Relationship between dyspnea in daily life and psycho-physiologic state in patients with chronic obstructive pulmonary disease during long-term domiciliary oxygen therapy

We examined the relationships among dyspnea ratings in daily life, the physiologic state, and anxiety and depression of fifty-two patients with chronic obstructive disease (COPD) during long-term domiciliary oxygen therapy (LTOT). Clinical ratings of dyspnea were assessed by the visual-analog scale (VAS) during eight types of basic behavior in indoor daily life. Analysis of the physiologic state included forced expiratory volume in 1 second (FEV1.0), and arterial blood gas (PaO2, PaCO2) at rest while breathing room air. The hospital anxiety and depression (HAD) scale, which consists of 14 questions, was used to assess the degree of anxiety (HAD-A) and depression (HAD-D). The mean age of the patients was 69.5 +/- 10.8 year (SD), and the duration of LTOT was 944 +/- 739 days. The mean values were 0.77 +/- 0.45 L for FEV1.0, 57.7 +/- 7.4 Torr for PaO2, and 47.4 +/- 8.1 Torr for PaCO2. FEV1.0 was correlated with PaCO2(r = -0.548, p < 0.0001), but it was not correlated with PaO2. High correlation was noted between HAD-A and HAD-D (r = 0.693, P < 0.0001), whereas correlation was not noted between HAD and the physiologic state. VAS was significantly correlated with FEV1.0 (r = 0.320, p < 0.05), as well as with HAD-A (r = 0.358, p < 0.01) and HAD-D (r = 0.444, p < 0.01). Dyspnea ratings were found to be influenced by anxiety and the depression state, and also by the degree of flow limitation in patients with COPD during LTOT. In contrast, the physiologic state scarcely influenced the anxiety and depression state. Thus, psychotherapy may play an important role in the reduction of dyspnea sensation, which is an important determinant of quality of life.

High prevalence of Ancylostoma spp. infection in dogs, associated with endemic focus of human cutaneous larva migrans, in Tacuarembo, Uruguay

A helminthological survey of the intestinal parasites in stray dogs was conducted in urban and suburban area of Tacuarembó, Uruguay, during winter time. Eighty stray dogs captured in the city were necropsied. Seventy nine dogs (98.8%) were positive for helminth infection. Seventy seven (96.3%) were parasitized by hookworms. Two species of hookworms were found: Ancylostoma caninum 96.3% and A. braziliense 49.4%. This is the first report of the prevalence of A. braziliense in Uruguay. Considering that incidences of human cutaneous larva migrans caused by the migration of hookworms larvae were restricted mainly to the northern part of Uruguay and that only A. caninum were reported to be prevalent in the southern part, it is supposed that A. braziliense is the primary causative agent of human cutaneous larva migrans in Uruguay.

Parenteral strobilar development of Echinococcus multilocularis in scid mice

Parenteral strobilation of Echinococcus multilocularis was observed in acid (severe combined immuno-deficient) mice after intracerebral, subcutaneous and intraperitoneal inoculation with protoscoleces. Evaginated protoscoleces and segmented worms were obtained at the inoculated sites. Most worms recovered from peritoneal cavity of scid mice were encapsulated by connective tissue and granulocytes but showed a maximum of 3 proglottids, elongation of genital primordia and vesiculation. Viability of worms recovered from the subcutaneous tissue and peritoneal cavity of scid mice were higher (69.1-91.4%) than those from the immunologically normal C.B-17 (4.0-48.0%) control mice. However, viabilities of worms from the cerebrum of both scid and C.B-17 were almost the same (87.7-94.4%). Worms recovered from scid mice showed further development of reproductive organs when transplanted into the small intestine of prednisolone treated golden hamster. These findings suggest that the parenteral milieu of scid mice allows adult development of E. multilocularis protoscoleces.

Typing of verotoxins by DNA colony hybridization with poly- and oligonucleotide probes, a bead-enzyme-linked immunosorbent assay, and polymerase chain reaction

To identify the type of Verotoxins (VT) produced by Verocytotoxin-producing Escherichia coli (VTEC), a sensitive bead-enzyme-linked immunosorbent assay and polymerase chain reaction with common and specific primers to various VTs (VT1, VT2, VT2vha, VT2vhb, and VT2vp1) were developed. Together with colony hybridization tests with oligo- and polynucleotide probes, these methods were applied to VTEC isolates to type the VT produced. The toxin types of 26 of 37 strains were identified, but the reaction profiles in assays of the remaining 11 strains suggested the existence of new VT2 variants. The application of these identification procedures may be useful as a tool for clinical and epidemiological studies of VTEC infection.

Alveolar hydatidosis in a gorilla and a ring-tailed lemur in Japan

Alveolar hydatidosis by Echinococcus multilocularis (Em) infection occurred on a 22-year-old (approx.) male gorilla (Gorilla gorilla) and a 4-year-old female ring-tailed lemur (Lemur catta) in a zoo, in Hokkaido, Japan. Case 1: The gorilla presented neurologic signs in course of nine months and died. Pathologically, alveolar hydatid lesions were found in the liver, the liver-associated lymph nodes, the cerebrum, and the lungs. A protoscolex was found only in one hepatic cyst. Case 2: In the lemur, large masses of hydatide cysts were found on the liver and at the lung-associated lymph nodes. Cysts contained numerous calcareous corpuscles and protoscolices. The lemur appears a favorable intermediate-host for Em. The identification of Em in both cases were confirmed by PCR.

Participation of platelets in protection against larval Taenia taeniaeformis infection in mice

The participation of platelets in the protection against larval Taenia taeniaeformis was studied. CB-17 SCID mice, susceptible to T. taeniaeformis, were protected against a challenge infection with T. taeniaeformis by the passive transfer of platelets from T. taeniaeformis-infected normal CB-17 mice, resistant to T. taeniaeformis.

Effects of willful ventilatory control on respiratory sensation during hypercapnia

Remarkable augmentation of breathing discomfort has been noted when ventilation is constrained to the steady state level during progressive hypercapnia. However, the effect of willful enhancement of ventilation on breathing discomfort remains to be evaluated. The present study examined the effects of moderate willful increases or decreases in ventilation during progressive hypercapnia on breathing discomfort in 12 subjects. There were a total of 5 rebreathing trials. In the first (F1) and the fifth trials the subjects rebreathed freely. In the other trials subjects breathed by tracking a target to achieve hypercapnic ventilatory responses that were the same (HCVR-S), 25% higher (HCVR-H) and 25% lower (HCVR-L) than in the F1 trial. Breathing discomfort was assessed every 30 s by a 150-mm visual analog scale (VAS). The sensational response (dVAS/dPCO2) during HCVR-S [3.8 +/- (SE) 0.8 mm/Torr] was significantly smaller (p < 0.01) than that during the F1 (6.3 +/- 0.8 mm/Torr) trial. HCVR-H resulted in a further decrease in dVAS/dPCO2 to 3.1 +/- 0.7 mm/Torr as compared to HCVR-S (p < 0.05). HCVR-L significantly increased dVAS/dPCO2 to 4.9 +/- 0.7 mm/Torr compared to HCVR-S (p < 0.05). The final free rebreathing ventilatory response was significantly larger than the initial free rebreathing response (2.7 +/- 0.5 as compared to 2.1 +/- 0.4 liters/min/Torr, p < 0.01). However, the sensational response did not change (6.3 +/- 0.8 vs. 5.8 +/- 0.7 mm/Torr). These rebreathing studies indicate that willful control of respiration decreases respiratory sensation even at comparable levels of ventilation. In particular, moderate willful increases in ventilation produce an ameliorating effect on the sensation of breathing discomfort.

Age-related changes in the static and dynamic mechanical properties of mouse lungs

To investigate the effects of aging on pulmonary mechanical properties in mice, we devised a new experimental apparatus to measure the respiratory impedance of excised lungs in mice and examined age-related changes in both static and dynamic properties. In an accelerated senescence-resistant strain of mice, SAMR1 (Takeda, T., Y. Fukuchi, Y. Uejima, K. Teramoto, T. Oka and H. Orino, J. Am. Geriatr. Soc. 39: 911-919, 1991), ranging from 3 to 24 months of age, static compliance (Cst) as well as total lung capacity increased significantly with age, whereas specific compliance and the K value, as determined by exponential analysis, showed no significant change. In the dynamic study, dynamic compliance (Cdyn) increased significantly with age, whereas the frequency dependence of Cdyn (Cdyn/Cst) did not vary with age. From these results we concluded that lung elasticity, normalized to lung volume, remained constant with age and that the effects of aging on pulmonary mechanics might be solely derived from increases in lung volume in the SAMR1 strain of mice.

Nematodes of armadillos in Paraguay: a description of a new species Aspidodera esperanzae (Nematoda: Aspidoderidae)

Twelve species of nematodes comprising 9 genera were recovered from the gastrointestinal tract of 2 Euphractus sexcinctus and 2 Dasypus novemcinctus captured in the Department of San Pedro, Paraguay. All armadillos were infected with 1 or more species of nematode. The following nematodes were recovered: Mazzia mazzia, Spirura guianensis, Trichohelix tuberculata, Ancylostoma sp., Moennigia complexus, Moennigia pintoi, Ascaris dasypodina, Cruzia tentaculata, Aspidodera fasciata, Aspidodera scoleciformis, Aspidodera esperanzae n. sp., and Heterakinae gen. sp. This report describes a new species of the Aspidodera nematode, Aspidodera esperanzae n. sp., the first species to be reported bearing cephalic cordons made up of 7 longitudinal loops in the subfamily of Aspidoderinae. This study also documents a new host record for S. guianensis and shows a new geographical distribution in Paraguay for M. mazzia, S. guianensis, T. tuberculata, M. complexus, and M. pintoi.

Antibody production in Syphacia obvelata infected mice

Antibody response to Syphacia obvelata infection was observed in AKR/J mice by ELISA. Experimental infection with the pinworm eggs showed the presence of specific IgG against S. obvelata somatic antigens at 12 days postinfection, and that it increased steadily thereafter. Sera of S. obvelata-infected mice showed cross-reactivity with somatic antigens of other Syphacia species such as S. mesocriceti and S. muris, but not with Aspiculuris asiatica. Western blotting of S. obvelata antigen with sera of S. obvelata-infected mice showed a corresponding increase in the number of bands during the course of infection. Infected mice showed significantly higher antibody production to sheep red blood cells than the uninfected control mice. Thus, S. obvelata infection is shown to alter the humoral response to nonparasitic antigenic stimuli. These observations indicate that infection by helminths, which apparently do not produce clinical symptoms, might modulate the immune system of the host and, therefore, affect experimental results.

Model of respiratory sensation and wilful control of ventilation

A mathematical model has been developed that includes sensations of breathlessness and a dynamic CO2 respiratory controller. Breathing sensations, which are represented as a discomfort index, are assumed to depend on arterial PCO2 level, automatic and wilful motor commands and mechanoreceptor feedback. Wilful control is assumed to arise from cortical centres of the brain and is independent of the reflex control system. The bulbopontine respiratory controller produces the automatic motor command, which is determined by chemical and mechanical feedback. Simulations demonstrate how the controller output and breathing sensations change when wilful motor commands disturb spontaneous breathing. Simulations include isocapnic hyper- and hypoventilation and deliberate hypoventilation during CO2 rebreathing. Simulations are compared with experimental data from human subjects. Simulations predict that the discomfort index intensifies when ventilation is either voluntarily raised or lowered from the optimal level; and discomfort is greater when ventilation is lowered than when it is raised at a given level of PCO2. The simulated results agree with those obtained experimentally. The simulations suggest that respiratory drive integration may depend not only on the direct effects of chemical and mechanical feedback, but also on the perceptual consequences of these stimuli.

Application of DNA fingerprinting with digoxigenated oligonucleotide probe (CAC)5 to analysis of the genetic variation within Taenia taeniaeformis

DNA from T. taeniaeformis digested with the restriction endonuclease was hybridized with digoxigenated oligonucleotide probe (CAC)5. Metacestode and adult showed same clear multibanding patterns, which were characteristic of multilocus DNA fingerprinting. The fingerprinting patterns were quite different from those of the rodent hosts. Genetic variations in 4 laboratory-reared isolates of T. taeniaeformis, including 3 isolates which have been reported to be indistinguishable by infectivity, morphology and protein composition of metacestode, were investigated using this technique. Each of the 4 isolates exhibited isolate-specific fingerprinting patterns and were easily distinguished from one another, thus it was considered that (CAC)5 was a highly resolvable and informative probe for cestodes. However, it was also indicated that (CAC)5 was so sensitive that applying fingerprinting with (CAC)5 to taxonomical or phylogenetic analysis was limited where habitat of the host was restricted to the small area. In comparison to fingerprinting with 32P-labeled (CAC)5, fingerprinting with digoxigenated (CAC)5 represented more and sharper bands. It was considered that a digoxigenated probe was more useful for genetic analysis of cestodes.

Intraspecific variation of isoenzymes in Taenia taeniaeformis

The technique of isoenzyme electrophoresis was applied to Japanese wild populations of Taenia taeniaeformis (isolated from Norway rats) and three laboratory reared isolates (KRN isolated from a Malaysian Norway rat, BMM from a Belgian house mouse and ACR from a Japanese gray red-backed vole). The average heterozygosities of Japanese wild populations were fairly small and total genetic variability was 0.0499. The genetic make-up of T. taeniaeformis in Norway rats was rather uniform in the whole of Japan. In KRN isolate, each of all 10 loci examined possessed the allele which was predominant in Japanese wild populations. Similarly, each of 9 loci in BMM isolate possessed the same alleles, but one of 2 alleles at HK locus was different from that in the others. T. taeniaeformis parasitizing house mice and rats were considered to be genetically closely related to each other. In ACR isolate, 7 out of 10 loci possessed different alleles from those in the other populations. It was considered that ACR isolate was genetically distant and its phylogenetic origin in Japan should be different from worms parasitizing Norway rats.

Paradoxical phase response at late expiration by superior laryngeal nerve stimulation

Superior laryngeal nerve (SLN) stimulation during expiration prolongs the respiratory cycle in decerebrate, vagotomized and paralysed cats. In a few animals, however, the cycle can be terminated prematurely by the same stimulus. We developed a mathematical model of the respiratory neural network to stimulate these responses. The model contained inspiratory decrementing (I-DEC), and augmenting (I-AUG) and expiratory decrementing (E-DEC), and augmenting (E-AUG) neurones. Connections were based on published findings. SLN stimulation during late expiration prolonged the cycle when it was assumed to excite principally E-DEC neurones, whereas it terminated the cycle prematurely when it was assumed to excite both I-DEC and E-DEC neurones. Therefore, phase-resetting depends on the differential strength of afferent connections on the network's elements.

Intraspecific variation of Taenia taeniaeformis as determined by various criteria

The intraspecific variation of four laboratory-reared isolates of Taenia taeniaformis the SRN and KRN isolates from Norway rats, Rattus norvegicus, captured in Japan and Malaysia, respectively; the BMM isolated from a house mouse, Mus musculus, captured in Belgium; and the ACR isolate from a gray red-backed vole, Clethrionomys rufocanus bedfordiae, captured in Japan was examined by various criteria. Eggs of each of the four isolates were orally inoculated into several species of intermediate host. They were most infective to the rodent species from which the original metacestode of each isolate had been isolated in the field, and only the ACR isolate was infective to the gray red-backed vole. Although little difference was found between the SRN, KRN, and BMM isolates by the other criteria, including the morphology of rostellar hooks, the protein composition of the metacestode, and restriction endonuclease analysis of DNA, the ACR isolate was clearly different from the others. It was considered that the ACR isolate was independent as a strain distinct from the other three isolates.

Activity of bulbar respiratory neurons during fictive coughing and swallowing in the decerebrate cat

1. The behaviour of medullary respiratory neurons was studied during fictive coughing and swallowing evoked by electrical stimulation of the superior laryngeal nerve (SLN) in decerebrate, paralysed and artificially ventilated cats. Fictive coughing, swallowing and respiration were monitored by recording activities of the phrenic, hypoglossal and abdominal nerves. 2. Extracellular recordings were made from respiratory neurons in the ventral respiratory group (VRG) and in the Bötzinger complex (BOT). The neuronal types analysed included decrementing inspiratory neurons (I-DEC), augmenting expiratory neurons (E-AUG) and decrementing expiratory neurons (E-DEC) from the BOT area, and augmenting inspiratory neurons (I-AUG) and augmenting expiratory neurons (E-AUG) from the VRG area. 3. During fictive coughing, all the inspiratory and expiratory neurons were active during the inspiratory and expiratory phases of coughing, respectively. The firing of both I-DEC and I-AUG neurons was increased and prolonged in association with the augmented inspiratory activity of the phrenic nerve. The activity of E-AUG neurons of the VRG did not parallel the abdominal nerve activity, suggesting the existence of additional neurons which participate in the generation of abdominal nerve activity during fictive coughing. 4. During fictive swallowing, half of I-DEC neurons fired transiently at the onset of hypoglossal bursts associated with swallowing; the firing was suppressed during the rest of the hypoglossal bursts. Other I-DEC neurons were silent during hypoglossal bursts. Some I-AUG neurons fired during the initial half of hypoglossal bursts, and others were silent. The brief phrenic activity accompanying the swallowing might have originated from this activity in I-AUG neurons. The discharges of all E-AUG neurons (BOT and VRG) and the majority of E-DEC BOT neurons were suppressed during swallowing. 5. We conclude that these five types of respiratory neurons of the BOT and VRG are involved in the generation of the spatiotemporally organized activity of coughing and swallowing, and that at least a part of the neuronal network for respiration is shared by networks for these non-respiratory activities.

Developmental and morphological characteristics of Taenia taeniaeformis (Batsch, 1786) in Clethrionomys rufocanus bedfordiae and Rattus norvegicus from different geographical locations

Developmental and morphological characteristics of 3 isolates of Taenia taeniaeformis isolated from Clethrionomys rufocanus bedfordiae in Abuta (70 km southwest of Sapporo), Japan (isolate ACR), and from Rattus norvegicus in Sapporo, Japan (isolate SRN) and Kuala Lumpur, Malaysia (isolate KRN) were compared. Eggs of 3 isolates were administered to several species of rodents. Isolate ACR infected C. rufocanus bedfordiae, Apodemus speciosus, and Apodemus argenteus, but not rats or mice, whereas isolate SRN and isolate KRN were infective to rats, mice, A. speciosus, and A. argenteus, but not to C. rufocanus bedfordiae. The increase in cyst size of isolate ACR continued during the experimental period, whereas that of the other 2 isolates had ceased growing after 30 days postinfection. However, significant differences were observed in the length of the small rostellar hooks, number and distribution of testes, and the length of the cirrus sac between isolate ACR and the other 2 isolates. Thus it is suggested that isolate ACR is a distinct strain or even a new species.

Infectivities of four isolates of Taenia taeniaeformis to various rodents

Taenia taeniaeformis were isolated from Norway rats captured at Sapporo (SRN isolate) and Kuala Lumpur, Malaysia (KRN) and from Bedford's gray red-backed voles at Toubetsu (TCR) and Abuta (ACR). SRN, KRN and TCR isolates showed similar degree of infectivity to various rodents in which cysticerci with hooks were obtained in laboratory rats, white tuberous lesions in mice and no cysts or lesions in Mongolian gerbils and voles. Contrary to this, inoculation with ACR isolate eggs resulted in strobilocerci formation in the liver of voles, but no cysts were observed in rats, mice or gerbils. This host specificity of ACR isolate to voles suggests that it might be a new species of Taenia.

Long-term effects of radiation for medulloblastoma on intellectual and physical development. A case report of monozygotic twins

BACKGROUND

Recent advances in treatment have improved the prognosis for medulloblastoma. Although postoperative radiation of the central nervous system (CNS) is widely practiced, late radiation sequelae, especially in long-term survivors, pose a constant risk.

METHODS

To assess the long-term effects of CNS radiation, a monozygotic twin girl with medulloblastoma was compared with her normal twin. Treatment included total removal of the mass, postoperative chemotherapy, and CNS radiation with 47.8 Gy directed to the posterior fossa, 30.2 Gy to the cerebral hemispheres, and 20 Gy to the whole spine.

RESULTS

Not only the radiated patient's spine but also the unradiated upper and lower limbs were shorter than the control subject's. The patient's thyroid hormone level was within normal range; however, thyroid-stimulating hormone was higher than normal. The patient's intellectual ability deteriorated, and cognitive dysfunction has not improved as of 6 years after treatment.

CONCLUSIONS

Treatment systems that do not cause late sequelae affecting physical and intellectual development should be pursued.

Animal reservoirs for Trypanosoma cruzi infection in an endemic area in Paraguay

Animal reservoirs for Trypanosoma cruzi infection were investigated in 5 communities in the Department of San Pedro, currently one of Paraguay's most highly endemic areas. A total of 112 domestic animals (37 cattle, 2 horses, 1 ass, 20 pigs, 44 dogs and 8 cats) and 4 wild animals (1 white-eared opossum, 2 yellow armadillos and 1 common long-nosed armadillo) were examined for blood. Although no trypomastigotes were found by 2 direct observation methods, the microhaematocrit and Giemsa stained thick and thin smears methods, several forms of trypanosoma flagellates morphologically identical to T. cruzi were detected in the liver infusion tryptose (LIT) medium from a single sample taken from a yellow armadillo, Euphractus sexicintus. When serum samples of all the animals were examined for antibody to T. cruzi by direct agglutination (DA) test, 3 cattle, 2 pigs, 16 dogs and 3 cats had positive titers (1:32 or greater), but no wild animals showed positive reactions. T. cruzi was not found by culture nor microscopic examination of samples from any of the seropositive animals. However, domestic animals such as cattle, pigs, dogs and cats which were found to be seropositive in this study, possibly act as an animal reservoir in this endemic area as well as armadillos in which T. cruzi was observed.

Alpha 1-adrenoceptors in the conduction system of rat hearts

1. We have characterized alpha 1-adrenoceptor in the conduction systems of the rat heart by quantitative autoradiography. 2. Consecutive 20 micron thick sections from a single rat heart containing the sinoatrial (SA) node and atrioventricular (AV) node were incubated with increasing concentrations of [3H]-prazosin with or without 10 microM phentolamine. After exposure to 3H-Ultrofilm, optical densities corresponding to the SA node and AV node were determined by computerized densitometry after comparison with 3H standards. 3. The SA node and AV node were stained heavily for cholinesterase and they contained a higher concentration of alpha 1-adrenoceptors than the adjacent myocardium without a significant change in the affinity. 4. These results support the hypothesis that alpha 1-adrenoceptors may play an important role not only in inotropism but also in chronotropism of rat hearts.

Infection course of the strobilar stage of Taenia crassiceps in golden hamsters, with reference to host responses

The time course of intestinal infection of golden hamsters (Mesocricetus auratus) with Taenia crassiceps was monitored every 2 days up to day 26 postinfection (p.i.). The isolate used was originally obtained from Clethrionomys rutilus on St. Lawrence Island, Bering Sea (USA), and shows a high level of enteral establishment without parenteral infection. Following oral administration of various numbers (3, 15, 30, or 60) of metacestodes, proportional numbers of cestodes attached their scolices to the mucosa of the middle (one-third) segment of the small intestine. Except for animals given 3 metacestodes, dislocation of cestodes to the posterior parts of the intestine was noted on days 10-14 p.i. and began faster in animals that had received larger numbers of metacestodes. Concurrent with dislocation or elimination of cestodes, there existed distinct increases in intestinal eosinophil peroxidase and myeloperoxidase activities. The number of mast cells in the lamina propria peaked on day 16 p.i., and specific serum IgG began to increase within 1 week p.i. The level of all these changes was dose-dependent. In prednisolone-treated animals that received 60 metacestodes, dislocation of cestodes was not evident, and mucosal inflammatory changes were suppressed to a considerable extent. The findings of this study are discussed as a model for the study of canine taeniasis.

Location and axonal projection of one type of swallowing interneurons in cat medulla

Extracellular recordings were made from a type of relay neurons of the superior laryngeal nerve (SLN) afferents in the vicinity of the retrofacial nucleus (RFN) in either pentobarbitone-anesthetized or unanesthetized and decerebrate cats, which were paralyzed and artificially ventilated. A total of 26 neurons that could be activated both orthodromically by electrical stimulation of the SLN and antidromically by stimulation of the brainstem were analyzed. All 26 neurons were activated from the ipsilateral SLN and 13 were activated from the contralateral SLN with mean latencies of 7.7 ms and 11.4 ms, respectively. The majority of these neurons were located in the parvocellular reticular formation dorsomedial to the RFN and to the rostral part of the nucleus ambiguus (AMB). Antidromic stimulation of the medulla showed that 22 of the 26 neurons projected to the hypoglossal nucleus (HYP) and 19 neurons tested projected to the AMB. Of these, 15 neurons projected to both the HYP and AMB and two projected to the lateral reticular nucleus as well. Seventeen neurons were tested for their behavior during fictive swallowing which was elicited by continual electrical stimulation of the SLN and monitored by the activity of the hypoglossal nerve. Twelve neurons showed brief (100-200 ms) burst firing at the onset of swallowing; the firing of the other 5 neurons were suppressed during swallowing. Both the swallowing-active and swallowing-inactive neurons projected to the HYP and AMB. Thus, the SLN relay neurons in the vicinity of the RFN might participate in the early stage of SLN-induced swallowing by integrating inputs from SLN afferents.