Effects Of Deafferentation Research Articles

The effect of deafferentation on the postnatal development of Clarke's nucleus in the kitten — a Golgi study

Kittens 3–14 days of age were deafferented unilaterally from L 3 to S 3. The contralateral side served as the control. Following a 16 day survival period, the kittens were sacrificed and spinal segments from T 10 to L 3 were removed and processed according to the Ha modification of the Golgi-Cox method. The results of this study indicate that deafferentation of Clarke's nucleus in the 3 and 5 day kitten produces neuronal hypoplasia and a bizarre dendritic orientation characterized by the projection of dendritic branches toward the midline. Deafferentation after the first week produces some hypoplasia, but no dendritic alterations. It is proposed that the observed dendritic alterations are the result of sensory deprivation at a critical stage in the postnatal development of this nucleus. Furthermore, it is suggested that the observed reorientation of dendrites may represent the projection of dendritic branches toward viable afferent sources.

The effect of deafferentation of the pseudobranch on the respiratory response to hypoxia and hyperoxia in the trout ( Salmo gairdneri)

The effect of bilateral deafferentation of the pseudobranch on the ventilatory responses of rainbow trout to hypoxia and hyperoxia has been studied. Intact trout responded to hypoxia by an increase, and to hyperoxia by a decrease in ventilation volume. The changes were achieved by alterations in the volume of water pumped per breathing cycle rather than in breathing rate. Pao, and Vo, decreased during hypoxia but increased during hyperoxia. Arterial blood pH rose during hypoxia and fell during hyperoxia. Deafferentation of the pseudobranch had no significant effect on either the magnitude or rate of response to hypoxia or hyperoxia. It is concluded that chemoreceptors in the pseudobranch, innervated by the glossopharyngeal nerve, play little or no part in the regulation of ventilation in fish during hypoxia or hyperoxia.

Deafferentation effects in lateral cuneate nucleus of the cat: Correlation of structural alterations with firing pattern changes

A correlated anatomical and physiological investigation of the effects of unilateral cervicothoracic dorsal rhizotomies upon lateral cuneate nucleus of the cat (LCN) is reported. Pairs of adult cats with identical survival times were selected to correlate structural and functional changes. Two phases are described in the development of alterations of neuronal firing patterns. In the first phase, a relative silence within LCN was associated with depletion of round synaptic vesicles in the presynaptic profiles (LR boutons) of primary dorsal root afferents. The second phase was characterized by a development of spontaneous electrical hyperactivity which corresponded anatomically to the presence of denuded postsynaptic specializations, transient increase of adjacent extracellular space and an apparent decrease in the number of dendritic spines. There was a persistence of an unaltered population of small presynaptic boutons with flattened vesicles (SF boutons). The LCN neuronal membrane is viewed as having an intrinsic tendency for repetitive firing which is enhanced by the functional effects of denuded postsynaptic specialization. A marked similarity was found between some of the spontaneous firing patterns of normal animals (doublets) and the high frequency bursting firing pattern in deafferented preparation. Three models for repetitive spike production are considered in our analysis: oscillator-produced spikes; EPSP-produced spikes; and spike-evoked spikes. The spike-evoked spikes model is considered to be the origin of normal doublet activity and a candidate for the deafferented burst activity. Abnormal hyperactivity after deafferentation may be a function of changes in the membrane characteristics occurring at or near the denuded postsynaptic specializations.

Effects of deafferentation and vibration on precision grip in monkey and man

Effects of deafferentation and vibration on precision grip in monkey and man

Changes in the catecholamine content of the rat hypothalamus following deafferentation.

A study has been made of the effects of deafferentation on the catecholamine content of the basal hypothalamus in the rat. Concentrations of norepinephrine and dopamine in the hypothalamus were determined by the trihydroxyindole fluorescence technique following anterior, posterior or complete deafferentation of the medial basal hypothalamus. Complete deafferentation caused a highly significant 38% decrease in norepinephrine within a large basal hypothalamic fragment containing the deafferented island. Results with partial deafferentations showed that this decrease could be attributed to the severing of the lateral input and possibly also the anterior connections entering the island. When the catecholamine content of the completely deafferented island itself was measured, norepinephrine was found to be totally depleted while dopamine concentration was not changed significantly. These data suggested that both the cell bodies and the axons of dopamine-containing neurons lay within the medial basal hypothalam...

Effect of deafferentation of the anterior lobe of the cat cerebellum on background activity of Purkinje cells

Background activity of Purkinje cells is compared in the intact cat cerebellar cortex and after deafferentation. Deafferentation causes a slight increase in frequency and regularity of discharge of the Purkinje cells, mainly through a decrease in the percentage of long interspike intervals. Consequently, incoming afferent impulses exert a mainly inhibitory effect on spontaneous activity of Purkinje cells. A study of interaction between neighboring Purkinje cells after deafferentation of the cerebellar cortex showed that they mutually inhibit each other. This effect is evidently mediated by recurrent axon collaterals of the Purkinje cells in the isolated cerebellar cortex; in contrast, with the intact cortex, no “complex” spikes of the Purkinje cells were observed.

The effect of Trigeminal Nerve Block on the Articulatory Emg Activity of Facial Muscles

The effect of blocking trigeminal afferent fibres was studied with reference to the EMG activity of facial muscles during speech production. Normal-speaking subjects were investigated without and with mandibular anaesthesia, and patients with trigeminal neuralgia before and after blockade of the Gasserian ganglion. No audible difference was detected between the non-anaesthetized and the uni-or bilaterally anaesthetized. The most consistent and salient finding was a general increase in the amount of prespeech and background activity as well as, in particular, the amount of articulatory activity. This increase often appeared symmetrically on both sides even with unilateral anaesthesia and was localized to the muscles that are best adapted for the production of the speech sounds in question, while the cocontractive activity of the antagonistic muscles decreased. The increase was often associated with an earlier onset of articulatory activity. The context dependence of the EMG activity was obviously impaired for the production of vowels but not of consonants. These EMG observations are discussed in relation to previous reports by other authors on the effects of de-afferentation of the limb and intercostal musculature. It is concluded that the EMG changes observed after blocking of afferent activity in the trigeminal nerve cannot be explained by a disturbed peripheral closed-loop feedback, similar to the muscle spindle-gamma efferent system, which therefore does not seem to be crucial for adult speech production. However, the findings could be accounted for by a disturbed positional sense. To compensate for this disturbance, the control of articulatory activity, which is not normally conscious, may be referred to a higher level of the central nervous system. Such a more conscious motor control might explain the overshooting muscle activation and the lack of context dependence of the EMG activity.

Effect of sciatic neurectomy on myelinogenesis in the rat spinal cord

In an attempt to determine the effect of deafferentation upon central nervous system myelinogenesis, a right sciatic neurectomy was performed on newborn rats. The dorsal funiculus of the thoracic spinal cord was studied on subsequent days, and the results indicated definite deficiencies on the deafferented side which included fewer large axons and thinner myelin sheaths. Phase microscopic data are presented along with measurements of axon diameter and myelin sheath thickness. It is concluded from these experiments that physiologic activity in the nerve fiber is a significant factor affecting myelinogenesis, which exerts its effect through some mechanism other than axonal size alone.

Effect of deafferentation of an arm upon the tremor of the opposite arm.

Effect of deafferentation of an arm upon the tremor of the opposite arm.

Some effects of deafferentation on neurons of the cat spinal cord.

THE firing characteristics of individual neurons of the mammalian nervous system have been studied in varying structures with a wide range of stimuli, anesthetics, and surgical procedures, while attention has not been focused upon comparing spontaneous activity in normal and abnormal states. Previous studies of activity in the cortical focus by Ward et al 1-4 have elucidated two attributes of epileptic neurons: autonomous high-frequency bursts and loss of synaptic drive which has been attributed to the absence of dendritic spines. 5 On the basis of these investigations, it has been postulated that the epileptic cell is in a state of partial functional deafferentation and that the abnormal firing pattern is a consequence of this deafferentation. Studies utilizing cortical neurons cannot divorce afferent from efferent activity because of the complex geometry of the cortical feltwork but the anatomy of the spinal cord permits deafferentation without manipulation of efferent systems.

Properties of frog sympathetic neurons in normal ganglia and after axon section.

Properties of frog sympathetic neurons in normal ganglia and after axon section.C C Hunt, and W K RikerC C Hunt, and W K RikerPublished Online:01 Nov 1966https://doi.org/10.1152/jn.1966.29.6.1096MoreSectionsPDF (3 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited BySynaptic and Somatic Effects of Axotomy in the Intact, Innervated Rat Sympathetic NeuronOscar Sacchi, Maria Lisa Rossi, Rita Canella, and Riccardo Fesce1 May 2006 | Journal of Neurophysiology, Vol. 95, No. 5Amphibian sympathetic ganglia: An owner's and operator's manualProgress in Neurobiology, Vol. 43, No. 4-5Structural and functional modifications of ganglionic synapses after axotomy in the frogJournal of the Autonomic Nervous System, Vol. 33, No. 2Explant cultures of adult amphibian sympathetic ganglia: Electrophysiological and pharmacological investigation of neurotransmitter and nucleotide actionBrain Research, Vol. 223, No. 1Selective synaptic changes following spinal motoneuron axotomyBrain Research, Vol. 189, No. 1α-Bungarotoxin binding sites in the rat superior cervical ganglion are influenced by postganglionic axotomyNeuroscience, Vol. 5, No. 3Axotomy in rat sympathetic ganglia: reciprocal effects on muscarinic receptor binding and 6-phosphogluconate dehydrogenase activityBrain Research, Vol. 161, No. 3α-Bungarotoxin-acetylcholine receptors in the chick ciliary ganglion: Effects of deafferentation and axotomyBrain Research, Vol. 153, No. 1Avian sympathetic cardiac fibers and their cells of origin: anatomical and electrophysiological characteristicsBrain Research, Vol. 131, No. 1Intracellular postsynaptic potentials of cat lateral geniculate cells and the effects of degeneration of the optic terminalsBrain Research, Vol. 98, No. 3Metabolic alterations in the axotomized superior cervical ganglion of the rat. I. Energy metabolismBrain Research, Vol. 65, No. 1A simple method for the preparation of and recording from thin slices of living tissueBrain Research, Vol. 30, No. 2 More from this issue > Volume 29Issue 6November 1966Pages 1096-114 https://doi.org/10.1152/jn.1966.29.6.1096PubMed5971664History Published online 1 November 1966 Published in print 1 November 1966 Metrics

Effect of deafferentation on the morphological and histochemical characteristics of the lung cells of the cat

Effect of deafferentation on the morphological and histochemical characteristics of the lung cells of the cat

Extent of recovery from the effects of visual deprivation in kittens.

Seven kittens were used, and the various procedures of deprivation and subsequent studies are summarized in Table 1. In six animals the Iids of one eye were closed for the first 3 months of life. In the recovery period two of these kittens had the deprived eye opened. The other four had the deprived eye opened and the other (previously open) eye was closed. The seventh animal had both eyes closed for 3 months; the right eye was then opened. Recovery periods

Some effects of de-afferentation on the developing amphibian nervous system

ABSTRACT An adult anuran can still walk or swim if the nerves supplying one or even two limbs are de-afferentated (Gray, 1950). However, in a developing amphibian, a limb at motile stages becomes paralysed when deprived of its sensory input. A sequence of degenerative changes then follow in the cord and in peripheral nerves.

RECEPTIVE FIELDS AND FUNCTIONAL ARCHITECTURE IN TWO NONSTRIATE VISUAL AREAS (18 AND 19) OF THE CAT.

RECEPTIVE FIELDS AND FUNCTIONAL ARCHITECTURE IN TWO NONSTRIATE VISUAL AREAS (18 AND 19) OF THE CAT.

Effect of deafferentation upon acquisition of a conditioned flexion response in the cat

The ability of naive cats to acquire a conditioned flexion response in a hind limb deprived of sensory inflow was studied. In some cats dorsal-root section was extended from T13 through S3, while in others a more restricted deafferentation was carried out. A bipolar stimulating electrode was chronically implanted on dorsal root L6. The cats were subjected to a classical conditioning procedure in which tone (CS) was paired with shock (US) delivered through the dorsal-root electrode. All animals were given at least 750 training trials over 19 training sessions. The US produced a consistent flexion of the deafferented leg, and EMG recordings showed that the deafferented flexor muscles contracted to the US. None of four cats with complete deafferentation of the muscles participating in the unconditioned responses acquired a conditioned flexion response in the deafferented limb. Four other cats with partial deafferentation of the hind limb all developed conditioned flexion responses in that limb. We conclude that, in the cat, a classically conditioned flexion response cannot be acquired in the hind limb without local sensory inflow.

RECEPTIVE FIELDS OF CELLS IN STRIATE CORTEX OF VERY YOUNG, VISUALLY INEXPERIENCED KITTENS.

RECEPTIVE FIELDS OF CELLS IN STRIATE CORTEX OF VERY YOUNG, VISUALLY INEXPERIENCED KITTENS.

EFFECTS OF VISUAL DEPRIVATION ON MORPHOLOGY AND PHYSIOLOGY OF CELLS IN THE CATS LATERAL GENICULATE BODY.

EFFECTS OF VISUAL DEPRIVATION ON MORPHOLOGY AND PHYSIOLOGY OF CELLS IN THE CATS LATERAL GENICULATE BODY.

Effect of deafferentation on a conditioned avoidance response.

To determine whether peripheral afferent pathways could be bypassed in the performance of purposive movement, a group of monkeys was trained to avoid shock by flexing a forelimb in response to an auditory stimulus. The dorsal roots of the responding limb were then sectioned. Postoperatively it was found that the affected limb could be reconditioned.

Radiation as an experimental tool in mammalian developmental neurology.

ArticlesRadiation as an Experimental Tool in Mammalian Developmental NeurologySamuel P. HicksSamuel P. HicksPublished Online:01 Jul 1958https://doi.org/10.1152/physrev.1958.38.3.337MoreSectionsPDF (4 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited BySerial injections of MK 801 (Dizocilpine) in neonatal rats reduce behavioral deficits associated with X-ray-induced hippocampal granule cell hypoplasiaPharmacology Biochemistry and Behavior, Vol. 43, No. 3Early neural grafts transiently reduce the behavioral effects of radiation-induced fascia dentata granule cell hypoplasiaBrain Research, Vol. 550, No. 1Neural grafts attenuate behavioral deficits produced by early radiation-induced hypoplasia of fascia dentata granule cellsBrain Research, Vol. 509, No. 2Vertical compartmentation and cellular transformations in the germinal matrices of the embryonic rat cerebral cortexExperimental Neurology, Vol. 107, No. 1Progressive behavioral changes during the maturation of rats with early radiation-induced hypoplasia of fascia dentata granule cellsNeurotoxicology and Teratology, Vol. 11, No. 4Morphological and behavioral markers of environmentally induced retardation of brain development: an animal model.Environmental Health Perspectives, Vol. 74Early X-irradiation of rats. 1. Methodological description and morphological observations on the olfactory bulbJournal of Neuroscience Methods, Vol. 18, No. 3Selective ablation of neurons by methylazoxymethanol during pre- and postnatal brain developmentExperimental Neurology, Vol. 94, No. 1Behavioral Toxicity of Nitrous Oxide in Rats Following Prenatal Exposure30 June 2016 | Toxicology and Industrial Health, Vol. 2, No. 3The protective effects of vitamin E on microcephaly in rats X-irradiated in utero: DNA, lipid peroxide and confronting cisternaeDevelopmental Brain Research, Vol. 27, No. 1Dose-dependent occurrence of the aberrant longitudinal bundle in the brains of mice born acallosal after prenatal gamma irradiationDevelopmental Brain Research, Vol. 25, No. 1Central canal area in the early postnatal rat: Normal development and radiation-induced changesDevelopmental Brain Research, Vol. 14, No. 2Radiosensitivity of the granule cell line and other cell types of the immature rat cerebellar cortexExperimental Neurology, Vol. 77, No. 1Development of the motor system: Effects of radiation on developing corticospinal neurons and locomotor functionExperimental Neurology, Vol. 70, No. 1Normal development and post-traumatic plasticity of corticospinal neurons in ratsExperimental Neurology, Vol. 60, No. 3The effect of deafferentation on the development of brain and spinal nucleiProgress in Neurobiology, Vol. 8The effects of reduced climbing and parallel fibre input on Purkinje cell dendritic growthBrain Research, Vol. 109, No. 1The morphogenesis of hydranencephalyJournal of the Neurological Sciences, Vol. 12, No. 2Differential radiosensitivity of stationary and migratory primitive cells in the brains of infant ratsExperimental Neurology, Vol. 22, No. 1Gross morphological consequences of irradiation of the cerebellum in infant rats with repeated doses of low-level X-rayExperimental Neurology, Vol. 21, No. 1III. Histopathologic findingsBrain Research, Vol. 7, No. 1Convulsive responses in prenatally irradiated ratsExperimental Neurology, Vol. 16, No. 1Electrocortical activity in the rat x-irradiated during early developmentElectroencephalography and Clinical Neurophysiology, Vol. 15, No. 1In Defense of “Prenatal Anoxia and Irradiation: Maternal-Fetal Relations”1 September 2016 | Psychological Reports, Vol. 11, No. 1Cell proliferation and migration in the primitive ependymal zone; An autoradiographic study of histogenesis in the nervous systemExperimental Neurology, Vol. 1, No. 4 More from this issue > Volume 38Issue 3July 1958Pages 337-356 https://doi.org/10.1152/physrev.1958.38.3.337PubMed13567039History Published online 1 July 1958 Published in print 1 July 1958 Metrics