas from goldfish, bird and turtle, cells in both the inner nuclear and ganglion cell layers were labeled, but in the frog no cells were labeled specifically and in the rat only cells in the ganglion cell layer were labeled. Labeled cell bodies in the inner nuclear layer gave rise to processes which were seen primarily within the following laminas of the inner plexiform layer (IPL): in the goldfish, lamina 3; chicken, laminae 1, 3 and 4; and turtle, laminae 3, 4 and 5. The cell bodies of the labeled neurons in the ganglion cell layer gave rise to dendrites which entered the IPL and axons which descended to the optic fiber layer. The cells with LANT-6-like immunoreactivity were distributed in both the central and peripheral parts of the retina in all the species examined except frog. Measured by radioimmunoassays, the levels of LANT-6-like-immunoreactivity in extracts of turtle, chicken, and goldfish retinas were 5-30 times those for neurotensin-like immunoreactivity, however no LANT-6-like immunoreactivity was detected in frog. Multiple chromatographic analyses indicated that while the LANT-6-like immunoreactivity in chicken retina was indistinguishable from synthetic LANT-6, LANT-6-like immunoreactivity in turtle and goldfish retinas was primarily associated with large molecular forms. Treatment of turtle LANT-6-like immunoreactivity with pepsin, an enzyme known to mimic processing for neurotensin precursors, yielded 3 major peptides, one of which co-chromatographed with synthetic LANT-6. The present immunocytochemical localization of LLI within cells in the inner nuclear and ganglion cell layers, coupled with the biochemical characterization of LANT-6 in the vertebrate retinas and brains, suggests that neuropeptides such as LANT-6 may play a role in visual processing both within the retina and within the visual pathways to the brain.
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264
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Li HB, Chen NX, Watt CB, Lam DM. The light microscopic localization of substance P- and somatostatin-like immunoreactive cells in the larval tiger salamander retina. Exp Brain Res 1986; 63:93-101. [PMID: 2426132 DOI: 10.1007/bf00235650] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Light microscopic immunocytochemistry was utilized to localize the populations of substance P (SP)- and somatostatin (SOM)-like immunoreactive cells in the larval tiger salamander retina. Of 104 SP-immunostained cells observed, 82% were Type 1 amacrine cells. Another 8% of the SP-cells were classified as Type 2 amacrine cells, while 10% of the SP-cells had their cell bodies located in the ganglion cell layer and were designated as displaced amacrine cells. Each type of SP-like immunoreactive cell was observed in the central and peripheral retina. SP-immunopositive processes were observed in the inner plexiform layer as a sparse plexus in sublamina 1 and as a denser network of fibers in sublamina 5. Seventy-eight percent of the 110 somatostatin-immunopositive cells observed were designated as Type 1 amacrine cells. Another 12% of SOM-cells were classified as displaced amacrine cells, while only two SOM-immunopositive Type 2 amacrine cells were observed. Nine percent of the SOM-cells were designated as interplexiform cells, based on their giving rise to processes distributing in the outer plexiform layer as well as processes ramifying in the inner plexiform layer. Each type of SOM-immunoreactive cell was observed in the central and peripheral retina, with the exception of the Type 2 amacrine cells, whose somas were only found in the central retina. Lastly, SOM-immunopositive processes in the inner plexiform layer appeared as a fine plexus in sublamina 1 and as a somewhat denser network of fibers in sublamina 5.
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265
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Li HB, Marshak DW, Dowling JE, Lam DM. Colocalization of immunoreactive substance P and neurotensin in amacrine cells of the goldfish retina. Brain Res 1986; 366:307-13. [PMID: 2421823 DOI: 10.1016/0006-8993(86)91308-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Using an immunohistochemical double-label technique, neurotensin and substance P immunoreactivity were localized to amacrine cells in the goldfish retina. Both peptides were found in a single population of unistratified amacrine cells branching in sublamina 3 of the inner plexiform layer. A monostratified amacrine cell branching in sublamina 1 contained only substance P immunoreactivity and a bistratified cell branching in sublaminae 1 and 3 contained only neurotensin immunoreactivity.
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266
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Watt CB, Li HB, Lam DM. The presence of three neuroactive peptides in putative glycinergic amacrine cells of an avian retina. Brain Res 1985; 348:187-91. [PMID: 2866019 DOI: 10.1016/0006-8993(85)90378-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Amacrine cells are retinal interneurons which serve to mediate transmission between bipolar and ganglion cells. To date, in addition to several classical neurotransmitters, a number of neuroactive peptides have been localized to these cells. We have previously demonstrated in the chicken that both peptide-transmitter and peptide-peptide colocalization exists in some amacrine cells. In this report, we show that 3 neuroactive peptides (enkephalin, neurotensin and somatostatin) are present in subpopulations of amacrine cells which also possess a high affinity uptake system for glycine. These observations suggest that the simultaneous visualization by autoradiography of [3H]glycine-uptake and immunocytochemistry of peptides may be useful for distinguishing between different types of putative glycinergic amacrine cells.
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267
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Watt CB, Li HB, Fry KR, Lam DM. Localization of enkephalin-like immunoreactive amacrine cells in the larval tiger salamander retina: a light and electron microscopic study. J Comp Neurol 1985; 241:171-9. [PMID: 3905883 DOI: 10.1002/cne.902410205] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Immunohistochemistry was utilized to examine the light and electron microscopic localization of enkephalin-like (enk) immunoreactive amacrine cells in the larval tiger salamander retina. The vast majority of enk-immunoreactive cells were typical amacrine cells whose round or oval cell bodies (14-16 microns) were situated in the innermost cell row of the inner nuclear layer. A relatively small number of enk-stained oval cell bodies (14-22 microns) were located in the ganglion cell layer and were designated as those of displaced amacrine cells. Enkephalin immunostaining was observed in the inner plexiform layer as a fine plexus in sublamina 1 and as a dense network of fibers in sublamina 5. In both the center and periphery of the retina the density of typical enk-amacrine cells was determined to be 250 +/- 16.36 cells per mm2 surface area of the retina. At the ultrastructural level typical enk-stained amacrine cells possessed a round, indented nuclear membrane. Enk-immunoreactive processes sometimes contained dense-core vesicles (60-115 nm) in addition to a rather homogeneous population of small, round, agranular synaptic vesicles (25-35 nm). In sublamina 1 the processes of enk-amacrine cells were presynaptic to amacrine and bipolar cells. They also contacted processes devoid of synaptic vesicles which possibly arise from ganglion cells. As the postsynaptic element in sublamina 1, they received synaptic input from amacrine cells. In sublamina 5 the processes of enk-amacrine cells were presynaptic to amacrine cells, bipolar cells, and the somas of cells situated in the ganglion cell layer.(ABSTRACT TRUNCATED AT 250 WORDS)
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268
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Li HB, Watt CB, Lam DM. The coexistence of two neuroactive peptides in a subpopulation of retinal amacrine cells. Brain Res 1985; 345:176-80. [PMID: 3904920 DOI: 10.1016/0006-8993(85)90850-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Amacrine cells are axonless interneurons of the vertebrate retina. Over the past few years many neuroactive peptides have been localized to these cells. We have previously demonstrated that a neuropeptide and a classical transmitter are colocalized in some amacrine cells. In this report, we show that two neuroactive peptides, which probably arise from different precursors, also coexist in some amacrine cells. Although some amacrine cells contain only enkephalin or neurotensin, others contain both of these neuroactive peptides.
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269
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Lam DM, Li HB, Su YY, Watt CB. The signature hypothesis: co-localizations of neuroactive substances as anatomical probes for circuitry analyses. Vision Res 1985; 25:1353-64. [PMID: 2868566 DOI: 10.1016/0042-6989(85)90213-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The recent discoveries that a neuron in the vertebrate retina may contain more than one neuroactive substance (transmitter or neuropeptide) raise the possibility that within each class of neurons, every morphologically and physiologically distinct cell type may be uniquely identified and categorized by the neuroactive substances that it contains. This article examines the evidence to-date for such a conjecture and discusses some of its potential applications and implications.
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