Primary sensory neuron : the international interdisciplinary journal reporting basic and clinical research on sensory receptors and primary afferent neurons最新文献
Pub Date : 1998-01-01DOI: 10.1163/092996398750132160
J. C. Holt, P. Guth, P. Perin, Charles A. Norris
Previous data from this group indicated that the main cholinergic effect on the afferent resting firing rate of the posterior canal is an atropine-sensitive, strychnine-resistant facilitation, while the main effect on the saccule is a strychnine-sensitive inhibition. In the present research we compared the effect of acetylcholine (ACh) on the afferent whole-nerve resting discharge of all vestibular organs of the frog. All three semicircular canals, utricle and lagena responded to ACh and carbachol (CCh) perfusion with an increase in resting discharge, while the saccular afferent discharge was mainly inhibited. The perfusion with 10 μ M physostigmine potentiated both facilitatory and inhibitory responses to ACh in all organs tested. On the other hand, CCh was much more potent than ACh in producing the facilitatory response but not the inhibitory response. As already observed in the posterior canal, the facilitation observed in the other vestibular organs was reversibly blocked by 1 or 10 μ M atropine but not by 1 μ M strychnine. In addition, the irreversible non-selective muscarinic antagonist propylbenzilylcholine mustard irreversibly abolished the facilitatory response but not the inhibitory one, while 50 μ M tetraethylammonium blocked the inhibitory response without affecting the facilitatory response or producing inhibition by itself. These results suggest that the predominant cholinergic response on the resting discharge is muscarinic in all vestibular organs of the frog except the saccule.
{"title":"A comparison of the cholinergic properties of the leopard frog vestibular organs","authors":"J. C. Holt, P. Guth, P. Perin, Charles A. Norris","doi":"10.1163/092996398750132160","DOIUrl":"https://doi.org/10.1163/092996398750132160","url":null,"abstract":"Previous data from this group indicated that the main cholinergic effect on the afferent resting firing rate of the posterior canal is an atropine-sensitive, strychnine-resistant facilitation, while the main effect on the saccule is a strychnine-sensitive inhibition. In the present research we compared the effect of acetylcholine (ACh) on the afferent whole-nerve resting discharge of all vestibular organs of the frog. All three semicircular canals, utricle and lagena responded to ACh and carbachol (CCh) perfusion with an increase in resting discharge, while the saccular afferent discharge was mainly inhibited. The perfusion with 10 μ M physostigmine potentiated both facilitatory and inhibitory responses to ACh in all organs tested. On the other hand, CCh was much more potent than ACh in producing the facilitatory response but not the inhibitory response. As already observed in the posterior canal, the facilitation observed in the other vestibular organs was reversibly blocked by 1 or 10 μ M atropine but not by 1 μ M strychnine. In addition, the irreversible non-selective muscarinic antagonist propylbenzilylcholine mustard irreversibly abolished the facilitatory response but not the inhibitory one, while 50 μ M tetraethylammonium blocked the inhibitory response without affecting the facilitatory response or producing inhibition by itself. These results suggest that the predominant cholinergic response on the resting discharge is muscarinic in all vestibular organs of the frog except the saccule.","PeriodicalId":82360,"journal":{"name":"Primary sensory neuron : the international interdisciplinary journal reporting basic and clinical research on sensory receptors and primary afferent neurons","volume":"2 1","pages":"275-282"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/092996398750132160","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64533632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1998-01-01DOI: 10.1163/092996398750132179
I. Thalmann, M. Henzl, R. Thalmann
The parvalbumins are small vertebrate-specific Ca 2+ -binding proteins. The mammalian α -parvalbumin is expressed in diverse cell types, including the inner hair cell, where it is proposed to serve as a cytosolic Ca 2+ buffer. By contrast, the mammalian β -parvalbumin (oncomodulin) has a highly restricted distribution and harbors a 'Ca 2+ -specific' site — properties consistent with Ca 2+ -dependent regulatory behavior. The widespread perception of oncomodulin as an oncofetal protein was recently shattered by our discovery that the protein is present in the organ of Corti. Immunohistochemical data for the rat, mouse and gerbil indicate that expression is in fact confined to the outer hair cell. We have sought to confirm and extend this work through biochemical quantitation studies on organ of Corti from rat, mouse, guinea pig and chinchilla. We find that the protein is expressed at comparably high levels (approximately 0.5 mM) in the outer hair cells in all four species. This finding contrasts sharply with the expression pattern in prenatal and neoplastic settings. We have also extended the immunohistochemical analysis to the guinea pig and performed preliminary analysis of oncomodulin mRNA levels by in situ hydridization. On the basis of our data, we suggest that the outer hair cell is the sole site of physiologically relevant oncomodulin expression. Furthermore, we propose that the protein functions in the efferent control of the electromotile response.
{"title":"Novel calcium sensor in the outer hair cells: quantitation of oncomodulin","authors":"I. Thalmann, M. Henzl, R. Thalmann","doi":"10.1163/092996398750132179","DOIUrl":"https://doi.org/10.1163/092996398750132179","url":null,"abstract":"The parvalbumins are small vertebrate-specific Ca 2+ -binding proteins. The mammalian α -parvalbumin is expressed in diverse cell types, including the inner hair cell, where it is proposed to serve as a cytosolic Ca 2+ buffer. By contrast, the mammalian β -parvalbumin (oncomodulin) has a highly restricted distribution and harbors a 'Ca 2+ -specific' site — properties consistent with Ca 2+ -dependent regulatory behavior. The widespread perception of oncomodulin as an oncofetal protein was recently shattered by our discovery that the protein is present in the organ of Corti. Immunohistochemical data for the rat, mouse and gerbil indicate that expression is in fact confined to the outer hair cell. We have sought to confirm and extend this work through biochemical quantitation studies on organ of Corti from rat, mouse, guinea pig and chinchilla. We find that the protein is expressed at comparably high levels (approximately 0.5 mM) in the outer hair cells in all four species. This finding contrasts sharply with the expression pattern in prenatal and neoplastic settings. We have also extended the immunohistochemical analysis to the guinea pig and performed preliminary analysis of oncomodulin mRNA levels by in situ hydridization. On the basis of our data, we suggest that the outer hair cell is the sole site of physiologically relevant oncomodulin expression. Furthermore, we propose that the protein functions in the efferent control of the electromotile response.","PeriodicalId":82360,"journal":{"name":"Primary sensory neuron : the international interdisciplinary journal reporting basic and clinical research on sensory receptors and primary afferent neurons","volume":"2 1","pages":"283-296"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/092996398750132179","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64533644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Subcutaneous lidocaine (0.1%) and N-propylajmaline (NPA, 0.01%), inhibited pressure- and heat-evoked discharges in feline cutaneous C-fiber mechano-heat-sensitive (CMH) units. Initial suppression of discharges was followed by the period of resting and use-dependent (UD) inhibition, evaluated with double thermal (50 °C, 10 s) or triple mechanical (0.5 N/mm2, 3 s) stimuli, repeatedly applied after prolong pauses. Resting inhibition of pressure responses decreased the maximum discharge rate (MDR) evoked by the first stimulus in a train from the control value of 10.3 ± 1.5 Hz (n = 15, SEM) to 4.1± 1.0 Hz (n = 7) for lidocaine and to 6.3± 1.0 Hz (n = 15) for NPA. UD inhibition further decreased MDR evoked by the second and the third stimulus in a train: for lidocaine to 1.0 ± 0.7 Hz (n = 7) and 0.2 ± 0.1 Hz (n = 7); for NPA to 2.1 ± 0.8 Hz (n = 15) and 0.2 ± 0.1 Hz (n = 15). Resting inhibition of heat discharges decreased MDR evoked by the first stimulus from the control value of 6.0 ± 1.0 Hz (n = 28) to 2.4 ± 0.5 Hz (n = 8) for lidocaine and to 2.8 ± 0.3 Hz (n = 20) for NPA. UD inhibition further decreased MDR evoked by the second stimulus: in percentage to the first one, MDR was 57±14% (n = 8) for lidocaine and 56 ± 7% (n = 20) for NPA. Lidocaine and NPA transformed discharges evoked by a ramp heat stimulus, maintaining low frequencies (MDR < 2-3 Hz) and eliminating the higher ones. Tertiary amine lidocaine, but not quaternary NPA, elevated the thermal threshold by 2.8± 0.9 °C (n = 24, P < 0.01). UD inhibition of CMH unit termination indicates that it contains ionic channels with slow kinetics, thought to be tetrodotoxin-resistant sodium channels. Such UD inhibition allows us to explain the analgesic action of local anesthetics in low (subblocking) concentrations and propose local analgesia, which cuts the nociceptive signals off, but maintains the non-nociceptive ones.
{"title":"Transformation of pressure- and heat-induced discharges of feline cutaneous C-fiber mechano-heat-sensitive units by lidocaine and N-propylajmaline","authors":"Revenko, Ermishkin, Borovikov, Borovikova","doi":"10.1163/092996398744712","DOIUrl":"https://doi.org/10.1163/092996398744712","url":null,"abstract":"Subcutaneous lidocaine (0.1%) and N-propylajmaline (NPA, 0.01%), inhibited pressure- and heat-evoked discharges in feline cutaneous C-fiber mechano-heat-sensitive (CMH) units. Initial suppression of discharges was followed by the period of resting and use-dependent (UD) inhibition, evaluated with double thermal (50 °C, 10 s) or triple mechanical (0.5 N/mm2, 3 s) stimuli, repeatedly applied after prolong pauses. Resting inhibition of pressure responses decreased the maximum discharge rate (MDR) evoked by the first stimulus in a train from the control value of 10.3 ± 1.5 Hz (n = 15, SEM) to 4.1± 1.0 Hz (n = 7) for lidocaine and to 6.3± 1.0 Hz (n = 15) for NPA. UD inhibition further decreased MDR evoked by the second and the third stimulus in a train: for lidocaine to 1.0 ± 0.7 Hz (n = 7) and 0.2 ± 0.1 Hz (n = 7); for NPA to 2.1 ± 0.8 Hz (n = 15) and 0.2 ± 0.1 Hz (n = 15). Resting inhibition of heat discharges decreased MDR evoked by the first stimulus from the control value of 6.0 ± 1.0 Hz (n = 28) to 2.4 ± 0.5 Hz (n = 8) for lidocaine and to 2.8 ± 0.3 Hz (n = 20) for NPA. UD inhibition further decreased MDR evoked by the second stimulus: in percentage to the first one, MDR was 57±14% (n = 8) for lidocaine and 56 ± 7% (n = 20) for NPA. Lidocaine and NPA transformed discharges evoked by a ramp heat stimulus, maintaining low frequencies (MDR < 2-3 Hz) and eliminating the higher ones. Tertiary amine lidocaine, but not quaternary NPA, elevated the thermal threshold by 2.8± 0.9 °C (n = 24, P < 0.01). UD inhibition of CMH unit termination indicates that it contains ionic channels with slow kinetics, thought to be tetrodotoxin-resistant sodium channels. Such UD inhibition allows us to explain the analgesic action of local anesthetics in low (subblocking) concentrations and propose local analgesia, which cuts the nociceptive signals off, but maintains the non-nociceptive ones.","PeriodicalId":82360,"journal":{"name":"Primary sensory neuron : the international interdisciplinary journal reporting basic and clinical research on sensory receptors and primary afferent neurons","volume":"4 1","pages":"31-48"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/092996398744712","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64533458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Intraneural microstimulation of single tactile or kinaesthetic afferent fibres arising in the hand of conscious human subjects has revealed marked differences among the different classes in their capacity to generate a perceptual response. In order to test the hypothesis that these different capacities might reflect a differential security in the transmission of singnals across synaptic junctions in the dorsal column nuclei or other levels of the somatosensory pathway we have previously developed a paired, simultaneous recording paradigm in the cat to analyze transmission characteristics within the dorsal column nuclei for single identified tactile and muscle sensory fibres of the forearm. These studies have depended upon the use of a fine peripheral nerve or nerve fascicle preparation in which it is possible to monitor the activity of single sensory fibres while the nerve remains in continuity with the central nervous system. Although we have previously described a preparation that allows the activity of single joint afferent fibres from the hindlimb to be monitored in the intact medial articular nerve, these hindlimb kinaesthetic afferents fail to project directly to the dorsal column nuclei. In the present study we report a forearm nerve preparation in the cat that permits the simultaneous recording of activity from individual wrist joint afferent fibres and their target neurones of the dorsal column nuclei. When this nerve is freed from nearby tissue over a distance of 2-4 cm and left in continuity, it is possible with a silver hook electrode to monitor the impulse activity of each group II joint afferent fibre with an excellent signal-to-noise ratio. The preparation should prove ideal for examining the central actions and security of transmission across the dorsal column nuclei for single, identified joint afferent fibres of the forearm.
{"title":"An intact peripheral nerve preparation for examining the central actions of single kinaesthetic afferent fibres arising in the wrist joint of the cat","authors":"P. D. Mackie, Rowe, Coleman, Zhang","doi":"10.1163/092996398744730","DOIUrl":"https://doi.org/10.1163/092996398744730","url":null,"abstract":"Intraneural microstimulation of single tactile or kinaesthetic afferent fibres arising in the hand of conscious human subjects has revealed marked differences among the different classes in their capacity to generate a perceptual response. In order to test the hypothesis that these different capacities might reflect a differential security in the transmission of singnals across synaptic junctions in the dorsal column nuclei or other levels of the somatosensory pathway we have previously developed a paired, simultaneous recording paradigm in the cat to analyze transmission characteristics within the dorsal column nuclei for single identified tactile and muscle sensory fibres of the forearm. These studies have depended upon the use of a fine peripheral nerve or nerve fascicle preparation in which it is possible to monitor the activity of single sensory fibres while the nerve remains in continuity with the central nervous system. Although we have previously described a preparation that allows the activity of single joint afferent fibres from the hindlimb to be monitored in the intact medial articular nerve, these hindlimb kinaesthetic afferents fail to project directly to the dorsal column nuclei. In the present study we report a forearm nerve preparation in the cat that permits the simultaneous recording of activity from individual wrist joint afferent fibres and their target neurones of the dorsal column nuclei. When this nerve is freed from nearby tissue over a distance of 2-4 cm and left in continuity, it is possible with a silver hook electrode to monitor the impulse activity of each group II joint afferent fibre with an excellent signal-to-noise ratio. The preparation should prove ideal for examining the central actions and security of transmission across the dorsal column nuclei for single, identified joint afferent fibres of the forearm.","PeriodicalId":82360,"journal":{"name":"Primary sensory neuron : the international interdisciplinary journal reporting basic and clinical research on sensory receptors and primary afferent neurons","volume":"3 1","pages":"61-70"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/092996398744730","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64533510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1998-01-01DOI: 10.1163/092996398750132133
A. Rüsch, J. R. Holt, R. Eatock, Melissa A. Vollrath
The mechanoelectrical transduction currents of hair cells in the mouse utricle adapt at varying rates to step deflections of the hair bundles. We consider contributions of this adaptation process and of input resistance and membrane capacitance to the frequency dependence of the receptor potential. Whole-cell recordings of transduction current and receptor potential were made from hair cells in the excised epithelium of the mouse utricle. Hair bundles were deflected by a fluid jet with step and sinusoidal waveforms. In type II cells, the receptor potential was a bandpass function of stimulus frequency. The adaptation rate of the transduction current, measured in response to step bundle deflections, accounted for much of the roll-off in the receptor potential at low frequencies of sinusoidal deflections. Corner frequencies predicted from the adaptation time course varied from 2 to 60 Hz. Voltage-gated conductances also contributed. Roll-off of the receptor potential at the high-frequency end may largely reflect input resistance and capacitance. Corner frequencies predicted by estimated membrane time constants varied from 30 to 150 Hz. In type I cells, slower or no adaptation and shorter membrane time constants predict larger response bandwidths. Frequency tuning in vivo will reflect other factors, including the mechanical response of the otolith and otolithic membrane to head movements.
{"title":"The frequency dependence of receptor potentials in hair cells of the mouse utricle","authors":"A. Rüsch, J. R. Holt, R. Eatock, Melissa A. Vollrath","doi":"10.1163/092996398750132133","DOIUrl":"https://doi.org/10.1163/092996398750132133","url":null,"abstract":"The mechanoelectrical transduction currents of hair cells in the mouse utricle adapt at varying rates to step deflections of the hair bundles. We consider contributions of this adaptation process and of input resistance and membrane capacitance to the frequency dependence of the receptor potential. Whole-cell recordings of transduction current and receptor potential were made from hair cells in the excised epithelium of the mouse utricle. Hair bundles were deflected by a fluid jet with step and sinusoidal waveforms. In type II cells, the receptor potential was a bandpass function of stimulus frequency. The adaptation rate of the transduction current, measured in response to step bundle deflections, accounted for much of the roll-off in the receptor potential at low frequencies of sinusoidal deflections. Corner frequencies predicted from the adaptation time course varied from 2 to 60 Hz. Voltage-gated conductances also contributed. Roll-off of the receptor potential at the high-frequency end may largely reflect input resistance and capacitance. Corner frequencies predicted by estimated membrane time constants varied from 30 to 150 Hz. In type I cells, slower or no adaptation and shorter membrane time constants predict larger response bandwidths. Frequency tuning in vivo will reflect other factors, including the mechanical response of the otolith and otolithic membrane to head movements.","PeriodicalId":82360,"journal":{"name":"Primary sensory neuron : the international interdisciplinary journal reporting basic and clinical research on sensory receptors and primary afferent neurons","volume":"3 1","pages":"233-241"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/092996398750132133","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64533574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Among chemoreceptor cells of the blowfly ( Protophormia terraenovae , the so-called 'sugar' and 'water' cells respond to bovine serum albumin (BSA) and L -alanine (the C-terminal amino acid of the BSA molecule) with the highest spike frequency. In both cell types the response to either BSA or L -alanine was unaffected by 0.1 mM amiloride. However, 0.5 mM amiloride decreased the response of the 'water' cell to both BSA and L-alanine significantly, and similarly inhibited the response of the 'sugar' cell to L -alanine, but in contrast to the 'water' cell, 0.5 mM amiloride did not affect the 'sugar' cell response to BSA. The 'sugar' cell responses to both BSA and L-alanine were unaffected by the putative cell second messengers, cAMP and cGMP. The so-called 'anion' cell unexpectedly gave responses to BSA and L-alanine that were enhanced by amiloride at both concentrations. However, like the 'sugar' cell, the 'anion' cell was also unaffected by cAMP and cGMP.We conclude that the 'sugar' cell must have at least three types of receptor sites: the previously described 'F' (amiloride sensitive) and the 'P' (amiloride insensitive) sites, and a low-sensitivity 'T' site that mediates, at least in part, the response to BSA and L -alanine. The effects of amiloride on the responses of the 'water' and 'anion' cells are more difficult to interpret because fundamental information on their chemoreception mechanisms is still lacking.
在苍蝇的化学感受器细胞中，所谓的“糖”和“水”细胞对牛血清白蛋白(BSA)和L -丙氨酸(BSA分子的c端氨基酸)的反应频率最高。在这两种细胞类型中，对BSA或L -丙氨酸的反应均不受0.1 mM阿米洛利的影响。然而，0.5 mM amiloride显著降低了“水”细胞对BSA和L-丙氨酸的反应，同样抑制了“糖”细胞对L-丙氨酸的反应，但与“水”细胞相比，0.5 mM amiloride不影响“糖”细胞对BSA的反应。糖细胞对BSA和l -丙氨酸的反应不受假定的细胞第二信使cAMP和cGMP的影响。所谓的“阴离子”细胞意外地对两种浓度的阿米洛利都增强的BSA和l -丙氨酸产生反应。然而，像糖细胞一样，阴离子细胞也不受cAMP和cGMP的影响。我们得出结论，“糖”细胞必须至少有三种类型的受体位点:先前描述的“F”(阿米洛利敏感)和“P”(阿米洛利不敏感)位点，以及至少部分介导对BSA和L -丙氨酸反应的低敏感性“T”位点。阿米洛利对“水”和“阴离子”细胞反应的影响更难解释，因为它们的化学接受机制的基本信息仍然缺乏。
{"title":"Amiloride high- and low-sensitivity, as well as insensitive sites in the blowfly: implications for sugar, water and anion taste reception mechanisms","authors":"Majone, A. L. P.Solari, Crnjar","doi":"10.1163/092996398744721","DOIUrl":"https://doi.org/10.1163/092996398744721","url":null,"abstract":"Among chemoreceptor cells of the blowfly ( Protophormia terraenovae , the so-called 'sugar' and 'water' cells respond to bovine serum albumin (BSA) and L -alanine (the C-terminal amino acid of the BSA molecule) with the highest spike frequency. In both cell types the response to either BSA or L -alanine was unaffected by 0.1 mM amiloride. However, 0.5 mM amiloride decreased the response of the 'water' cell to both BSA and L-alanine significantly, and similarly inhibited the response of the 'sugar' cell to L -alanine, but in contrast to the 'water' cell, 0.5 mM amiloride did not affect the 'sugar' cell response to BSA. The 'sugar' cell responses to both BSA and L-alanine were unaffected by the putative cell second messengers, cAMP and cGMP. The so-called 'anion' cell unexpectedly gave responses to BSA and L-alanine that were enhanced by amiloride at both concentrations. However, like the 'sugar' cell, the 'anion' cell was also unaffected by cAMP and cGMP.We conclude that the 'sugar' cell must have at least three types of receptor sites: the previously described 'F' (amiloride sensitive) and the 'P' (amiloride insensitive) sites, and a low-sensitivity 'T' site that mediates, at least in part, the response to BSA and L -alanine. The effects of amiloride on the responses of the 'water' and 'anion' cells are more difficult to interpret because fundamental information on their chemoreception mechanisms is still lacking.","PeriodicalId":82360,"journal":{"name":"Primary sensory neuron : the international interdisciplinary journal reporting basic and clinical research on sensory receptors and primary afferent neurons","volume":"3 1","pages":"49-59"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/092996398744721","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64533473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1998-01-01DOI: 10.1163/092996398750132151
Hirota Hara, Xiangdong Chen, Jershonda F. Hartsfield, J. Hara, D. Martin, C. Fermin
Neurons from the vestibular (VG) and the statoacoustic (SAG) ganglion of the chick (Gallus domesticus) were evaluated histologically and morphometrically. Embryos at stages 34 (E8 days), 39 (E13 days) and 44 (E18 days) were sacrificed and temporal bones microdissected. Specimens were embedded in JB-4 methacrylate plastic, and stained with a mixture of 0.2% toluidine blue (TB) and 0.1% basic Fuschin in 25% ethanol or with a mixture of 2% TB and 1% paraphenylenediamine (PDA) for axon and myelin measurement study. Images of the VIIIth nerve were produced by a V150 (R) color imaging system and the contour of 200-300 neuronal bodies (perikarya) was traced directly on a video screen with a mouse in real time. The cross-sectional area of VG perikarya was 67.29 micrometers2 at stage 34 (E8), 128.46 micrometers2 at stage 39 (E13) and 275.85 micrometers2 at stage 44 (E18). The cross-sectional area of SAG perikarya was 62.44 micrometers2 at stage 34 (E8), 102.05 micrometers2 at stage 39 (E13) and 165.02 micrometers2 at stage 44 (E18). A significant cross-sectional area increase of the VG perikarya between stage 39 (E13) and stage 44 (E18) was determined. We randomly measured the cross-sectional area of myelin and axoplasm of hatchling afferent nerves, and found a correspondence between axoplasmic and myelin cross-sectional area in the utricular, saccular and semicircular canal nerve branches of the nerve. The results suggest that the period between stage 34 (E8) and 39 (E13) is a critical period for afferent neuronal development. Physiological and behavioral vestibular properties of developing and maturing hatchlings may change accordingly. The results compliment previous work by other investigators and provide valuable anatomical measures useful to correlate physiological data obtained from stimulation of the whole nerve or its parts.
{"title":"Chicken (Gallus domesticus) inner ear afferents.","authors":"Hirota Hara, Xiangdong Chen, Jershonda F. Hartsfield, J. Hara, D. Martin, C. Fermin","doi":"10.1163/092996398750132151","DOIUrl":"https://doi.org/10.1163/092996398750132151","url":null,"abstract":"Neurons from the vestibular (VG) and the statoacoustic (SAG) ganglion of the chick (Gallus domesticus) were evaluated histologically and morphometrically. Embryos at stages 34 (E8 days), 39 (E13 days) and 44 (E18 days) were sacrificed and temporal bones microdissected. Specimens were embedded in JB-4 methacrylate plastic, and stained with a mixture of 0.2% toluidine blue (TB) and 0.1% basic Fuschin in 25% ethanol or with a mixture of 2% TB and 1% paraphenylenediamine (PDA) for axon and myelin measurement study. Images of the VIIIth nerve were produced by a V150 (R) color imaging system and the contour of 200-300 neuronal bodies (perikarya) was traced directly on a video screen with a mouse in real time. The cross-sectional area of VG perikarya was 67.29 micrometers2 at stage 34 (E8), 128.46 micrometers2 at stage 39 (E13) and 275.85 micrometers2 at stage 44 (E18). The cross-sectional area of SAG perikarya was 62.44 micrometers2 at stage 34 (E8), 102.05 micrometers2 at stage 39 (E13) and 165.02 micrometers2 at stage 44 (E18). A significant cross-sectional area increase of the VG perikarya between stage 39 (E13) and stage 44 (E18) was determined. We randomly measured the cross-sectional area of myelin and axoplasm of hatchling afferent nerves, and found a correspondence between axoplasmic and myelin cross-sectional area in the utricular, saccular and semicircular canal nerve branches of the nerve. The results suggest that the period between stage 34 (E8) and 39 (E13) is a critical period for afferent neuronal development. Physiological and behavioral vestibular properties of developing and maturing hatchlings may change accordingly. The results compliment previous work by other investigators and provide valuable anatomical measures useful to correlate physiological data obtained from stimulation of the whole nerve or its parts.","PeriodicalId":82360,"journal":{"name":"Primary sensory neuron : the international interdisciplinary journal reporting basic and clinical research on sensory receptors and primary afferent neurons","volume":"97 1","pages":"253-74"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85938338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The action of tetraethylammonium (TEA) (20 mM) and 4-aminopyridine (4-AP) (5 mM) on mechano- and electrically excitable membranes of the Pacinian corpuscles was studied by means of the air gap technique in constantly perfused preparations. Extracellular recordings of receptor potential have shown that application of TEA causes 1.5-fold prolongation of the receptor potential and a decrease of its amplitude by 40%. 4-AP has no effect on the mechanosensitive membrane. The difference in the blockers effect testifies that repolarization of the receptor potential is not regulated by the voltage-dependent potassium channels. The blockers considered are likely effect on the calcium-dependent potassium currents activated by Ca 2+ ions passing through the non-selective channels opening in response to mechanical stimulus. TEA and 4-AP induce a 2- to 3-fold increase of the action potential duration in the electrically excitable membrane of the Ranvier node. Computations based on the Dodge model help reveal that inhibition of the voltage-dependent potassium channels accounts for this increase.
{"title":"The effect of tetraethylammonium and 4-aminopyridine on mechano- and electrosensitive channels of the Pacinian corpuscle","authors":"Krylov, Dick, Akoev","doi":"10.1163/092996398744695","DOIUrl":"https://doi.org/10.1163/092996398744695","url":null,"abstract":"The action of tetraethylammonium (TEA) (20 mM) and 4-aminopyridine (4-AP) (5 mM) on mechano- and electrically excitable membranes of the Pacinian corpuscles was studied by means of the air gap technique in constantly perfused preparations. Extracellular recordings of receptor potential have shown that application of TEA causes 1.5-fold prolongation of the receptor potential and a decrease of its amplitude by 40%. 4-AP has no effect on the mechanosensitive membrane. The difference in the blockers effect testifies that repolarization of the receptor potential is not regulated by the voltage-dependent potassium channels. The blockers considered are likely effect on the calcium-dependent potassium currents activated by Ca 2+ ions passing through the non-selective channels opening in response to mechanical stimulus. TEA and 4-AP induce a 2- to 3-fold increase of the action potential duration in the electrically excitable membrane of the Ranvier node. Computations based on the Dodge model help reveal that inhibition of the voltage-dependent potassium channels accounts for this increase.","PeriodicalId":82360,"journal":{"name":"Primary sensory neuron : the international interdisciplinary journal reporting basic and clinical research on sensory receptors and primary afferent neurons","volume":"3 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/092996398744695","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64533377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1998-01-01DOI: 10.1163/092996398750132142
G. Meza, Jang-Yen Wu, H. Zepeda, C. José
In order to investigate a putative neurotransmitter function of γ-aminobutyric acid (GABA) in the rat vestibule we chose to study the cellular localization and properties of glutamic acid decarboxylase (GAD), the rate-limiting enzyme for the synthesis of GABA, in the rat ampullary cristae, with respective immunocytochemical and immunoblotting techniques, using an extensively characterized rabbit anti-GAD serum. With these procedures we found a GAD-like immunopositivity in the sensory cells and in fibers of the crista ampullaris stroma. In ampullary cristae homogenates, a GAD composed of at least two subunits (53 and 67 kDa which were present also in rat brain and cerebellum homogenates) was encountered. These findings suggest that GAD present in the rat vestibule is homologous to the brain enzyme and it has the appropriate localization to synthesize GABA to be used as a neurotransmitter in the rat vestibule.
{"title":"Glutamic acid decarboxylase in the rat ampullary cristae: immunocytochemical and immunoblotting studies","authors":"G. Meza, Jang-Yen Wu, H. Zepeda, C. José","doi":"10.1163/092996398750132142","DOIUrl":"https://doi.org/10.1163/092996398750132142","url":null,"abstract":"In order to investigate a putative neurotransmitter function of γ-aminobutyric acid (GABA) in the rat vestibule we chose to study the cellular localization and properties of glutamic acid decarboxylase (GAD), the rate-limiting enzyme for the synthesis of GABA, in the rat ampullary cristae, with respective immunocytochemical and immunoblotting techniques, using an extensively characterized rabbit anti-GAD serum. With these procedures we found a GAD-like immunopositivity in the sensory cells and in fibers of the crista ampullaris stroma. In ampullary cristae homogenates, a GAD composed of at least two subunits (53 and 67 kDa which were present also in rat brain and cerebellum homogenates) was encountered. These findings suggest that GAD present in the rat vestibule is homologous to the brain enzyme and it has the appropriate localization to synthesize GABA to be used as a neurotransmitter in the rat vestibule.","PeriodicalId":82360,"journal":{"name":"Primary sensory neuron : the international interdisciplinary journal reporting basic and clinical research on sensory receptors and primary afferent neurons","volume":"2 1","pages":"243-251"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/092996398750132142","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64533589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1998-01-01DOI: 10.1163/092996398750132188
T. Park, P. Weisleder, Ying Lu
Previous investigations into the anatomy of the inner ear of Belgian Waterslager canaries (BWC) have demonstrated myriad malformations associated with dysgenesis of the pars inferior of the otocyst. These malformations are associated with a congenital hearing impairment primarily affecting mid to high frequencies. Specific hair cell abnormalities include irregular cell boundaries, deformed cuticular plate, and multiple and deformed stereocilia tufts. This constellation of structural deformities lead us to hypothesize that the content of non-muscle filamentous protein in BWC hair cells need be abnormal. As a first step in exploring this hypothesis, we have used immunocytochemical techniques to assess the presence and distribution of the major components of the actin microfilament system, i.e. actin, tropomyosin and α -actinin, at the apical end of hair cells from the BWC basilar papilla. Our results show qualitative differences between control and BWC hair cells. First, label of the BWC cuticular plate was scattered and ill-matched with that of control birds for each of the three proteins examined. Second, labeling of BWC cilia revealed abnormal distribution of the assessed proteins. Specifically, anti-actin and anti- α -actinin antibodies were clustered over the cilia, while immunostaining against tropomyosin was not seen. These findings support a link between the proteins associated with cochlear hair cell structural integrity and the dysmorphologies associated with the congenital hearing impairment identified in the BWC model.
{"title":"Hair cells of a congenitally hearing impaired canary have abnormal distribution of filamentous proteins","authors":"T. Park, P. Weisleder, Ying Lu","doi":"10.1163/092996398750132188","DOIUrl":"https://doi.org/10.1163/092996398750132188","url":null,"abstract":"Previous investigations into the anatomy of the inner ear of Belgian Waterslager canaries (BWC) have demonstrated myriad malformations associated with dysgenesis of the pars inferior of the otocyst. These malformations are associated with a congenital hearing impairment primarily affecting mid to high frequencies. Specific hair cell abnormalities include irregular cell boundaries, deformed cuticular plate, and multiple and deformed stereocilia tufts. This constellation of structural deformities lead us to hypothesize that the content of non-muscle filamentous protein in BWC hair cells need be abnormal. As a first step in exploring this hypothesis, we have used immunocytochemical techniques to assess the presence and distribution of the major components of the actin microfilament system, i.e. actin, tropomyosin and α -actinin, at the apical end of hair cells from the BWC basilar papilla. Our results show qualitative differences between control and BWC hair cells. First, label of the BWC cuticular plate was scattered and ill-matched with that of control birds for each of the three proteins examined. Second, labeling of BWC cilia revealed abnormal distribution of the assessed proteins. Specifically, anti-actin and anti- α -actinin antibodies were clustered over the cilia, while immunostaining against tropomyosin was not seen. These findings support a link between the proteins associated with cochlear hair cell structural integrity and the dysmorphologies associated with the congenital hearing impairment identified in the BWC model.","PeriodicalId":82360,"journal":{"name":"Primary sensory neuron : the international interdisciplinary journal reporting basic and clinical research on sensory receptors and primary afferent neurons","volume":"2 1","pages":"297-303"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/092996398750132188","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64533206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Primary sensory neuron : the international interdisciplinary journal reporting basic and clinical research on sensory receptors and primary afferent neurons
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