Tabun belongs to the most toxic nerve agents. Its mechanism of action is based on acetylcholinesterase (AChE) inhibition at the peripheral and central nervous systems. Therapeutic countermeasures comprise administration of atropine with cholinesterase reactivators able to reactivate the inhibited enzyme. Reactivation of AChE is determined mostly biochemically without specification of different brain structures. Histochemical determination allows a fine search for different structures but is performed mostly without quantitative evaluation. In rats intoxicated with tabun and treated with a combination of atropine and HI-6, obidoxime, or new oxime K048, AChE activities in different brain structures were determined using biochemical and quantitative histochemical methods. Inhibition of AChE following untreated tabun intoxication was different in the various brain structures, having the highest degree in the frontal cortex and reticular formation and lowest in the basal ganglia and substantia nigra. Treatment resulted in an increase of AChE activity detected by both methods. The highest increase was observed in the frontal cortex. This reactivation was increased in the order HI-6 < K048 < obidoxime; however, this order was not uniform for all brain parts studied. A correlation between AChE activity detected by histochemical and biochemical methods was demonstrated. The results suggest that for the mechanism of action of the nerve agent tabun, reactivation in various parts of the brain is not of the same physiological importance. AChE activity in the pontomedullar area and frontal cortex seems to be the most important for the therapeutic effect of the reactivators. HI-6 was not a good reactivator for the treatment of tabun intoxication.

• MeSH
• acetylcholinesterasa metabolismus   MeSH
• atropin MeSH
• čelní lalok účinky léků   enzymologie   patologie   MeSH
• chemické bojové látky toxicita   MeSH
• cholinesterasové inhibitory aplikace a dávkování   toxicita   MeSH
• GPI-vázané proteiny metabolismus   MeSH
• krysa rodu Rattus MeSH
• LD50 MeSH
• mozek účinky léků   enzymologie   patologie   MeSH
• obidoxim chlorid aplikace a dávkování   farmakologie   terapeutické užití   MeSH
• organofosfáty aplikace a dávkování   antagonisté a inhibitory   toxicita   MeSH
• orgánová specificita MeSH
• oximy aplikace a dávkování   farmakologie   terapeutické užití   MeSH
• potkani Wistar MeSH
• pyridinové sloučeniny aplikace a dávkování   farmakologie   terapeutické užití   MeSH
• reaktivátory cholinesterasy aplikace a dávkování   farmakologie   terapeutické užití   MeSH
• retikulární formace účinky léků   enzymologie   patologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• 1-(4-hydroxyiminomethylpyridinium)-4-(4-carbamoylpyridinium)butane MeSH Prohlížeč
• acetylcholinesterasa MeSH
• Ache protein, rat MeSH Prohlížeč
• asoxime chloride MeSH Prohlížeč
• atropin MeSH
• chemické bojové látky MeSH
• cholinesterasové inhibitory MeSH
• GPI-vázané proteiny MeSH
• obidoxim chlorid MeSH
• organofosfáty MeSH
• oximy MeSH
• pyridinové sloučeniny MeSH
• reaktivátory cholinesterasy MeSH
• tabun MeSH Prohlížeč

Experiments were carried out to determine whether there are separate drives from the selected neuronal networks of the brainstem affecting the discharge patterns of laryngeal and respiratory pump muscles during cough. Twenty-four non-decerebrate spontaneously breathing cats anesthetized with sodium pentobarbitone were used. Microinjections of kainic acid into the lateral tegmental field of the medulla, medullary midline or pontine respiratory group eliminated the cough evoked by mechanical stimulation of the tracheobronchial and laryngopharyngeal mucosa. These stimuli, in most cases, provoked irregular bursts of discharges in the posterior cricoarytenoid and thyroarytenoid laryngeal muscles (or they had no effect on them). No pattern of laryngeal muscle activities following lesions resembled the laryngeal cough response. Lesions of the target regions did not result in any apparent changes in the eupnoeic pattern of laryngeal activity. Neurons of the medullary lateral tegmental field, raphe nuclei and the pontine respiratory group seem to be indispensable for the configuration of the central cough motor pattern. However, these neurons do not appear to be essential for the discharge patterns of laryngeal motoneurons during eupnoea. The residual laryngeal "cough" responses are probably mediated by an additional motor drive.

• MeSH
• anestezie MeSH
• degenerace nervu chemicky indukované   patofyziologie   MeSH
• dýchací centrum fyziologie   MeSH
• dýchací svaly inervace   MeSH
• elektromyografie MeSH
• fyzikální stimulace MeSH
• kašel etiologie   patofyziologie   MeSH
• kočky MeSH
• kyselina kainová MeSH
• laryngální nervy fyziologie   MeSH
• laryngální svaly inervace   MeSH
• medulla oblongata patofyziologie   MeSH
• mozkový kmen patofyziologie   MeSH
• nuclei raphe patofyziologie   MeSH
• pons patofyziologie   MeSH
• zvířata MeSH
• Check Tag
• kočky MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kyselina kainová MeSH

We have tested the hypothesis that neurons of both the ventral reticular nucleus and the adjacent parts of the lateral tegmental field (LTF) may be important for the production of motor programs associated with cough, expiration and aspiration reflexes. Our studies were conducted on non-decerebrate, spontaneously breathing cats under pentobarbitone anesthesia. Dysfunction of the medullary LTF region above the obex, produced by uni- or bilateral injections of kainic acid (a neurotoxin), regularly abolished the cough reflex evoked by mechanical stimulation of both the tracheobronchial and laryngeal regions and in most cases also the expiration reflex induced from the glottal area. However, some electrical activity still occurred in the neurogram of the recurrent laryngeal nerve during probing the laryngeal and glottal regions. Interestingly, the aspiration reflex elicited from the nasopharynx regularly persisted, although with lower intensity after the LTF lesion. Nevertheless, successive midcollicular decerebration performed in four cats also abolished the aspiration reflex. These experiments demonstrate the importance of medullary LTF neurons for the normal occurrence of cough and expiration reflexes. One possible explanation for the elimination of these expulsive processes is that the blockade of the LTF neurons may remove an important source of a facilitatory input to the brainstem circuitries that mediate cough and expiration reflexes. In addition, the potential importance of the mesencephalic reticular formation for the occurrence of the aspiration reflex and the role of the LTF in modulating both the eupnoeic breathing and the blood pressure are also discussed.

• MeSH
• agonisté excitačních aminokyselin MeSH
• anestezie MeSH
• čtvrtá mozková komora MeSH
• decerebrační rigidita MeSH
• degenerace nervu chemicky indukované   patofyziologie   MeSH
• elektromyografie MeSH
• fyzikální stimulace MeSH
• kašel patofyziologie   MeSH
• kočky MeSH
• krevní tlak fyziologie   MeSH
• kyselina kainová MeSH
• mechanika dýchání fyziologie   MeSH
• medulla oblongata patologie   patofyziologie   MeSH
• mezencefalon chirurgie   MeSH
• reflex fyziologie   MeSH
• retikulární formace patologie   patofyziologie   MeSH
• zvířata MeSH
• Check Tag
• kočky MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• agonisté excitačních aminokyselin MeSH
• kyselina kainová MeSH

Localization of the central rhythm generator (CRG) of spontaneous consummatory licking was studied in freely moving rats by microinjection of tetrodotoxin (TTX) into the pontine reticular formation. Maximum suppression of spontaneous water consumption was elicited by TTX (1 ng) blockade of the oral part of the nucleus reticularis gigantocellularis (NRG), whereas TTX injections into more caudal or rostral locations caused significantly weaker disruption of drinking. To verify the assumption that TTX blocked the proper CRG of licking rather than some relay in its output, spontaneously drinking thirsty rats were intracranially stimulated via electrodes chronically implanted into the oral part of the NRG. Lick-synchronized stimulation (a 100-ms train of 0.1-ms-wide rectangular pulses at 100 Hz and 25-150 microA) applied during continuous licking (after eight regular consecutive licks) caused a phase shift of licks emitted after stimulus delivery. The results suggest that the stimulation has reset the CRG of licking without changing its frequency. The reset-inducing threshold current was lowest during the tongue retraction and highest during the tongue protrusion period of the lick cycle. It is concluded that the CRG of licking is located in the oral part of NRG.

• MeSH
• chování při pití účinky léků   fyziologie   MeSH
• elektrická stimulace MeSH
• krysa rodu Rattus MeSH
• mozek anatomie a histologie   účinky léků   fyziologie   MeSH
• periodicita * MeSH
• pudové chování účinky léků   fyziologie   MeSH
• retikulární formace anatomie a histologie   účinky léků   fyziologie   MeSH
• tetrodotoxin aplikace a dávkování   toxicita   MeSH
• zvířata MeSH
• žvýkání účinky léků   fyziologie   MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• tetrodotoxin MeSH

Thresholds for triggering summed auditory evoked responses (ERs) were measured in non-auditory (= extralemniscal--EL) nuclei receiving direct auditory projections from the lateral lemniscus. Primary EL ERs with onset latency of 3-6 ms reflecting activation of direct EL projections of lemniscal auditory nuclei were registered in caudal pontine reticular nucleus (CPRN), in deep layers of superior colliculus (SC) and in ventromedial hypothalamus (VMH). Secondary EL ERs (waves of EL ERs with onset latency above 10 ms) reflecting diffuse auditory EL co-activation of the brain, were registered besides the above mentioned nuclei also in the medial amygdala (MA). Threshold sound intensities for evoking primary EL ERs in CPRN, SC and VMH, for secondary EL ERs in all extralemniscal nuclei tested, and for conditioned avoidance behavior in a two-way shuttle box, were compared mutually. There were no significant mutual differences among thresholds for inducing secondary EL ERs in all EL nuclei tested. Thresholds for evoking secondary EL ERs were lower than those for evoking primary EL ERs in deep layers of the SC, equaled to thresholds for primary EL ERs in the VMH and were higher than thresholds for primary EL ERs in the CPRN. The results suggest that auditory EL projections into SC and/or VMH (but not into CPRN) might represent the primary triggering source for secondary EL ERs in various extralemniscal nuclei. Although conditioning lowered the threshold intensities for inducing secondary EL ERs, the threshold sound intensity for triggering conditioned behavior was lower than the threshold for secondary EL ERs.(ABSTRACT TRUNCATED AT 250 WORDS)

• MeSH
• krysa rodu Rattus MeSH
• mapování mozku MeSH
• mezencefalon fyziologie   MeSH
• nervus vestibulocochlearis fyziologie   MeSH
• pons fyziologie   MeSH
• reakční čas fyziologie   MeSH
• retikulární formace fyziologie   MeSH
• sluchová dráha fyziologie   MeSH
• sluchová percepce fyziologie   MeSH
• sluchové evokované potenciály fyziologie   MeSH
• sluchový práh fyziologie   MeSH
• vnímání hlasitosti fyziologie   MeSH
• vnímání výšky zvuku fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Multichannel EEG, respiration, blood pressure and ECG were recorded during paced breathing at five frequencies in 18 subjects in order to elucidate the effects of paced breathing on power changes in alpha, beta and theta bands, and on rhythmical variability of these parameters. Mean power in the beta band and low-frequency beta power variability (0.12-0.04 Hz) increased during paced breathing at frequencies of 0.25 and 0.20 Hz. The total variability of alpha power in the right parietal and occipital electrodes decreased during paced breathing at 0.1 Hz compared with initial rest. The results point to increased cortical excitability during paced breathing at eupnoeic frequencies and to diminished cortical sensitivity to desynchronizing influences during paced breathing at 0.1 Hz.

• MeSH
• dospělí MeSH
• elektroencefalografie * MeSH
• elektrokardiografie MeSH
• krevní tlak fyziologie   MeSH
• lidé MeSH
• mechanika dýchání fyziologie   MeSH
• neurony fyziologie   MeSH
• retikulární formace cytologie   fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Using a microelectrode with carbon filaments and the voltammetric technique, changes evoked in the catechol oxidation current (CA.OC) and multiple unit activity (MUA) by microinjection of 3-5 microliters 0.5 mol.l-1 KCl were studied in the reticular formation (RF) of the medulla oblongata of anaesthetized rats; the effect of KCl stimulation of the RF and corpus striatum (S) on the CA.OC in these structures was compared. The microinjection of KCl in the vicinity of the working electrode in the RF caused depression of MUA which began 2-3 s after administration, persisted for up to 6 min after and then diminished, reaching control values within 9 min. The voltammetric signal was first recorded in the 1st min after microinjection, when there was an evident decrease in the CA.OC value (59% of the control value); this effect reached its maximum 7 min after administration (a mean drop to 23% of the control), while at the end of the experiment (i.e. after 24 min) CA.OC values had risen to 45-80% of the control value. The response in the S had a biphasic character, however. Immediately after the microinjection (1st min), the mean CA.OC value rose to 626% of the control, while in the second phase (3-10 min) it was seen to fall below the control values (means 21-63% of the control). The differences in the changes evoked by K+ depolarization in the concentration of catecholamines in the RF and S microenvironment are discussed from the aspect of the existence of different pools of the transmitter and other regional differences.(ABSTRACT TRUNCATED AT 250 WORDS)

• MeSH
• buněčná membrána účinky léků   fyziologie   MeSH
• časové faktory MeSH
• chlorid draselný farmakologie   MeSH
• corpus striatum metabolismus   MeSH
• evokované potenciály MeSH
• extracelulární prostor chemie   MeSH
• katecholaminy biosyntéza   MeSH
• krysa rodu Rattus MeSH
• mikroinjekce MeSH
• neurony účinky léků   MeSH
• potkani Wistar MeSH
• retikulární formace metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• chlorid draselný MeSH
• katecholaminy MeSH

Two patients with reflex reticular myoclonus [RRM] were tested electrophysiologically and pharmacologically. In one of the cases the underlying disease was chronic Lyme borreliosis. In the other, the RRM attacks may have been associated with procarbazine therapy applied for Hodgkin's disease. No cortical lesion could be demonstrated either clinically or electrophysiologically [EEG, averaged EEg preceeding the jerks, SSEP]. An EMG analysis of the jerks revealed the shortest latency in the muscles innervated by the accessory nerve. The latencies became longer in a more rostral muscle [masseter], as well as in a more caudal one, the muscles innervated by the facial nerve were spared. it is presumed that the complete movement pattern of the myoclonus residues in the jerk generating structure. RRM in the described cases differs from the startle by sparing the facial nerve and from the Papio papio baboon non-epileptic myoclonus by the activating effect of physostigmine. A partial therapeutic effect was achieved with a serotonine precursor, but a GABAergic therapy proved to be the most effective.

• MeSH
• abnormální reflex * účinky léků   MeSH
• dospělí MeSH
• elektroencefalografie MeSH
• elektromyografie MeSH
• fenobarbital MeSH
• fysostigmin MeSH
• Hodgkinova nemoc komplikace   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mozkový kmen patofyziologie   MeSH
• myoklonus komplikace   patofyziologie   MeSH
• retikulární formace účinky léků   patofyziologie   MeSH
• úleková reakce * účinky léků   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• Názvy látek
• fenobarbital MeSH
• fysostigmin MeSH

The effect of the local administration of noradrenaline (NA) by microinjection into the pontomedullary reticular formation on the startle reaction (SR) evoked by an acoustic stimulus was studied in waking, non-immobilized rats. NA (10(-6) mol.l-1 in 2.5 microliters artificial cerebrospinal fluid) was administered 21 times to five animals in 13 experiments. In nine cases (43%), a significant change in the mean amplitude of the SR to a series of 30 stimuli (recorded in the third minute after administering NA) was observed; in eight cases (38%) it rose and in only one (5%) it fell. Binomial statistics confirmed the preponderance of results with an increase in SR amplitude. The results indicated that the potentiating effect of NA could actively help to regulate the function of the pontomedullary part of the neuronal circuit for the acoustic SR.

• MeSH
• akustická stimulace MeSH
• inbrední kmeny potkanů MeSH
• krysa rodu Rattus MeSH
• medulla oblongata MeSH
• mikroinjekce MeSH
• noradrenalin aplikace a dávkování   farmakologie   MeSH
• pons MeSH
• retikulární formace MeSH
• úleková reakce účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• noradrenalin MeSH

Series of sections from the brain stems of human embryos and adult individuals were studied for the topography and cytoarchitectonics of two different nuclei, both of them referred to in literature as the nucleus Koelliker-Fuse (nucleus K-F). A study of embryonic and comparative materials showed that the original descriptions by Koelliker (1896) and Fuse (1913) were identical with the pars compacta nuclei pedunculo-pontini in present-day nomenclature while the nucleus currently designated with their names was rather related to the principal nucleus of the trigeminus. For that reason, we recommend making a distinction between ncl. K-F (1896, 1913) and ncl. K-F (of recent authors); the former can be used mainly for embryonic material, the latter for comparative studies. However, the ncl. K-F (of recent authors) is not developed in adult humans. Descriptions are also included of the organization of the parabrachial nuclear complex and other structures of the isthmus mesencephali in the human embryo, and both are compared with the situation in adults humans.

• MeSH
• dospělí MeSH
• lidé MeSH
• plod anatomie a histologie   MeSH
• retikulární formace anatomie a histologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH