Excitation of oxytocin cells in the hypothalamic supraoptic nucleus by electrical stimulation of the dorsal penile nerve and tactile stimulation of the penis in the rat

1999 ◽  
Vol 48 (3) ◽  
pp. 309-313 ◽  
Author(s):  
Kazumasa Honda ◽  
Masahioro Yanagimoto ◽  
Hideo Negoro ◽  
Kazumi Narita ◽  
Takuya Murata ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Supraoptic Nucleus ◽  
Tactile Stimulation ◽  
Dorsal Penile Nerve ◽  
Hypothalamic Supraoptic Nucleus ◽  
Stimulation Of

Corticofugal Modulation of the Tactile Response Coherence of Projecting Neurons in the Gracilis Nucleus

2007 ◽  
Vol 98 (5) ◽  
pp. 2537-2549 ◽  
Author(s):  
Nazareth P. Castellanos ◽  
Eduardo Malmierca ◽  
Angel Nuñez ◽  
Valeri A. Makarov
Keyword(s):  
Electrical Stimulation ◽  
Tactile Stimulation ◽  
Spectral Power ◽  
Temporal Structure ◽  
Neural Response ◽  
Spike Timing ◽  
Sensory Stimulus ◽  
Functional Coupling ◽  
Tactile Response ◽  
Stimulation Of

Precise and reproducible spike timing is one of the alternatives of the sensory stimulus encoding. We test coherence (repeatability) of the response patterns elicited in projecting gracile neurons by tactile stimulation and its modulation provoked by electrical stimulation of the corticofugal feedback from the somatosensory (SI) cortex. To gain the temporal structure we adopt the wavelet-based approach for quantification of the functional stimulus–neural response coupling. We show that the spontaneous firing patterns (when they exist) are essentially random. Tactile stimulation of the neuron receptive field strongly increases the spectral power in the stimulus and 5- to 15-Hz frequency bands. However, the functional coupling (coherence) between the sensory stimulus and the neural response exhibits ultraslow oscillation (0.07 Hz). During this oscillation the stimulus coherence can temporarily fall below the statistically significant level, i.e., the functional stimulus–response coupling may be temporarily lost for a single neuron. We further demonstrate that electrical stimulation of the SI cortex increases the stimulus coherence for about 60% of cells. We find no significant correlation between the increment of the firing rate and the stimulus coherence, but we show that there is a positive correlation with the amplitude of the peristimulus time histogram. The latter argues that the observed facilitation of the neural response by the corticofugal pathway, at least in part, may be mediated through an appropriate ordering of the stimulus-evoked firing pattern, and the coherence enhancement is more relevant in gracilis nucleus than an increase of the number of spikes elicited by the tactile stimulus.

Functional magnetic resonance imaging of somatosensory cortex activity produced by electrical stimulation of the median nerve or tactile stimulation of the index finger

2000 ◽  
Vol 93 (5) ◽  
pp. 774-783 ◽  
Author(s):  
Maxwell Boakye ◽  
Sean C. Huckins ◽  
Nikolaus M. Szeverenyi ◽  
Bobby I. Taskey ◽  
Charles J. Hodge
Keyword(s):  
Electrical Stimulation ◽  
Median Nerve ◽  
Somatosensory Cortex ◽  
Tactile Stimulation ◽  
Index Finger ◽  
Functional Magnetic Resonance ◽  
Content Type ◽  
The Right ◽  
Fine Print ◽  
Stimulation Of

Object. Functional magnetic resonance (fMR) imaging was used to determine patterns of cerebral blood flow changes in the somatosensory cortex that result from median nerve stimulation (MNS).Methods. Ten healthy volunteers underwent stimulation of the right median nerve at frequencies of 5.1 Hz (five volunteers) and 50 Hz (five volunteers). The left median nerve was stimulated at frequencies of 5.1 Hz (two volunteers) and 50 Hz (five volunteers). Tactile stimulation (with a soft brush) of the right index finger was also applied (three volunteers). Functional MR imaging data were transformed into Talairach space coordinates and averaged by group. Results showed significant activation (p < 0.001) in the following regions: primary sensorimotor cortex (SMI), secondary somatosensory cortex (SII), parietal operculum, insula, frontal cortex, supplementary motor area, and posterior parietal cortices (Brodmann's Areas 7 and 40). Further analysis revealed no statistically significant difference (p > 0.05) between volumes of cortical activation in the SMI or SII resulting from electrical stimuli at 5.1 Hz and 50 Hz. There existed no significant differences (p > 0.05) in cortical activity in either the SMI or SII resulting from either left- or right-sided MNS. With the exception of the frontal cortex, areas of cortical activity in response to tactile stimulation were anatomically identical to those regions activated by electrical stimulation. In the SMI and SII, activation resulting from tactile stimulation was not significantly different (p > 0.05) from that resulting from electrical stimulation.Conclusions. Electrical stimulation of the median nerve is a reproducible and effective means of activating multiple somatosensory cortical areas, and fMR imaging can be used to investigate the complex network that exists between these areas.

Functional identification of central pressor pathways originating in the subfornical organ

1991 ◽  
Vol 69 (7) ◽  
pp. 1035-1045 ◽  
Author(s):  
John Ciriello ◽  
Michael B. Gutman
Keyword(s):  
Spinal Cord ◽  
Electrical Stimulation ◽  
Paraventricular Nucleus ◽  
Supraoptic Nucleus ◽  
Subfornical Organ ◽  
Preoptic Nucleus ◽  
Thoracic Spinal Cord ◽  
Median Preoptic Nucleus ◽  
Pressor Responses ◽  
Stimulation Of

The functional projections from pressor sites in the subfornical organ (SFO) were identified using the 2-deoxyglucose (2-DG) autoradiographic method in urethane-anesthetized, sinoaortic-denervated rats. Autoradiographs of brain and spinal cord sections taken from rats whose SFO was continuously stimulated electrically for 45 min with stereotaxically placed monopolar electrodes (150 μA, 1.5-ms pulse duration, 15 Hz) following injection of tritiated 2-DG were compared with control rats that received intravenous infusions of pressor doses of phenylephrine to mimic the increase in arterial pressure observed during SFO stimulation. Comparisons were also made to autoradiographs from rats in which the ventral fornical commissure (CFV), just dorsal to the SFO, was electrically stimulated. The pressor responses during either electrical stimulation of the SFO or intravenous infusion of phenylephrine were similar in magnitude. On the other hand, stimulation of the CFV did not elicit a significant pressor response. Electrical stimulation of the SFO increased 2-DG uptake, in comparison to the phenylephrine-infused rats, in the nucleus triangularis, septofimbrial nucleus, lateral septal nucleus, nucleus accumbens, bed nucleus of the stria terminalis, dorsal and ventral nucleus medianus (median preoptic nucleus), paraventricular nucleus of the thalamus, hippocampus, supraoptic nucleus, suprachiasmatic nucleus, paraventricular nucleus of the hypothalamus, and the intermediolateral nucleus of and central autonomic area of the thoracic spinal cord. In contrast, in rats whose CFV was stimulated, these nuclei did not demonstrate changes in 2-DG uptake compared with control animals that received pressor doses of phenylephrine. These data have demonstrated some of the components of the neural circuitry likely involved in mediating the pressor responses to stimulation of the SFO and the corrective responses to activation of the SFO by disturbances to circulatory and fluid balance homeostasis.Key words: cardiovascular reflex pathways, drinking, median preoptic nucleus, osmoreceptors, paraventricular nucleus of the hypothalamus, supraoptic nucleus.

Hypothalamic pathways for independent release of vasopressin and oxytocin

1967 ◽  
Vol 166 (1005) ◽  
pp. 422-442 ◽  
Keyword(s):  
Electrical Stimulation ◽  
Paraventricular Nucleus ◽  
Supraoptic Nucleus ◽  
Venous Blood ◽  
Simple Method ◽  
Blood Samples ◽  
Stimulation Of

By means of a simple method for extraction of blood samples, reliable recoveries of vasopressin and oxytocin were obtained. This method was used in anaesthetized cats for estimation of these hormones, released into external jugular venous blood, after localized electrical stimulation in the hypothalamus. Stimulation of the supraoptic nucleus or supraoptico-hypophysial tract released large amounts of vasopressin without oxytocin. Stimulation of the paraventricular nucleus or tractus paraventricular is cinereus (Greving) released moderate amounts of vasopressin alone. Stimulation at points in the tuberal region of the hypothalamus released oxytocin with or without vasopressin. These could lie on the caudal tract from the paraventricular nucleus (Laqueur).

scholarly journals Potential Role of Medullary Raphe-Spinal Neurons in Cutaneous Vasoconstriction: An In Vivo Electrophysiological Study

2002 ◽  
Vol 87 (2) ◽  
pp. 901-911 ◽  
Author(s):  
Eugene Nalivaiko ◽  
William W. Blessing
Keyword(s):  
Blood Flow ◽  
Electrical Stimulation ◽  
Action Potentials ◽  
Tactile Stimulation ◽  
Central Nucleus ◽  
Nociceptive Stimulation ◽  
Spinal Neurons ◽  
Trigeminal Stimulation ◽  
Cutaneous Blood ◽  
Stimulation Of

In rabbits, raphe magnus/pallidus neurons form a link in the CNS pathway regulating changes in cutaneous blood flow elicited by nociceptive stimulation and activation of the central nucleus of the amygdala. To characterize relevant raphe-spinal neurons, we performed extracellular recordings from the rostral medullary raphe nuclei in anesthetized, paralyzed, mechanically ventilated rabbits. All studied neurons were antidromically activated from the dorsolateral funiculus of the spinal cord (C8–T2). Of 129 studied neurons, 40% were silent. The remaining neurons discharged spontaneously at 0.3–29 Hz. Nociceptive stimulation (lip squeeze with pliers) excited 63 (49%), inhibited 9 (7%), and did not affect 57 (44%) neurons. The same stimulation also elicited falls in ear pinna blood flow. In neurons activated by the stimulation, the increase in discharge preceded the fall in flow. Electrical stimulation of the spinal trigeminal tract excited 61/63 nociception-activated neurons [onset latencies range: 6–75 ms, mean: 28 ± 3 (SE) ms], inhibited 9/9 nociception-inhibited neurons (onset latencies range: 9–85 ms, mean: 32 ± 10 ms), and failed to affect 55/57 neurons insensitive to nociceptive stimulation. Neurons insensitive to nociceptive/trigeminal stimulation were also insensitive to nonnociceptive tactile stimulation and to electrical stimulation of the amygdala. They were either silent (32/45) or discharged regularly at low frequencies. They possessed long-duration action potentials (1.26 ± 0.08 ms) and slow-conducting axons (6.0 ± 0.5 m/s). These neurons may be serotonergic raphe-spinal cells. They do not appear to be involved in nociceptive-related cutaneous vascular control. Of the 63 neurons sensitive to nociceptive and trigeminal tract stimulation, 35 also responded to tactile stimulation (wide receptive field). These neurons possessed short action potentials (0.80 ± 0.03 ms) and fast-conducting axons (30.3 ± 3.1 m/s). In this subpopulation, electrical stimulation of the amygdala activated nearly all neurons tested (10/12), with a mean onset latency of 34 ± 3 ms. The remaining 28 neurons sensitive to nociceptive and trigeminal stimulation did not respond to tactile stimuli and were mainly unaffected by amygdala stimulation. It may be that fast-conducting raphe-spinal neurons, with wide multimodal receptive fields and with input from the central nucleus of the amygdala, constitute the bulbo-spinal link in the CNS pathway regulating cutaneous blood flow in response to nociceptive and alerting stimuli.

EFFECTS OF NEURAL STALK STIMULATION ON PHASIC DISCHARGE OF SUPRAOPTIC NEURONES IN BRATTLEBORO RATS DEVOID OF VASOPRESSIN

1981 ◽  
Vol 90 (2) ◽  
pp. 211-220 ◽  
Author(s):  
G. LENG ◽  
J. WIERSMA
Keyword(s):  
Electrical Stimulation ◽  
Diabetes Insipidus ◽  
Supraoptic Nucleus ◽  
Discharge Pattern ◽  
Brattleboro Rats ◽  
Long Evans ◽  
Discharge Patterns ◽  
Stimulation Of

Brattleboro rats, homozygous for diabetes insipidus, and Long–Evans rats were anaesthetized with urethane, and antidromically identified neurones were recorded from the supraoptic nucleus. Phasically firing neurones were studied during repeated electrical stimulation of the neural stalk, whereby most supraoptic neurones, but not the recorded neurone, were activated antidromically. Such stimulation consistently modified the discharge pattern of phasic neurones in Long–Evans rats, but was relatively ineffective in Brattleboro rats. These results suggest that the effects of neural stalk stimulation on discharge patterns in Long–Evans rats may be substantially mediated by the evoked release of vasopressin or neurophysin.

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