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.

Convergence of heterotopic nociceptive information onto neurons of caudal medullary reticular formation in monkey (Macaca fascicularis)

1990 ◽  
Vol 63 (5) ◽  
pp. 1118-1127 ◽  
Author(s):  
L. Villanueva ◽  
K. D. Cliffer ◽  
L. S. Sorkin ◽  
D. Le Bars ◽  
W. D. Willis
Keyword(s):  
Electrical Stimulation ◽  
Reticular Formation ◽  
Mechanical Stimulation ◽  
Background Activity ◽  
The Body ◽  
Thermal Stimulation ◽  
Medullary Reticular Formation ◽  
Nociceptive Information ◽  
Noxious Mechanical Stimulation ◽  
Stimulation Of

1. Recordings were made in anesthetized monkeys from neurons in the medullary reticular formation (MRF) caudal to the obex. Responses of 19 MRF neurons to mechanical, thermal, and/or electrical stimulation were examined. MRF neurons exhibited convergence of nociceptive cutaneous inputs from widespread areas of the body and face. 2. MRF neurons exhibited low levels of background activity. Background activity increased after periods of intense cutaneous mechanical or thermal stimulation. Nearly all MRF neurons tested failed to respond to heterosensory stimuli (flashes, whistle sounds), and none responded to joint movements. 3. MRF neurons were excited by and encoded the intensity of noxious mechanical stimulation. Responses to stimuli on contralateral limbs were greater than those to stimuli on ipsilateral limbs. Responses were greater to stimuli on the forelimbs than to stimuli on the hindlimbs. 4. MRF neurons responded to noxious thermal stimulation (51 degrees C) of widespread areas of the body. Mean responses from stimulation at different locations were generally parallel to those for noxious mechanical stimulation. Responses increased with intensity of noxious thermal stimulation (45-50 degrees C). 5. MRF neurons responded with one or two peaks of activation to percutaneous electrical stimulation applied to the limbs, the face, or the tail. The differences in latency of responses to stimulating two locations along the tail suggested that activity was elicited by activation of peripheral fibers with a mean conduction velocity in the A delta range. Stimulation of the contralateral hindlimb elicited greater responses, with lower thresholds and shorter latencies, than did stimulation of the ipsilateral hindlimb. 6. Electrophysiological properties of monkey MRF neurons resembled those of neurons in the medullary subnucleus reticularis dorsalis (SRD) in the rat. Neurons in the caudal medullary reticular formation could play a role in processing nociceptive information. Convergence of nociceptive cutaneous input from widespread areas of the body suggests that MRF neurons may contribute to autonomic, affective, attentional, and/or sensory-motor processes related to pain.

Mechanical sensitivity of group III and IV afferents from posterior articular nerve in normal and inflamed cat knee

1986 ◽  
Vol 55 (4) ◽  
pp. 635-643 ◽  
Author(s):  
P. Grigg ◽  
H. G. Schaible ◽  
R. F. Schmidt
Keyword(s):  
Sciatic Nerve ◽  
Knee Joint ◽  
Conduction Velocity ◽  
Mechanical Stimulation ◽  
Dorsal Root ◽  
Receptive Fields ◽  
Group Iv ◽  
Mechanical Sensitivity ◽  
Group Iii ◽  
Stimulation Of

Recordings were performed from sciatic nerve or dorsal root filaments in 28 cats to study single group III (conduction velocity 2.5-20 m/s) and group IV (conduction velocity less than 2.5 m/s) units supplying the knee joint via the posterior articular nerve (PAN). In seven of these cats the knee joint had been inflamed artificially. Recordings from sciatic nerve filaments revealed responses to local mechanical stimulation of the joint in only 3 of 41 group IV units and in 12 of 18 group III units from the normal joint. In the inflamed joint 14 of 36 group IV units and 24 of 36 group III units were excited with local mechanical stimulation. In recordings from dorsal root filaments (normal joint) 4 of 11 group IV units and 7 of 13 group III units were activated by stimulating the joint locally. In the normal joint four group IV units (recorded from dorsal root filaments) responded only to rotations against the resistance of the tissue, whereas the majority of the fibers did not respond even to forceful movements. Group III units with local mechanosensitivity in the normal joint reacted strongly or weakly to movements in the working range of the joint or only to movements against resistance of the tissue. In the inflamed joint, group IV fibers (recorded in sciatic nerve filaments) with detectable receptive fields responded strongly to gentle movements or only to movements against resistance of tissue. Some did not react to movements. Group III units reacted strongly or weakly to gentle movements or only to movements against resistance of the tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Processing of Nociceptive Mechanical and Thermal Information in Central Amygdala Neurons With Knee-Joint Input

2002 ◽  
Vol 87 (1) ◽  
pp. 103-112 ◽  
Author(s):  
Volker Neugebauer ◽  
Weidong Li
Keyword(s):  
Knee Joint ◽  
Mechanical Stimulation ◽  
Receptive Fields ◽  
Central Nucleus ◽  
Response Functions ◽  
Central Amygdala ◽  
Deep Tissue ◽  
Stimulus Response ◽  
Noxious Mechanical Stimulation ◽  
Stimulation Of

Pain has a strong emotional dimension, and the amygdala plays a key role in emotionality. The processing of nociceptive mechanical and thermal information was studied in individual neurons of the central nucleus of the amygdala, the target of the spino-parabrachio-amygdaloid pain pathway and a major output nucleus of the amygdala. This study is the first to characterize nociceptive amygdala neurons with input from deep tissue, particularly the knee joint. In 46 anesthetized rats, extracellular single-unit recordings were made from 119 central amygdala neurons that were activated orthodromically by electrical stimulation in the lateral pontine parabrachial area and were tested for receptive fields in the knee joints. Responses to brief mechanical stimulation of joints, muscles, and skin and to cutaneous thermal stimuli were recorded. Receptive-field sizes and thresholds were mapped and stimulus-response functions constructed. Neurons in the central nucleus of the amygdala with excitatory input from the knee joint ( n = 62) typically had large symmetrical receptive fields in both hindlimbs or in all four extremities and responded exclusively or preferentially to noxious mechanical stimulation of deep tissue ( n = 58). Noxious mechanical stimulation of the skin excited 30 of these neurons; noxious heat activated 21 neurons. Stimulus-response data were best fitted by a sigmoid nonlinear regression model rather than by a monotonically increasing linear function. Another 15 neurons were inhibited by noxious mechanical stimulation of the knee joint and other deep tissue. Fifteen neurons had no receptive field in the knee but responded to noxious stimulation of other body areas; 27 nonresponsive neurons were not activated by natural somesthetic stimulation. Our data suggest that excitation is the predominant effect of brief painful stimulation of somatic tissue on the population of central amygdala neurons with knee joint input. Their large symmetrical receptive fields and sigmoid rather than monotonically increasing linear stimulus-response functions suggest a role of nociceptive central amygdala neurons in other than sensory-discriminative aspects of pain.

Physiological characterization of spinohypothalamic tract neurons in the lumbar enlargement of rats

1991 ◽  
Vol 66 (1) ◽  
pp. 261-284 ◽  
Author(s):  
R. Burstein ◽  
R. J. Dado ◽  
K. D. Cliffer ◽  
G. J. Giesler
Keyword(s):  
Dorsal Horn ◽  
Gray Matter ◽  
Mechanical Stimulation ◽  
Dynamic Range ◽  
Receptive Fields ◽  
Optic Tract ◽  
Antidromic Activation ◽  
Noxious Stimuli ◽  
Noxious Mechanical Stimulation ◽  
Stimulation Of

1. Ninety-six neurons in the lumbar enlargement of urethananesthetized rats were antidromically activated from the contralateral hypothalamus. The antidromic stimulating electrode was moved systematically within the hypothalamus until antidromic activation could be produced with currents of less than or equal to 50 microA (18.6 +/- 10.8 microA; mean +/- SD). The points at which antidromic activation thresholds were lowest were found in several regions of the hypothalamus but were concentrated in the optic tract and the supraoptic decussation. 2. The recording locations of 79 spinohypothalamic tract (SHT) neurons were marked and recovered. Twenty-nine were located in the superficial dorsal horn (SDH), 42 in the deep dorsal horn (DDH), 4 in the intermediate zone, and 2 in the gray matter surrounding the central canal. Two additional marks were located in the dorsal lateral funiculus (DLF). 3. The responses of 46 SHT neurons were examined during innocuous and noxious mechanical stimulation of their receptive fields. Forty-eight percent of recorded SHT neurons responded to both innocuous and noxious stimuli (wide dynamic range, WDR) and 39% responded only to noxious stimuli (high threshold, HT). Therefore 87% of SHT neurons responded preferentially or exclusively to noxious mechanical stimulation. Nine percent of SHT neurons responded exclusively to innocuous manipulation of joints and muscles. Four percent of SHT neurons responded only to innocuous tactile stimul (low threshold, LT). WDR, HT, and LT neurons were recorded widely throughout the dorsal horn; no relationship was found between the locations of recording sites in the dorsal horn and the response types of the neurons. SHT neurons that responded to stimulation of muscle, tendon, or joint were recorded deep in the gray matter. 4. The effects of heating the receptive fields were determined for 25 SHT neurons. Fourteen (56%) responded to thermal stimuli. Six (43%) of the responsive neurons responded at low frequencies to innocuous warming (38-41 degrees C) but more vigorously to noxious (greater than or equal to 45 degrees C) heating. The other eight responded only to noxious heat. Eighteen percent (3/17) of tested SHT neurons were activated by noxious cooling of their receptive fields. 5. Cutaneous receptive fields of most recorded SHT neurons were small, typically involving areas as small as two or three toes on the ipsilateral hindlimb; the largest receptive fields covered the entire paw. These findings indicate that relatively precise information about the location of innocuous and noxious stimuli is conveyed directly to the hypothalamus by SHT neurons.(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.

Seasonal variations in wool growth and heat tolerance of sheep. I. Wool growth

1960 ◽  
Vol 11 (1) ◽  
pp. 75 ◽  
Author(s):  
M Wodzicka
Keyword(s):  
Body Weight ◽  
Day Treatment ◽  
The Other ◽  
Seasonal Rhythm ◽  
Group Iii ◽  
Wool Growth ◽  
Group I ◽  
The Mean ◽  
Group Ii ◽  
The Difference

The monthly wool growth of three groups of rams was studied at Beltsville, Maryland. Group I received natural daylight (at 38° 53' N.) and was shorn monthly. Group II had a 7:17 hours of daylight to hours of darkness rhythm and was shorn every 6 months, once in winter and once in summer. Group III received natural daylight and was likewise shorn every 6 months. The rams of all groups produced more wool in summer than in winter. This difference was significant (P<0.001). The mean body weight and food intake were both greater in the winter months, which indicated that the seasonal rhythm of wool growth was not a consequence of poorer feeding in winter. The rams which were shorn monthly (group I) grew considerably more wool than the other two groups, but the difference was not statistically significant. The short-day treatment of group II did not increase the annual wool production nor decrease the seasonal rhythm of wool growth. The balance of evidence from this and other experiments indicates that temperature rather than light controls the seasonal rhythm of wool growth.

Rapid correction of severe hyponatremia in the rat: histopathological changes in the brain

1985 ◽  
Vol 248 (5) ◽  
pp. F711-F719 ◽  
Author(s):  
J. C. Ayus ◽  
R. K. Krothapalli ◽  
D. L. Armstrong
Keyword(s):  
Serum Sodium ◽  
Brain Lesions ◽  
The Other ◽  
Histopathological Changes ◽  
Water Restriction ◽  
Severe Hyponatremia ◽  
Group Iii ◽  
Group I ◽  
The Brain ◽  
Rapid Correction

The purpose of the present studies was to examine the effects of rapid correction of severe hyponatremia (serum sodium less than 120 meq/liter) either to mildly hyponatremic levels (serum sodium = 130 meq/liter) or to normonatremic levels (serum sodium = 150 meq/liter) on the brain histology of rats. In group I, 13% of the rats revealed brain lesions following correction to mildly hyponatremic levels by the administration of 855 mM NaCl. All the rats (100%) in group II had brain lesions following correction to normonatremic levels by 24 h of water restriction. Similarly, all the rats in group III showed brain lesions following correction to normonatremic levels by the administration of 855 mM NaCl. Severe hyponatremia by itself did not cause any brain lesions in another group. We conclude that rapid correction of severe hyponatremia to mildly hyponatremic levels by the administration of 855 mM NaCl does not cause significant brain lesions. On the other hand, rapid correction to normonatremic levels either by water restriction or by the administration of 855 mM NaCl results in significant brain lesions.

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