101
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Malagodi MS, Horch KW, Schoenberg AA. An intrafascicular electrode for recording of action potentials in peripheral nerves. Ann Biomed Eng 1989; 17:397-410. [PMID: 2774314 DOI: 10.1007/bf02368058] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We are developing a new type of bipolar recording electrode intended for implantation within individual fascicles of mammalian peripheral nerves. In the experiments reported here we used electrodes fabricated from 25 microns diameter Pt wire, 50 microns 90% Pt-10% Ir wire and 7 microns carbon fibers. The electrodes were implanted in the sciatic nerves of rats and in the ulnar nerves of cats. The signal-to-noise ratio of recorded activity induced by nonnoxious mechanical stimulation of the skin and joints was studied as a function of the type of electrode material used, the amount of insulation removed from the recording zone, and the longitudinal separation of the recording zones of bipolar electrode pairs. Both acute and short term (two day) chronic experiments were performed. The results indicate that a bipolar electrode made from Teflon-insulated, 25 microns diameter, 90% Pt-10% Ir wire, having a 1-2 mm long recording zone, can be used for recording of peripheral nerve activity when implanted with one wire inside the fascicle and the other lead level with the first lead, but outside the fascicle. No insulating cuff needs to be placed around the nerve trunk.
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Affiliation(s)
- M S Malagodi
- Department of Bioengineering, University of Utah, Salt Lake City 84112
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102
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103
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Kodama T, Mushiake H, Shima K, Nakahama H, Yamamoto M. Slow fluctuations of single unit activities of hippocampal and thalamic neurons in cats. I. Relation to natural sleep and alert states. Brain Res 1989; 487:26-34. [PMID: 2752287 DOI: 10.1016/0006-8993(89)90936-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Spontaneous unit discharges during the natural sleep-wakefulness cycle in two different neuronal groups, the hippocampal pyramidal cells and thalamic ventrobasal neurons, have been analyzed. The results show that both neurons fire with white-noise-like fluctuations during the slow-wave sleep, and with slow fluctuations with power spectral densities inversely proportional to the frequency in the frequency range of 0.02-1.0 Hz, during the paradoxical sleep. This confirms that the characteristics of fluctuations in neuronal activities of the mesencephalic reticular formation observed in our previous study are more general phenomena in the cat's brain. Partly similar behavior of spectral densities is also observed during the alert state. These observations are quantitatively confirmed by the statistical time series analysis of the spike density processes of spontaneous activities.
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Affiliation(s)
- T Kodama
- Department of Neurophysiology, Tohoku University School of Medicine, Sendai, Japan
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104
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Schmidt EM, McIntosh JS, Bak MJ. Long-term implants of Parylene-C coated microelectrodes. Med Biol Eng Comput 1988; 26:96-101. [PMID: 3199908 DOI: 10.1007/bf02441836] [Citation(s) in RCA: 117] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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105
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Glotzbach SF, Cornett CM, Heller HC. Activity of suprachiasmatic and hypothalamic neurons during sleep and wakefulness in the rat. Brain Res 1987; 419:279-86. [PMID: 3676731 DOI: 10.1016/0006-8993(87)90594-4] [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
Single unit activity was recorded from the suprachiasmatic nucleus (SCN) and preoptic/anterior hypothalamus (POAH) of unrestrained Wistar rats during sleep and wakefulness. Regularly firing cells, which are abundant in in vitro SCN preparations and have been considered the basis of a central neuronal oscillator, were conspicuously absent in this preparation and in other in vivo studies. Most of the 55 cells recorded in the SCN and POAH were characterized by spontaneous firing rates below 12 Hz and with heterogeneous patterns of changes in frequency with arousal states. In vivo neurophysiological studies of the SCN in which the anesthetic agent urethane is used should consider the effect of different levels of arousal, as indicated by the cortical EEG, in evaluating the relationship between sensory stimulation and single unit activity.
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Affiliation(s)
- S F Glotzbach
- Department of Biological Sciences, Stanford University, CA 94305
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106
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Diana M, Garcia-Munoz M, Freed CR. Wire electrodes for chronic single unit recording of dopamine cells in substantia nigra pars compacta of awake rats. J Neurosci Methods 1987; 21:71-9. [PMID: 3657271 DOI: 10.1016/0165-0270(87)90103-8] [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: 01/06/2023]
Abstract
Stainless steel wire electrodes of varying sizes and coated with different insulating materials were tested in order to find a flexible fine wire which would allow the recording of small cells in deep structures of the brain in unrestrained, awake rats. Our main interest is to record from cells of substantia nigra pars compacta during locomotion. We found that stress relieved 18 micron stainless steel wire doubly insulated with lacquer and Parylene C provided the impedance, physical size, and flexibility needed to record single units during intense motor behavior.
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Affiliation(s)
- M Diana
- Division of Clinical Pharmacology, University of Colorado Health Sciences Center, Denver 80262
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107
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Shima K, Nakahama H, Yamamoto M, Aya K, Inase M. Effects of morphine on two types of nucleus raphe dorsalis neurons in awake cats. Pain 1987; 29:375-386. [PMID: 3614972 DOI: 10.1016/0304-3959(87)90052-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Forty-nine neurons recorded within the nucleus raphe dorsalis (NRD) in awake cats were classified into 2 groups: 29 regularly firing (clock-like) and 20 irregularly firing (non-clock-like) neurons. Hardly any of the clock-like neurons were influenced either by noxious stimulation (0.1 ml of 5% formalin, s.c.) or by a single dose (1 mg/kg, i.p.) or cumulative doses (0.25, 0.5, 1 mg/kg) of morphine. In contrast, about half the non-clock-like neurons were activated both by noxious stimulation and by administration of morphine. Morphine-induced activation of non-clock-like neurons was dose-related and reversed by naloxone (0.2 mg/kg, i.p.). These findings suggest that clock-like neurons in the NRD are not involved in morphine analgesia. Non-clock-like neurons, however, may play a role in the mediation of such analgesia.
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Affiliation(s)
- Keisetsu Shima
- Division of Neurophysiology, Institute of Brain Diseases, Tohoku University School of Medicine, Sendai 980 Japan
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108
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Shima K, Nakahama H, Yamamoto M. Firing properties of two types of nucleus raphe dorsalis neurons during the sleep-waking cycle and their responses to sensory stimuli. Brain Res 1986; 399:317-26. [PMID: 3828768 DOI: 10.1016/0006-8993(86)91522-2] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Spontaneous activity of the nucleus raphe dorsalis (NRD) neurons during the sleep-waking cycle and effects of sensory stimuli upon NRD neurons were studied in cats. Seventy-one neurons recorded within the NRD were classified into two groups with the use of the coefficient of variation of firing intervals during waking (W): 41 regularly firing (clock-like) and 30 irregularly firing (non-clock-like) neurons. The majority of clock-like and one-third of non-clock-like neurons showed a decrease in their firing rate during slow-wave sleep (SWS) compared with W. All neurons of both types displayed their lowest level of activity during paradoxical sleep. During the late phase of SWS, many clock-like neurons reduced their firing prior to the occurrence of pontogeniculo-occipital waves, whereas non-clock-like neurons did not show such a specific property. Clock-like neurons were totally unresponsive to nociceptive and non-nociceptive somesthetic stimuli, while about half of the non-clock-like neurons were driven by these stimuli. Half of the clock-like and one-third of the non-clock-like neurons were driven by click stimulation, and the majority of them showed an excitatory response. Some of the clock-like and non-clock-like neurons exhibited inhibitory and excitatory response to flash stimulation, respectively. The results of this experiment show that two types of neurons do exist in the NRD and suggest that they play a functionally different role in the brain.
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109
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Levy BP, Campbell SL, Rose TL. Definition of the geometric area of a microelectrode tip by plasma etching of Parylene. IEEE Trans Biomed Eng 1986; 33:1046-9. [PMID: 3793126 DOI: 10.1109/tbme.1986.325872] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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110
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Yamamoto M, Nakahama H, Shima K, Kodama T, Mushiake H. Markov-dependency and spectral analyses on spike-counts in mesencephalic reticular neurons during sleep and attentive states. Brain Res 1986; 366:279-89. [PMID: 3697684 DOI: 10.1016/0006-8993(86)91305-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Spontaneous activities of the mesencephalic reticular formation (MRF) neurons of head-restrained cats were recorded to investigate their dynamic properties during sleep and waking. The Markov-dependency and spectral analyses were performed on the time series of counts converted from the MRF spike-train. During slow-wave sleep (SWS), MRF neurons fired with low Markovian properties and had a similar spectral-density curve as white noise; during paradoxical sleep (PS), their firing pattern showed high Markovian properties owing to low-frequency fluctuations, with spectral densities inversely proportional to frequency (the l/f spectrum). During the attentive state of bird watching (BW), intermediate Markovian properties were observed. These results confirmed both the rest theory of SWS and the activation of the brain during PS from the viewpoint of dynamic information-processing. Furthermore, the activation of the brain during PS may be greater than in BW.
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111
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112
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Abstract
Capacitor electrodes offer the potential for the safest method of stimulation of neural tissue because they operate without any faradaic process occurring at the electrode-electrolyte interface. Their use eliminates problems associated with metal dissolution or water electrolysis which may occur with electrodes of noble metals. This paper reviews recent work aimed at increasing the charge storage density of capacitor electrodes to allow their application with the small areas of 10(-4) mm2 required for intracortical stimulation of single neurons. Increased charge storage with electrodes using anodic films such as TiO2 and Ta2O5 has been obtained by increasing the real surface area of microelectrodes. Experiments have also been done with BaTiO3 films which have a much higher dielectric constant than the anodic film dielectrics. State-of-the-art electrodes made with these materials, however, have a charge storage density which at best is comparable to that obtained with Pt and is considerably lower than electrochemically safe charge densities that have been reported for activated Ir. It is concluded that for very small intracortical electrodes, capacitor electrodes will not be competitive with electrodes which operate using surface localized faradaic reactions.
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113
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Rindos AJ, Loeb GE, Levitan H. Conduction velocity changes along lumbar primary afferent fibers in cats. Exp Neurol 1984; 86:208-26. [PMID: 6489495 DOI: 10.1016/0014-4886(84)90182-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Though peripheral conduction velocity is widely used to characterize afferent fibers according to somatosensory modality, disagreement exists as to whether or not conduction velocity varies along such an axon's length. Therefore, in this experiment, conduction velocities were measured over very short axonal segments (7.5 to 15 mm) within the posterior tibial nerve, sciatic nerve, and L7 dorsal root, using the method of spike-triggered averaging of neurograms recorded from tripolar electrodes. The conduction velocities for several units were also determined using electrical stimulation, so that the accuracy of the two techniques could be compared. For most units, dorsal root and sciatic nerve conduction velocities were not significantly different; however, they were not tightly correlated. Tibial nerve conduction velocity averaged 86% of that within the sciatic nerve. Variations in sciatic nerve conduction velocity within adjacent axonal segments (9 mm in length) rarely exceeded experimental error. It appears that spike-triggered averaging of signals from tripolar electrodes separated 15 mm or more apart is a more accurate method for measuring conduction velocity than electrical stimulation, which was subject to several large errors.
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114
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Legéndy CR, Salcman M, Brennan N. A multiple floating microelectrode for chronic implantation and longterm single unit recording in the cat. ELECTROENCEPHALOGRAPHY AND CLINICAL NEUROPHYSIOLOGY 1984; 58:285-8. [PMID: 6205861 DOI: 10.1016/0013-4694(84)90115-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
This paper describes a multiple electrode, suitable for chronic implantation and single unit recording in the superficial cerebral cortex of the cat. The electrodes are fine wires, 5-8 per implant, not kept together in a bundle; a segment of them floats freely in saline in a closed chamber over the place of penetration. The electrode tips are not sharpened electrolytically, but cut at a bevel during surgery. Longevity of the implants is improved by slowing down the occasional rapid head shaking characteristic of cats, which tends to tear out implanted electrodes, by means of a small weight attached by a bar to the head.
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115
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Glotzbach SF, Heller HC. Changes in the thermal characteristics of hypothalamic neurons during sleep and wakefulness. Brain Res 1984; 309:17-26. [PMID: 6488008 DOI: 10.1016/0006-8993(84)91006-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The characteristics of the mammalian thermoregulatory system are dependent upon arousal state. During NREM sleep thermoregulatory mechanisms are intact but body temperature is regulated at a lower level than during wakefulness. In REM sleep thermoregulatory effector mechanisms are inhibited and thermal homeostasis is severely disrupted. Thermosensitivity of neurons in the preoptic/anterior hypothalamus (POAH) was determined for behaving kangaroo rats (Dipodomys deserti) during electrophysiologically defined wakefulness, NREM sleep and REM sleep to elucidate possible neural mechanisms for previous findings of state-dependent changes in thermoregulation. Thirty cells were tested during at least two arousal states. During wakefulness, 70% of the recorded cells were sensitive to changes in local temperature, with the number of warm-sensitive (W) cells outnumbering cold-sensitive (C) cells by 1.6:1. In NREM sleep, 43% of the cells were thermally sensitive, with the ratio of W:C remaining the same as in wakefulness. In REM sleep only two cells were thermosensitive (both W). The decrease in neuronal thermosensitivity of POAH cells during REM sleep parallels findings of inhibition of thermoregulatory effector responses during REM, although further work is necessary to determine the source and nature of the inhibition.
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116
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Loeb GE, Byers CL, Rebscher SJ, Casey DE, Fong MM, Schindler RA, Gray RF, Merzenich MM. Design and fabrication of an experimental cochlear prosthesis. Med Biol Eng Comput 1983; 21:241-54. [PMID: 6688284 DOI: 10.1007/bf02478489] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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117
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O'Donovan MJ, Hoffer JA, Loeb GE. Physiological characterization of motor unit properties in intact cats. J Neurosci Methods 1983; 7:137-49. [PMID: 6300565 DOI: 10.1016/0165-0270(83)90076-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Single motor units were isolated in intact cats, by microstimulation through chronically implanted microwires in the L5 ventral roots. Motor unit axonal and mechanical properties were obtained by stimulus-triggered averaging the signals from an implanted femoral nerve recording cuff and patellar tendon force transducer. All unit types were sampled with this technique, and it was also possible to stimulate in isolation an axon whose ventral root spike was recorded during treadmill locomotion. A new technique was described, spike-triggered microstimulation, for verifying the identity of a stimulated and a recorded axon.
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118
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Pollen DA, Ronner SF. Spatial computation performed by simple and complex cells in the visual cortex of the cat. Vision Res 1982; 22:101-18. [PMID: 7101735 DOI: 10.1016/0042-6989(82)90172-9] [Citation(s) in RCA: 95] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Simple and complex cells have been tested with drifting sine-wave and square-wave gratings. Despite the known differences in the response pattern of each cell type to drifting sine-wave gratings, the tuning curves for square-wave gratings for both cell types show a similar secondary response band peaking at one-third the preferred spatial frequency as determined from sine-wave studies. These results establish that both cell types respond predominantly to the third harmonic of square-wave gratings in this frequency range. At the simple cell stage, all the information required to specify the amplitude and phase for channel at a given orientation, direction and spatial frequency can be conveyed by four cells for a given subsection of visual space. At the complex cell stage, the cell's mean firing rate appears to represent the amplitude of a local Fourier coefficient, but phase information is not conveyed in the action potential code.
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119
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Schmidt EM, Hambrecht FT, McIntosh JS. Intracortical capacitor electrodes: preliminary evaluation. J Neurosci Methods 1982; 5:33-9. [PMID: 7057683 DOI: 10.1016/0165-0270(82)90048-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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120
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Hoffer JA, Loeb GE, Pratt CA. Single unit conduction velocities from averaged nerve cuff electrode records in freely moving cats. J Neurosci Methods 1981; 4:211-25. [PMID: 7300428 DOI: 10.1016/0165-0270(81)90033-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The conduction velocity of peripheral neurons recorded by wire microelectrodes implanted in intact, freely moving cats was determined on-line using the technique of spike-triggered averaging of nerve cuff electrode records described here. Axonal velocity was estimated from the conduction latency between two adjacent sets of tripolar recording electrodes inside a cuff, thereby avoiding uncertainties that could arise from differences in spike shape, variable conduction distance, or unknown stimulus utilization time. This method rendered conduction velocity values for individual afferent and efferent myelinated fibers ranging from 27 to 120 m/sec, estimated with an uncertainty of +/-5%. In addition, predictions from theoretical models relating extracellular potential amplitude, wavelength, and conduction velocity were confirmed experimentally for en passant records obtained from intact myelinated fibers.
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121
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Guilbeau EJ, Mayall BI. Microthermocouple for soft tissue temperature determination. IEEE Trans Biomed Eng 1981; 28:301-5. [PMID: 7228077 DOI: 10.1109/tbme.1981.324706] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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122
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Abstract
A method for insulating tungsten wires with glass by collapsing a glass capillary tube around the wire is described. A common laboratory electrode puller can be used. A new method for removing the glass from the tip using hydrofluoric acid is also described.
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123
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Schmidt EM. Single neuron recording from motor cortex as a possible source of signals for control of external devices. Ann Biomed Eng 1980; 8:339-49. [PMID: 6794389 DOI: 10.1007/bf02363437] [Citation(s) in RCA: 82] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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124
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Hoffer JA, Loeb GE. Implantable electrical and mechanical interfaces with nerve and muscle. Ann Biomed Eng 1980; 8:351-60. [PMID: 7027837 DOI: 10.1007/bf02363438] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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125
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126
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Part 8. References. The Journal of Laryngology & Otology 1978. [DOI: 10.1017/s0022215100085066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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127
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128
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129
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Loeb GE. Decreased conduction velocity in the proximal projections of myelinated dorsal root ganglion cells in the cat. Brain Res 1976; 103:381-5. [PMID: 1252927 DOI: 10.1016/0006-8993(76)90810-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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