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Morphological identification of physiologically characterized afferents innervating the turtle posterior crista

JOURNAL OF NEUROPHYSIOLOGY 2000年第3期83卷 1202-1223页

作者： Brichta, AM Goldberg, JM Univ Chicago Dept Neurobiol Pharmacol & Physiol Chicago IL 60637 USA Univ Chicago Dept Surg Otolaryngol Head & Neck Surg Chicago IL 60637 USA

The turtle posterior crista consists of two hemicristae. Each hemicrista extends from the planum semilunatum to the nonsensory torus and includes a central zone (CZ) surrounded by a peripheral zone (PZ). Type I and type II: hair cells are found in the CZ and are innervated by calyx, dimorphic and bouton afferents. Only type II hair cells and bouton fibers are found In the PZ. Units were intraaxonally labeled in a half-head preparation. Bouton (B) units could be near the planum (BP), near the torus (BT), or in midportions of a hemicrista, including the PZ and CZ. Discharge properties of B units vary with longitudinal position in a hemicrista but not with morphological features of their peripheral terminations. BP units are regularly discharging and have small gains and small phase leads re angular head velocity. BT units are irregular and have large gains and large phase leads. BM units have intermediate properties. Calyx (C) and dimorphic (D) units have similar discharge properties and were placed into a single calyx-bearing (CD) category. While having an irregular discharge resembling BT units, CD units have gains and phases similar to those of BM units. Rather than any single discharge property, it is the relation between discharge regularity and either gain or phase that makes CD units distinctive. Multivariate statistical formulas were developed to infer a unit's morphological class (B or CD) and longitudinal position solely from its discharge properties. To verify the use of the formulas, discharge properties were compared for units recorded intraaxonally or extracellularly in the half-head or extracellularly in intact animals. Most B units have background rates of 10-30 spikes/s. The CD category was separated into CD-high and CD-low units with background rates above or below 5 spikes/s, respectively. CD-low units have lower gains and phases and are located nearer the planum than CD-high units. In their response dynamics over a frequency range from 0.01-3 Hz, B

关键词：算法轴突/生理学贝叶斯定理脑/解剖学和组织学脑/细胞学脑/生理学脑图耳蜗神经/生理学电生理学功能偏侧化/生理学毛细胞听觉/生理学神经纤维/生理学神经元传入/生理学旋转龟/解剖学和组织学龟/生理学动物女(雌)性男(雄)性

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Rate-intensity functions in the emu auditory nerve

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JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2000年第4期107卷 2143-2154页

作者： Yates, GK Manley, GA Köppl, C Univ Western Australia Dept Physiol Auditory Lab Nedlands WA 6009 Australia Tech Univ Munich Inst Zool D-85747 Garching Germany

Rate-versus-intensity functions recorded from mammalian auditory-nerve fibers have been shown to form a continuum of shapes, ranging from saturating to straight and correlating well with spontaneous rate and sensitivity. These variations are believed to be a consequence of the interaction between the sensitivity of the hair-cell afferent synapse and the nonlinear, compressive growth of the cochlear amplifier that enhances mechanical vibrations on the basilar membrane. Little is known, however, about the cochlear amplifier in other vertebrate species. Rate-intensity functions were recorded from auditory-nerve fibers in chicks of the emu, a member of the Ratites, a primitive group of flightless birds that have poorly differentiated short and tall hair cells. Recorded data were found to be well fitted by analytical functions which have previously been shown to represent well the shapes of rate-intensity functions in guinea pigs. At the fibers' most sensitive frequencies, rate-intensity functions were almost exclusively of the sloping (80.9%) or straight (18.6%) type. Flat-saturating functions, the most common type in the mammal, represented only about 0.5% of the total in the emu. Below the best frequency of each fiber, the rate-intensity functions tended more towards the Aat-saturating type, as is the case in mammals;a similar but weaker trend was seen above best frequency in most fibers, with only a small proportion (18%) showing the reverse trend. The emu rate-intensity functions were accepted as supporting previous evidence for the existence of a cochlear amplifier in birds, the conclusion was drawn further that the nonlinearity observed is probably due to saturation of the hair-cell transduction mechanism. (C) 2000 Acoustical Society of America. [S0001-4966(00)05903-8].

关键词：动物新生/生理学听阈/生理学耳蜗神经/生理学鸸鹋科/生理学电生理学模型神经学神经纤维/生理学动物

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FIELD POTENTIALS AND EXCITATION OF PRIMATE SPINOTHALAMIC NEURONS IN RESPONSES TO VOLLEYS IN MUSCLE AFFERENTS

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JOURNAL OF PHYSIOLOGY-LONDON 1979年第JAN期286卷 197-213页

作者： FOREMAN, RD KENSHALO, DR SCHMIDT, RF WILLIS, WD UNIV TEXAS MED BRANCH DEPT ANAT GALVESTON TX 77550 USA UNIV TEXAS MED BRANCH INST MARINE BIOMED GALVESTON TX 77550 USA UNIV TEXAS MED BRANCH DEPT PHYSIOL & BIOPHYS GALVESTON TX 77550 USA UNIV KIEL INST PHYSIOL LEHRSTUHL 1 D-2300 KIEL 1 FED REP GER

An anesthetized monkeys [Macaca fascicularis], stimulation of muscle afferents results in a sequence of cord dorsum potentials. These include a group I volley followed by several negative potentials called here the NI, NII and NIII waves. Evidence based on the effects of graded stimulus strengths, measurements of latencies, and the results of anodal blockade of large muscle afferents indicate that the NI, NII and NIII waves are evoked, respectively, by group I, II and III muscle afferents. The NII and NIII waves appear to be confined to the lumbosacral enlargement when evoked by hind limb muscle afferents. The group I volley and NI wave can be detected at least as far rostrally as L [lumbar] 3. The NII and NIII waves were mapped in the depth of the cord. The maxima for these waves were found in the neck of the dorsal horn. The waves reversed to become positive in the ventral horn. Using graded electrical stimulation of muscle nerves a few spinothalamic tract neurons could be activated monosynaptically by group I volleys;other spinothalamic cells may have been activated polysynaptically by group I volleys. The lack of any substantial excitation of spinothalamic neurons by intra-arterial injections of succinylcholine suggests that these group I actions may be due to group Ib afferents from Golgi tendon organs. The most potent excitation of spinothalamic tract cells was due to the action of middle sized and small muscle afferents. Evidence was obtained for an excitatory action of group II, III and IV afferents. There was a good correlation between the effects of graded stimulation in evoking discharges in separate bursts associated with the arrival of volleys in group II and group III afferents and the generation of the NII and NIII waves. Some spinothalamic neurons, including several located in lamina I, were unaffected by the muscle afferent volleys used. Such neurons might help to signal well localized pain, whereas the cells which respond to a variety of cutaneous

关键词：诱发电位直鼻猴亚目后肢/神经支配成束猴肌/神经支配神经纤维/生理学神经元/生理学神经元传入/生理学脊髓丘脑束/细胞学脊髓丘脑束/生理学动物

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Study of mechanical motions in the basal region of the chinchilla cochlea

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JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2000年第6期107卷 3317-3332页

作者： Rhode, WS Recio, A Univ Wisconsin Dept Physiol Madison WI 53706 USA

Measurements from the 1-4-mm basal region of the chinchilla cochlea indicate the basilar membrane in the hook region (12-18 kHz) vibrates essentially as it does more apically, in the 5-9-kHz region. That is, a compressive nonlinearity in the region of the characteristic frequency, amplitude-dependent phase changes, and a gain relative to stapes motion that can attain nearly 10 000 at low levels. The displacement at threshold for auditory-nerve fibers in this region (20 dB SPL) was similar to 2 nm. Measurements were made at several locations in individual animals in the longitudinal and radial directions. The results indicate that there is little variability in the phase of motion radially and no indication of higher-order modes of vibration. The data from the longitudinal studies indicate that there is a shift in the location of the maximum with increasing stimulus levels toward the base. The cochlear amplifier extends over a 2-3-mm region around the location of the characteristic frequency. (C) 2000 Acoustical Society of America. [S0001-4966(00)01506-X].

关键词：听觉皮质/生理学听阈/生理学基底膜/生理学毛丝鼠属/生理学耳蜗/生理学运动(Movement)/生理学神经纤维/生理学动物

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Electrophysiological assessment of the cutaneous arborization of Aδ-fiber nociceptors

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JOURNAL OF NEUROPHYSIOLOGY 1999年第3期82卷 1164-1177页

作者： Peng, YB Ringkamp, M Campbell, JN Meyer, RA Johns Hopkins Univ Appl Phys Lab Laurel MD 20723 USA Johns Hopkins Univ Dept Neurosurg Laurel MD 20723 USA

Little is known about the relationship between the branching structure and function of physiologically identified cutaneous nociceptor terminals. The axonal arborization itself, however, has an impact on the afferent signal that is conveyed along the parent axon to the CNS. We therefore developed electrophysiological techniques to investigate the branching structure of cutaneous nociceptors. Single-fiber recordings were obtained from physiologically identified nociceptors that innervated the hairy skin of the monkey. Electrodes for transcutaneous stimulation were fixed at two separate locations inside the receptive field. For 32 A delta-fiber nociceptors, distinct steps in latency of the recorded action potential were observed as the intensity of the transcutaneous electrical stimulus increased, indicating discrete sites for action potential initiation. The number of discrete latencies at each stimulation location ranged from I to 9 (3.7 +/- 0.2;mean +/- SE) and the mean size of the latency step was 9.9 +/- 1.0 ms (range: 0.4-89.1 ms). For seven A delta fibers, collision techniques were used to locate the position of the branch point where the daughter fibers that innervated the two locations within the receptive field join the parent axon. To correct for changes in electrical excitability at the peripheral terminals, collision experiments between the two skin locations and between each skin location and a nerve hunk electrode were necessary. Nine branch points were studied in the seven A delta fibers;the mean propagation time from the action potential initiation site to the branch point was 31 +/- 5 ms corresponding to a distance of 54 +/- 10 mm. Almost half of the daughter branches were unmyelinated. These results demonstrate that collision techniques can be used to study the functional anatomy of physiologically identified nociceptive afferent terminals. Furthermore these results indicate that some nociceptive afferents branch quite proximal to their peripheral r

关键词：动作电位/生理学树突/生理学电刺激电生理学直鼻猴亚目神经纤维/生理学神经传导/生理学疼痛感受器/生理学反应时间/生理学不应期电生理学/生理学皮肤/神经支配时间因素动物

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Temporal coupling between neuronal activity and blood flow in rat cerebellar cortex as indicated by field potential analysis

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JOURNAL OF PHYSIOLOGY-LONDON 2000年第1期523卷 235-246页

作者： Mathiesen, C Caesar, K Lauritzen, M NeuroSearch AS DK-2750 Ballerup Denmark Univ Copenhagen Inst Med Physiol Copenhagen Denmark Glostrup Hosp Dept Clin Neurophysiol DK-2600 Glostrup Denmark

1. Laser-Doppler flowmetry and extracellular recordings of field potentials were used to examine the temporal coupling between neuronal activity and increases in cerebellar blood flow (CeBF). 2. Climbing fibre-evoked increases in CeBF were dependent on stimulus duration, indicating that increases in CeBF reflected a time integral in neuronal activity. The simplest way to represent neuronal activity over time was to obtain a running summation of evoked field potential amplitudes (run Sigma FP). Run Sigma FP was calculated for each stimulus protocol and compared with the time course of the CeBF responses to demonstrate coupling between nerve cell activity and CeBF. 3. In the climbing fibre system, the amplitude and time course of CeBF were in agreement with the calculated postsynaptic run Sigma FP (2-20 Hz for 60 s). This suggested coupling between CeBF and neuronal activity in this excitatory, monosynaptic, afferent-input system under these conditions. There was no correlation between run Sigma FP and CeBF during prolonged stimulation. 4. Parallel fibre-evoked increases in CeBF correlated with run Sigma FP of pre- and postsynaptic potentials (2-15 Hz for 60 s). At higher stimulation frequencies and during longer-lasting stimulation the time course and amplitudes of CeBF responses correlated with run Sigma FP of presynaptic, but not postsynaptic potentials. This suggested a more complex relationship in this mixed inhibitory-excitatory, disynaptic, afferent-input system. 5. This study has demonstrated temporal coupling between neuronal activity and CeBF in the monosynaptic, excitatory climbing-fibre system. In the mixed mono- and disynaptic parallel fibre system, temporal coupling was most clearly observed at low stimulation frequencies. We propose that appropriate modelling of electrophysiological data is needed to document functional coupling of neuronal activity and blood flow.

关键词：动作电位/生理学小脑皮质/血液供给小脑皮质/细胞学小脑皮质/生理学脑血管循环/生理学电刺激神经纤维/生理学神经元/生理学大鼠 Wistar 时间因素动物男(雄)性大鼠

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NYSTAGMIC MODULATION OF NEURONAL-ACTIVITY IN RABBIT CEREBELLAR FLOCCULUS

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PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY 1976年第1期367卷 7-13页

作者： LLINAS, R SIMPSON, JI PRECHT, W UNIV IOWA DEPT PHYSIOL & BIOPHYS DIV NEUROBIOL IOWA CITY IA 52242 USA MAX PLANCK INST HIRN FORSCH NEUROBIOL ABT D-6000 FRANKFURT FED REP GER

The responses of neuronal elements in the flocculus of the awake, restrained rabbit were recorded during horizontal vestibular nystagmus in the dark. Purkinje cells showed both vestibular (types I and II) and eye movement modulation of simple spike activity. Type I Purkinje cells most commonly were inhibited in association with the ipsilaterally directed fast phase of nystagmus and excited during contralaterally directed fast phases. Type II Purkinje cells had a similar modulation but in the opposite direction. Variations on this pattern included an increase in firing during fast phases in both directions. Presumed mossy fibers and granule cells also exhibited vestibular and nystagmic modulation in various combinations. The nystagmic modulation often began during the fast phase and continued into the early part of the slow phase. Mossy fibers showing vestibular and nystagmic modulation probably arise from the vestibular nuclei and/or the perihypoglossal nuclei. Floccular control of brain stem nuclei utilizes not only vestibular but also eye movement signals and probably all sensory and internal signals involved in the regulation of gaze.

关键词：小脑皮质/生理学诱发电位眼球运动神经纤维/生理学神经通路/生理学神经元/生理学浦肯野细胞/生理学旋转前庭迷路/生理学动物兔

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Medial efferent effects on auditory-nerve responses to tail-frequency tones. I. Rate reduction

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JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 1999年第2期106卷 857-869页

作者： Stankovic, JM Guinan, JJ Massachusetts Eye & Ear Infirm Dept Otolaryngol Eaton Peabody Lab Autitory Physiol Boston MA 02114 USA MIT Harvard Mit Div Hlth Sci & Technol Cambridge MA 02139 USA MIT Elect Res Lab Cambridge MA 02139 USA Harvard Univ Sch Med Dept Otol & Laryngol Boston MA 02115 USA

One way medial efferents are thought to inhibit responses of auditory-nerve fibers (ANFs) is by reducing the gain of the cochlear amplifier thereby reducing motion of the basilar membrane. If this is the only mechanism of medial efferent inhibition, then medial efferents would not be expected to inhibit responses where the cochlear amplifier has little effect, i.e., at sound frequencies in the tails of tuning curves. Inhibition at tail frequencies was tested for by obtaining randomized rate-level functions from cat ANFs with high characteristic frequencies (CF greater than or equal to 5 kHz), stimulated with tones two or more octaves below CF. It was found that electrical stimulation of medial efferents can indeed inhibit ANF responses to tail-frequency tones. The amplitude of efferent inhibition depended on both sound level (largest near to threshold) and frequency (largest two to three octaves below CF). On average, inhibition of high-CF ANFs responding to 1 kHz tones was around 5 dB. Although an efferent reduction of basilar-membrane motion cannot be ruled out as the mechanism producing the inhibition of ANF responses to tail frequency tones, it seems more likely that efferents produce this effect by changing the micromechanics of the cochlear partition. (C) 1999 Acoustical Society of America. [S0001-4966(99)00908-X].

关键词：声刺激/方法基底膜/生理学耳蜗/生理学电刺激/方法神经纤维/生理学神经元传出/生理学声音前庭耳蜗神经/生理学动物猫

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Effects of intracolonic opioid receptor agonists on polymodal pelvic nerve afferent fibers in the rat

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JOURNAL OF NEUROPHYSIOLOGY 2000年第2期83卷 963-970页

作者： Su, X Julia, V Gebhart, GF Univ Iowa Coll Med Dept Pharmacol Iowa City IA 52242 USA

Effects of intracolonic opioid receptor agonists on polymodal pelvic nerve afferent fibers in the rat. J. Neurophysiol. 83: 963-970, 2000. We studied the effects of intra colonic administration of opioid receptor agonists (ORAs) on responses of pelvic nerve efferent fibers to colorectal distension (CRD) and heat. Single-fiber recordings were made from the decentralized S1 dorsal rootlet in the rat. An similar to 7-cm length of descending colon was isolated in situ to permit intracolonic perfusion with Krebs solution, which, when the outflow was clamped, was used to distend the colon. Responses to noxious CRD (40 mmHg, 30 s) were tested after intracolonic instillation of mu-, delta- or kappa-ORAs. Intracolonic administration of the kappa-ORAs EMD 61,753 (n = 5/12) and U62,066 (n = 8/11), but not either the mu-ORA fentanyl or the delta-ORA SNC-80, concentration-dependently inhibited responses of afferent fibers. For fibers unaffected by intracolonic administration of EMD 61,753 or U62,066, intra-arterial administration of kappa-ORAs was effective. Forty-one of 54 mechanosensitive fibers also responded to intracolonic instillation of heated Krebs solution (50 degrees C). Intra-arterial injection of fentanyl or SNC-80 did not attenuate responses to heat. Either intracolonic or intra-arterial administration of EMD 61,753 or U62,066, however, inhibited afferent fiber responses to heat. These results document that mechanical and thermal sensitivity of polymodal pelvic nerve afferent fibers innervating the rat colon can be inhibited peripherally by intracolonic instillation of kappa-ORAs.

关键词：乙酰胺类/药理学镇痛药/药理学镇痛药阿片类/药理学苯甲酰胺类/药理学结肠/神经支配芬太尼/药理学热温度纳洛酮/药理学麻醉品拮抗药/药理学神经纤维/化学神经纤维/生理学神经元传入/化学神经元传入/药物作用神经元传入/超微结构周围神经/化学周围神经/药物作用周围神经/生理学物理刺激哌嗪类/药理学压力吡咯烷类/药理学大鼠 Sprague-Dawley 受体阿片样 κ/激动剂脊神经根/细胞学动物男(雄)性大鼠

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PROXIMAL LIMB MOVEMENTS IN RESPONSE TO MICROSTIMULATION OF PRIMATE DENTATE AND INTERPOSITUS NUCLEI MEDIATED BY BRAIN-STEM STRUCTURES

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BRAIN 1979年第MAR期102卷 127-146页

作者： SCHULTZ, W MONTGOMERY, EB MARINI, R WASHINGTON UNIV SCH MED DEPT NEUROL ST LOUIS MO 63110 USA SUNY BUFFALO SCH MED DEPT PHYSIOL NEUROBIOL LAB BUFFALO NY 14214 USA

The cerebellar dentate and interpositus nuclei and the area of their efferent fibres have been stimulated in Cebus monkeys, using a movable microcathode. Responses consisted of eye and face movements and a stereotyped flexion of proximal parts of extremities. Very few distal limb movements were seen. The activation of proximal muscles was studied most closely. It consisted of the limited number of 5 movements: arm flexion and shoulder elevation in the forelimb and hip flexion, knee flexion and dorsiflexion of the ankle in the hindlimb. With currents of up to 100 microamperemeter these movements were elicited more readily from the interpositus and the area of efferent fibres of both nuclei as compared to the dentate nucleus. Responses were more often seen in forelimb than in hindlimb muscles, without apparent somatotopy in either nucleus. Combined forelimb-hindlimb movements were elicited from 42 per cent of effective points. Lesions placed at various locations of cerebellar output pathways demonstrated that the responses were mediated by the descending branch of brachium conjunctivum and did not require the activation of structures anterior to and including the red nucleus. The responses are interpreted to represent adjustments in flexor posture that may serve to modify maintained antigravity tonus during the initiation of volitional movements. This function, mediated by brain-stem structures, is considered to be closely associated with the activity of the lateral and intermediate cerebellum during initiation and conduction of volitional movements, which is mediated mainly through the cerebral cortex. It is stressed that control over both flexor posture and discrete distal movements is inherent in the initiation of voluntary movements.

关键词：脑图脑干/生理学小脑核/生理学大脑皮质/生理学传出通路/生理学电刺激前肢/神经支配直鼻猴亚目后肢/神经支配运动皮质/生理学运动(Movement) 肌收缩神经纤维/生理学体位脊髓/生理学动物

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