1 - 25 of 14
| Creator | Title | Description | Subject | Date | ||
|---|---|---|---|---|---|---|
| 1 |
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Normann, Richard A.; Shoham, Shy | Coding of position by simultaneously recorded sensory neurones in the cat dorsal root ganglion | Muscle, cutaneous and joint afferents continuously signal information about the position and movement of individual joints. How does the nervous system extract more global information, for example about the position of the foot in space? To study this question we used microelectrode arrays to record... | Cats; Sensory Neurones; Movement; Limb Position | 2004 |
| 2 |
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Normann, Richard A. | Functional reorganization of primary visual cortex induced by electrical stimulation in the cat. | Compared to the high degree of plasticity observed in a juvenile, mature sensory cortices have long been held to be immutable but, recently, researchers have suggested some plasticity persists in the mature cortex. Cortical reorganization has particular saliency to the development of a cortically ba... | Cat; Electrophysiology; Phosphene; Plasticity; Receptive Field; Striate Cortex | 2005 |
| 3 |
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Normann, Richard A. | Statistical encoding model for a primary motor cortical brain-computer interface | A number of studies of the motor system suggest that the majority of primary motor cortical neurons represent simple movement-related kinematic and dynamic quantities in their time-varying activity patterns. An example of such an encoding relationship is the cosine tuning of firing rate with respect... | Discrete Distribution; LN Model; Neural Decoding; Neuroprosthetics; Sequential Monte-Carlo Filter | 2005 |
| 4 |
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Normann, Richard A.; Chandler, John P. | Effects of calcium ions on L-type horizontal cells in the isolated turtle retina | A technique by which the retina can be isolated from the turtle eye is described. Scanning electron microscopy revealed morphological variability between preparations and also between regions of the same one. Large areas were often totally free of any pigment epithelial cells, yet contained a high p... | Retina; Calcium; Horizontal Cell; Turtle | 1990 |
| 5 |
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Normann, Richard A. | Effects of GABA and related drugs on horizontal cells in the isolated turtle retina | The role of GABA in the outer plexiform layer of the turtle retina has been examined by intracellular recordings from L- and C-type horizontal cells in the isolated retina preparation. GABA (1-5 mM) slightly depolarized the L-type horizontal cells, reduced the amplitude of their photoresponses, and ... | Retina; Horizontal Cells; Synapse; Negative Feedback; GABA; Turtle | 1990 |
| 6 |
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Normann, Richard A. | Control of retinal sensitivity. I. Light and dark adaptation of vertebrate rods and cones | Rods and cones in Necturus respond with graded hyperpolarization to test flashes spanning about 3.5 log units of intensity. Steady background levels hyperpolarize the rods, and the rod responses become progressively smaller as background level is increased. In cones, higher background levels reduce... | Retina;Light and Dark Adaptation; Recepters; Bipolars; Ganglion Cells | 1974 |
| 7 |
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Normann, Richard A.; Jones, Kelly E. | Advanced demultiplexing system for physiological stimulation | A CMOS very large scale integration (VLSI) chip has been designed and built to implement a scheme developed for multiplexing/demultiplexing the signals required to operate an intracortical stimulating electrode array. Because the use of radio telemetry in a proposed system utilizing this chip may im... | Electrode Array; Stimulation; Telemetry; Microelectrodes; Transistors | 1997 |
| 8 |
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Normann, Richard A.; Shoham, Shy | Encoding mechanisms for sensory neurons studied with a multielectrode array in the cat dorsal root ganglion | Recent advances in microelectrode array technology now permit a direct examination of the way populations of sensory neurons encode information about a limb's position in space. To address this issue, we recorded nerve impulses from about 100 single units simultaneously in the L6 and L7 dorsal root ... | Sensory; Encoding; Multielectrode; Dorsal Root Ganglion; Cutaneour; Muscle | 2004 |
| 9 |
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Lucero, Mary T.; Mobley, Arie S. | Cross-species comparison of metabolite profiles in chemosensory epithelia: an indication of metabolite roles in chemosensory cells | Comparative studies of chemosensory systems in vertebrates and invertebrates have greatly enhanced our understanding of anatomical and physiological constraints of chemical detection. Immunohistochemical comparisons of chemosensory systems are difficult to make across species due to limited cross-re... | Olfactory; Vomeronasal; Mouse; Zebrafish; Squid | 2008-04 |
| 10 |
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Normann, Richard A. | Visual Neuroprosthetics: Functional Vision for the Blind | Resent progress in materials and microfabrication technologies have allowed researchers to reconsider the prospect of providing a useful visual sense to the profoundly blind. This will be accomplished by electrically stimulating their visual systems via an array of implanted microelectrodes. T... | Visual Neuroprosthetics; Vision; Blindness | 1995-01 |
| 11 |
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Normann, Richard A.; Clark, Gregory A.; McDonnall, Daniel | Selective motor unit recruitment via intrafascicular multielectrode stimulation | Recruitment of force via independent asynchronous firing of large numbers of motor units produces the grace and endurance of physiological motion. We have investigated the possibility of reproducing this physiological recruitment strategy by determining the selectivity of access to large numbers of ... | Funtional Neuromuscular Stimulation; Microelectrode Array; Neuroprosthesis; Intrafascicular Multielectrode Stimulation; Cats | 2004 |
| 12 |
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Normann, Richard A.; Kolb, Helga; Lasater, Eric M. | Signal integration at the pedicle of turtle cone photoreceptors: an anatomical and electrophysiological study | The morphology of the axon which connects the cell body and pedicle of turtle cone photoreceptors was studied by light and electron microscopy. The axon which contains numerous synaptic vesicles, some endoplasmic reticulum, and a few cisternae is basically filled with cytoplasm. The length of the ax... | Cone Photoreceptor, Voltage Clamp; Isolated Cells; Input Resistance; Cell Body-Pedicle Coupling | 1989 |
| 13 |
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Normann, Richard A.; Maynard, Edwin M. | Neuronal interactions improve cortical population coding of movement direction | Interactions among groups of neurons in primary motor cortex (MI) may convey information about motor behavior. We investigated the information carried by interactions in MI of macaque monkeys using a novel multielectrode array to record simultaneously from 12-16 neurons during an arm-reaching task. ... | Motor Cortex; Monkey; Population Coding; Movement | 1999 |
| 14 |
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Normann, Richard A.; Muller, Jay F.; Kolb, Helga | Synaptic inputs to physiologically defined turtle retinal ganglion cells | Two physiologically distinct, HRP-marked turtle retinal ganglion cells were examined for their morphology, GABAergic, glycinergic, and bipolar cell synaptic inputs, using electron-microscopic autoradiography and postembedding immunocytochemistry. One cell was a color-opponent, transient ON/OFF gangl... | Turtles; Neural Pathways; Synapes; Retinal Ganglion Cells | 1991 |
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