Chronic paw denervation causes an age-dependent appearance of novel responses from forearm in "paw cortex" of kittens and adult cats

1979 ◽  
Vol 42 (2) ◽  
pp. 618-633 ◽  
Author(s):  
J. Kalaska ◽  
B. Pomeranz
Keyword(s):  
Electrical Stimulation ◽  
Peripheral Nerve Injury ◽  
Receptive Fields ◽  
Similar Process ◽  
Nerve Injuries ◽  
Somatotopic Organization ◽  
Natural Stimulation ◽  
Age Dependent ◽  
Adult Cats ◽  
Stimulation Of

1. In normal kittens and cats, cells in a region of primary somatosensory cortex (SI) responded exclusively to input from the contralateral front paw; we called this area paw cortex (PC). A neighboring region of SI responded to input from the contralateral forearm above the wrist; we called this area forearm cortex (FC). The centers of PC and FC were about 4 mm apart. 2. In kittens several weeks after transection of the nerves to the front paw, the following changes were observed in PC: a) 52% of PC cells had receptive fields on the forearm; normally, PC cells responded to natural stimulation only of the front paw; b) many cells in PC (58%) responded to electrical stimulation of the medial cutaneous nerve from the forearm; normally, very few PC cells (9%) responded to this nerve; c) there was a 370% increase in the median amplitude of medial cutaneous-evoked potentials in PC; d) in contrast to these enhanced inputs, PC responses to ulnar nerve stimulation decreased significantly. 3. In adult cats, paw denervation initiated a similar process as in kittens, but with less marked somatotopic changes. 4. In both kittens and adults, FC was unaffected by the nerve injuries. 5. We conclude that a chronic peripheral nerve injury can produce extensive changes in SI cortex somatotopic organization; the nature of the effect is age dependent.

Reorganization of the Raccoon Cuneate Nucleus After Peripheral Denervation

1997 ◽  
Vol 78 (6) ◽  
pp. 2924-2936 ◽  
Author(s):  
Douglas D. Rasmusson ◽  
Stacey A. Northgrave
Keyword(s):  
Electrical Stimulation ◽  
Receptive Fields ◽  
Response Probability ◽  
Dorsal Column ◽  
Cuneate Nucleus ◽  
Intact Control ◽  
Somatotopic Organization ◽  
Low Threshold ◽  
Single Unit Recordings ◽  
Stimulation Of

Rasmusson, Douglas D. and Stacey A. Northgrave. Reorganization of the raccoon cuneate nucleus after peripheral denervation. J. Neurophysiol. 78: 2924–2936, 1997. The effects of peripheral nerve transection on the cuneate nucleus were studied in anesthetized raccoons using extracellular, single-unit recordings. The somatotopic organization of the cuneate nucleus first was examined in intact, control animals. The cuneate nucleus in the raccoon is organized with the digits represented in separate cell clusters. The dorsal cap region of the cuneate nucleus contains a representation of the claws and hairy skin of the digits. Within the representation of the glabrous skin, neurons with rapidly adapting properties tended to be segregated from those with slowly adapting properties. The representations of the distal and proximal pads on a digit also were segregated. Electrical stimulation of two adjacent digits provided a detailed description of the responses originating from the digit that contains the tactile receptive field (the on-focus digit) and from the adjacent (off-focus) digit. Stimulation of the on-focus digit produced a short latency excitation in all 99 neurons tested, with a mean of 10.5 ms. These responses had a low threshold (426 μA). Stimulation of an off-focus digit activated 65% of these neurons. These responses had a significantly longer latency (15.3 ms) than on-focus responses and the threshold was more than twice as large. Two to five months after amputation of digit 4, 97 cells were tested with stimulation of digits 3 and 5. A total of 44 were in the intact regions of the cuneate nucleus. They had small receptive fields on intact digits and their responses to electrical stimulation did not differ from the control neurons. The remaining 53 neurons were judged to be deafferented and in the fourth digit region on the basis of their location with respect to intact neurons. All but two of these cells had receptive fields that were much larger than normal, often including more than one digit and part of the palm. When compared with the off-focus control neurons, their responses to electrical stimulation had lower thresholds and an increased response probability and magnitude. The latencies of these cells did not decrease, however, and were the same as the off-focus control values. The enhanced responses of the deafferented neurons to adjacent digit stimulation indicate that there is a strengthening of synapses that were previously ineffective. The increased proportion of neurons that could be activated after amputation suggests that there is also a growth of new connections. This experiment demonstrates that reorganization in the adult somatotopic system does occur at the level of the dorsal column nuclei. As a consequence, many of the changes reported at the cortex and thalamus may be due to the changes occurring at this first synapse in the somatosensory pathway.

Mechanoafferent neurons innervating tail of Aplysia. I. Response properties and synaptic connections

1983 ◽  
Vol 50 (6) ◽  
pp. 1522-1542 ◽  
Author(s):  
E. T. Walters ◽  
J. H. Byrne ◽  
T. J. Carew ◽  
E. R. Kandel
Keyword(s):  
Electrical Stimulation ◽  
Receptive Field ◽  
Motor Neurons ◽  
Action Potentials ◽  
Receptive Fields ◽  
The Body ◽  
Tail Region ◽  
Withdrawal Reflex ◽  
Somatotopic Organization ◽  
Stimulation Of

Mechanical, chemical, or electrical stimulation of the tail elicits a short-latency (less than 1 s) tail-withdrawal reflex that is graded with the intensity of the stimulus. The tail-withdrawal reflex is not elicited by stimulation of parts of the body outside of the tail region. Mechanoafferent neurons innervating the tail are located in a small subcluster within a large, homogeneous group of medium-size (40-80 micron) cells on the ventrocaudal (VC) surface of each pleural ganglion. The tail sensory neurons within this large VC cluster are activated by tactile pressure or by electrical stimulation of discrete regions of the tail. They adapt slowly to maintained stimulation and sometimes respond to stimulus offset as well. Both mechanical and electrical stimuli produce responses that are graded with the intensity of the stimulus. Cells in the VC cluster appear to be primary mechanoreceptors because they have axons in peripheral nerves (including nerves innervating the tail), they exhibit action potentials lacking prepotentials in response to tactile stimulation, and these action potentials are still produced by cutaneous stimulation when peripheral and central chemical synaptic transmission is blocked. Stimulation of fields all over the body surface evokes synaptically mediated hyperpolarizing responses in individual mechanoafferent neurons that may represent afferent inhibition. Hyperpolarizing responses lasting many seconds can be produced by brief cutaneous stimuli. The mechanoafferent neurons innervating the tail region make strong monosynaptic connections to tail motor neurons in the ipsilateral pedal ganglion, and through these connections this subpopulation of the VC neurons appears to make a substantial contribution to the short-latency tail-withdrawal reflex. In addition, the combined excitatory receptive fields of these mechanoafferents match the excitatory receptive field of the tail-withdrawal reflex. Mechanoafferent neurons in the VC cluster that have receptive fields on other parts of the body (outside the excitatory receptive field of the tail-withdrawal reflex) have not been observed to make monosynaptic connections to the tail motor neurons. The neurons innervating the tail are reliably found in a discrete region within the larger VC cluster. In addition to this gross somatotopic organization, there is evidence of a finer level of somatotopic organization between the position of the excitatory receptive field on the tail and the position of the cell soma in the tail subcluster.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Electrical stimulation of the nucleus basalis of meynert: a systematic review of preclinical and clinical data

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Muhammad Nazmuddin ◽  
Ingrid H. C. H. M. Philippens ◽  
Teus van Laar
Keyword(s):  
Electrical Stimulation ◽  
Clinical Data ◽  
Animal Studies ◽  
Receptive Fields ◽  
Lewy Body Dementia ◽  
Clinical Situation ◽  
Nucleus Basalis ◽  
Nucleus Basalis Of Meynert ◽  
Clinical Effects ◽  
Stimulation Of

AbstractDeep brain stimulation (DBS) of the nucleus basalis of Meynert (NBM) has been clinically investigated in Alzheimer’s disease (AD) and Lewy body dementia (LBD). However, the clinical effects are highly variable, which questions the suggested basic principles underlying these clinical trials. Therefore, preclinical and clinical data on the design of NBM stimulation experiments and its effects on behavioral and neurophysiological aspects are systematically reviewed here. Animal studies have shown that electrical stimulation of the NBM enhanced cognition, increased the release of acetylcholine, enhanced cerebral blood flow, released several neuroprotective factors, and facilitates plasticity of cortical and subcortical receptive fields. However, the translation of these outcomes to current clinical practice is hampered by the fact that mainly animals with an intact NBM were used, whereas most animals were stimulated unilaterally, with different stimulation paradigms for only restricted timeframes. Future animal research has to refine the NBM stimulation methods, using partially lesioned NBM nuclei, to better resemble the clinical situation in AD, and LBD. More preclinical data on the effect of stimulation of lesioned NBM should be present, before DBS of the NBM in human is explored further.

Corticogeniculate neurons, corticotectal neurons, and suspected interneurons in visual cortex of awake rabbits: receptive-field properties, axonal properties, and effects of EEG arousal

1987 ◽  
Vol 57 (4) ◽  
pp. 977-1001 ◽  
Author(s):  
H. A. Swadlow ◽  
T. G. Weyand
Keyword(s):  
Electrical Stimulation ◽  
Visual Cortex ◽  
Receptive Field ◽  
Receptive Fields ◽  
Spontaneous Firing ◽  
Visual Responses ◽  
Firing Rates ◽  
Axonal Conduction ◽  
Conduction Velocities ◽  
Stimulation Of

The intrinsic stability of the rabbit eye was exploited to enable receptive-field analysis of antidromically identified corticotectal (CT) neurons (n = 101) and corticogeniculate (CG) neurons (n = 124) in visual area I of awake rabbits. Eye position was monitored to within 1/5 degrees. We also studied the receptive-field properties of neurons synaptically activated via electrical stimulation of the dorsal lateral geniculate nucleus (LGNd). Whereas most CT neurons had either complex (59%) or motion/uniform (15%) receptive fields, we also found CT neurons with simple (9%) and concentric (4%) receptive fields. Most complex CT cells were broadly tuned to both stimulus orientation and velocity, but only 41% of these cells were directionally selective. We could elicit no visual responses from 6% of CT cells, and these cells had significantly lower conduction velocities than visually responsive CT cells. The median spontaneous firing rates for all classes of CT neurons were 4-8 spikes/s. CG neurons had primarily simple (60%) and concentric (9%) receptive fields, and none of these cells had complex receptive fields. CG simple cells were more narrowly tuned to both stimulus orientation and velocity than were complex CT cells, and most (85%) were directionally selective. Axonal conduction velocities of CG neurons (mean = 1.2 m/s) were much lower than those of CT neurons (mean = 6.4 m/s), and CG neurons that were visually unresponsive (23%) had lower axonal conduction velocities than did visually responsive CG neurons. Some visually unresponsive CG neurons (14%) responded with saccadic eye movements. The median spontaneous firing rates for all classes of CG neurons were less than 1 spike/s. All neurons synaptically activated via LGNd stimulation at latencies of less than 2.0 ms had receptive fields that were not orientation selective (89% motion/uniform, 11% concentric), whereas most cells with orientation-selective receptive fields had considerably longer synaptic latencies. Most short-latency motion/uniform neurons responded to electrical stimulation of the LGNd (and visual area II) with a high-frequency burst (500-900 Hz) of three or more spikes. Action potentials of these neurons were of short duration, thresholds of synaptic activation were low, and spontaneous firing rates were the highest seen in rabbit visual cortex. These properties are similar to those reported for interneurons in several regions in mammalian central nervous system. Nonvisual sensory stimuli that resulted in electroencephalographic arousal (hippocampal theta activity) had a profound effect on the visual responses of many visual cortical neurons.(ABSTRACT TRUNCATED AT 400 WORDS)

Responses of neurons in VPL and VPL-VL region of the cat to algesic stimulation of muscle and tendon

1983 ◽  
Vol 49 (3) ◽  
pp. 649-661 ◽  
Author(s):  
K. D. Kniffki ◽  
K. Mizumura
Keyword(s):  
Electrical Stimulation ◽  
Mechanical Stimulation ◽  
Receptive Fields ◽  
Transitional Zone ◽  
The Other ◽  
Group Iii ◽  
Group I ◽  
Nociceptive Information ◽  
Noxious Mechanical Stimulation ◽  
Stimulation Of

1. The responses evoked by electrical stimulation of cutaneous and muscle nerves, by noxious and innocuous mechanical stimulation of muscle, tendon, and cutaneous tissues, and by intra-arterial (ia) injection of algesic substances (potassium, bradykinin) into arteries supplying the gastrocnemius-soleus muscle (GS) were studied in single neurons located in the ventroposterolateral nucleus (VPL) and in the transitional zone between VPL and the ventrolateral nucleus (VL) of cats lightly anesthetized with thiopenthal. Such chemical stimulation of the muscles has been shown to activate muscular groups III and IV axons specifically (43, 44) and presumably is nociceptive in character (14, 17, 31). 2. One hundred eight neurons were tested. Eighty-three of the units responded only to various types of cutaneous stimulation of the hindlimb. The other 25 responded to algesic stimulation of muscle and/or tendon. Of these latter 25, 7 had no apparent cutaneous receptive field although 4 of them responded to electrical stimulation of the common peroneal and/or sural nerve. Thus, only three neurons responded exclusively to algesic chemical and noxious mechanical stimulation of the muscle. Of the other 18 neurons, 14 had cutaneous receptive fields restricted to the hindlimb and often responded to non-noxious repetitive light stroking and to noxious pinching with a high-frequency discharge. Four cells (two of which had cutaneous input only from low-threshold mechanoreceptors) had complex and large receptive fields extending to more than one limb. 3. Potassium was a more potent muscle receptor stimulant than bradykinin, the latter only weakly exciting 3 neurons of 24 tested with both substances. The responses to potassium were rapid (approximately 4.0 s in latency) and tended to be greater (have higher response rates) for the units that responded to cutaneous as well as muscle/tendon stimulation. 4. Most neurons that responded to noxious deep stimulation had a threshold for the GS nerve volley in the group III fiber range. The few neurons with thresholds slightly below the group III range did not respond to activation of group I or II muscle spindle afferents by intra-arterial application of succinylcholine or by stretching the muscle. 5. Neurons with responses to any of the muscle, tendon, or cutaneous nociceptive stimuli were located at the ventral and dorsal periphery of VPL and in the VPL-VL transitional zone. 6. These results strongly suggest that there exist regions within the lateral diencephalon of cats that are capable of processing nociceptive information and that these regions are located at the periphery of VPL.

Reorganization of the receptive fields of spinocervical tract neurons following denervation of a single digit in the cat

1987 ◽  
Vol 57 (3) ◽  
pp. 803-818 ◽  
Author(s):  
P. Wilson ◽  
P. J. Snow
Keyword(s):  
Dorsal Horn ◽  
Receptive Fields ◽  
Light Touch ◽  
Single Digit ◽  
Dorsal Horn Neurons ◽  
Somatotopic Organization ◽  
Low Threshold ◽  
Adult Cat ◽  
Adult Cats ◽  
Central Reorganization

The effect of acute and chronic section of the digital nerves of a single toe on the organization of low-threshold, mechanoreceptive fields of lumbosacral spinocervical tract (SCT) neurons has been studied in adult cats anesthetized with chloralose. The immediate effect of sectioning the digital nerves of a single toe is to produce a patch of dorsal horn in the medial region of the ipsilateral lumbosacral cord in which SCT neurons lack any peripheral receptive field when gentle hair movement or light touch of glabrous skin are used as stimuli. Other SCT neurons in the region may lose only part of their receptive fields. Between 30 and 70 days later most of the affected SCT neurons have established receptive fields. These are mainly on somatotopically inappropriate areas of skin medially and laterally adjacent to the denervated region. A small proportion of SCT neurons form discontinuous receptive fields. The relative somatotopic organization within the affected region remains unchanged. As there is no sign of regeneration of the sectioned nerves the new receptive fields must result from a central reorganization of excitatory inputs to SCT neurons. It is concluded that chronic peripheral nerve section affects the anatomical and physiological mechanisms underlying the formation of light touch receptive fields of dorsal horn neurons in the lumbosacral cord of the adult cat, but that the resulting reorganization of receptive fields is spatially restricted.

Splanchnic and somatic afferent convergence on cervical spinal neurons of the rat

1994 ◽  
Vol 266 (1) ◽  
pp. R268-R276 ◽  
Author(s):  
E. W. Akeyson ◽  
L. P. Schramm
Keyword(s):  
Electrical Stimulation ◽  
Cervical Spinal Cord ◽  
Receptive Fields ◽  
Splanchnic Nerve ◽  
Whole Body ◽  
Spinal Neurons ◽  
Somatic Afferents ◽  
Greater Splanchnic Nerve ◽  
Somatic Input ◽  
Stimulation Of

The rostral cervical spinal cord is increasingly being considered the source of important propriospinal regulation. To better understand the substrate for this function, we investigated the effects of stimulation of the greater splanchnic nerve (GSN) and both thoracic and cervical somatic afferents on the activity of cervical spinal neurons. Extracellular single-neuron recordings were made in the C2-C5 spinal segments of chloralose-anesthetized, paralyzed, and artificially ventilated rats. Neurons were classified according to their responses to GSN stimulation. Neurons were inhibited by this stimulation as frequently as they were excited. We then studied the characteristics of cervical and thoracic convergent somatic input to each class of neurons. Although all cervical neurons that responded to GSN stimulation responded to electrical stimulation of the iliohypogastric nerve (IHN), only the few neurons that exhibited whole body receptive fields (RF) responded to natural thoracic somatic stimuli. Responses to electrical stimulation of the GSN and IHN were similar for most neurons; most exhibited nociceptive cutaneous RFs in cervical dermatomes. These data indicate that input from cervical somatic afferents and from both thoracic visceral and thoracic somatic afferents converge on individual splanchnic-receptive cervical neurons. Although these neurons exhibited the predicted cervical somatic RFs, responses from thoracic levels did not exhibit discrete RFs, requiring instead more synchronous or more spatially convergent input.

scholarly journals Effect of electrical stimulation of receptive fields in people with lower limb amputation on variables of gait

IBRO Reports ◽  
2020 ◽  
Vol 9 ◽  
pp. 78-84
Author(s):  
Michael Pleus ◽  
Thomas Koller ◽  
Felix Tschui ◽  
Marion Grögli ◽  
Christina M. Spengler
Keyword(s):  
Electrical Stimulation ◽  
Lower Limb ◽  
Receptive Fields ◽  
Lower Limb Amputation ◽  
Limb Amputation ◽  
Stimulation Of
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