Electrophysiological and behavioral analysis of lip touch as a component of the food stimulus in the snail Lymnaea.
Electrophysiological and video recording methods were used to investigate the function of lip touch in feeding ingestion behavior of the pond snail Lymnaea stagnalis. Although this stimulus was used successfully as a conditioning stimulus (CS) in appetitive learning experiments, the detailed role of lip touch as a component of the sensory stimulus provided by food in unconditioned feeding behavior was never ascertained. Synaptic responses to lip touch in identified feeding motoneurons, central pattern generator interneurons, and modulatory interneurons were recorded by intracellular electrodes in a semi-intact preparation. We showed that touch evoked a complex but characteristic sequence of synaptic inputs on each neuron type. Touch never simply activated feeding cycles but provided different types of synaptic input, determined by the feeding phase in which the neuron was normally active in the rhythmic feeding cycle. The tactile stimulus evoked mainly inhibitory synaptic inputs in protraction-phase neurons and excitation in rasp-phase neurons. Swallow-phase neurons were also excited after some delay, suggesting that touch first reinforces the rasp then swallow phase. Video analysis of freely feeding animals demonstrated that during normal ingestion of a solid food flake the food is drawn across the lips throughout the rasp phase and swallow phase and therefore provides a tactile stimulus during both these retraction phases of the feeding cycle. The tactile component of the food stimulus is strongest during the rasp phase when the lips are actively pressed onto the substrate that is being moved across them by the radula. By using a semi-intact preparation we demonstrated that application of touch to the lips during the rasp phase of a sucrose-driven fictive feeding rhythm increases both the regularity and frequency of rasp-phase motoneuron firing compared with sucrose applied alone. (+info)
Interarticulator programming in VCV sequences: lip and tongue movements.
This study examined the temporal phasing of tongue and lip movements in vowel-consonant-vowel sequences where the consonant is a bilabial stop consonant /p, b/ and the vowels one of /i, a, u/; only asymmetrical vowel contexts were included in the analysis. Four subjects participated. Articulatory movements were recorded using a magnetometer system. The onset of the tongue movement from the first to the second vowel almost always occurred before the oral closure. Most of the tongue movement trajectory from the first to the second vowel took place during the oral closure for the stop. For all subjects, the onset of the tongue movement occurred earlier with respect to the onset of the lip closing movement as the tongue movement trajectory increased. The influence of consonant voicing and vowel context on interarticulator timing and tongue movement kinematics varied across subjects. Overall, the results are compatible with the hypothesis that there is a temporal window before the oral closure for the stop during which the tongue movement can start. A very early onset of the tongue movement relative to the stop closure together with an extensive movement before the closure would most likely produce an extra vowel sound before the closure. (+info)
Expression of mitogen activated protein kinases in labial salivary glands of patients with Sjogren's syndrome.
OBJECTIVE: The expression of CD40 and CD40 ligand (CD40L) in mononuclear cells (MNCs) infiltrating the salivary glands of patients with Sjogren's syndrome (SS) has recently been reported. This study determined the expression of mitogen activated protein kinase (MAP kinase) superfamilies, which act as downstream effector molecules of CD40, in MNCs infiltrating labial salivary tissues in SS patients. METHODS: Six HTLV-I seronegative SS patients and 10 HTLV-I seropositive patients including five HTLV-I associated myelopathy (HAM) patients were examined. The expression of MAP kinase superfamilies in labial salivary glands was examined by immunohistochemistry containing the mirror section technique. RESULTS: Both active forms of c-Jun N-terminal kinase (JNK) and p38 were found in salivary infiltrating MNCs of SS patients. Only minimal expression of the active form of extracellular signal regulated kinase (ERK) was observed in these tissues, however, co-expression of active JNK and active p38 was confirmed by the mirror section technique. Furthermore, these protein kinases were co-expressed in CD40(+) MNCs. No difference in expression levels of active JNK and p38 was found in patients who were positive or negative for anti-HTLV-I antibody. CONCLUSION: These results indicate that JNK and p38, but not ERK, function as downstream effector molecules of CD40 in salivary infiltrating MNCs in SS patients, and suggest that these molecules may be involved in the pathological process of chronic sialadenitis in SS. (+info)
Low-intensity laser therapy is an effective treatment for recurrent herpes simplex infection. Results from a randomized double-blind placebo-controlled study.
Recurrent infection with herpes simplex virus is a common disease. Recently, alternative therapies have been introduced. Among those, low-intensity laser therapy mainly used for the acceleration of wound healing and in pain therapy has previously been shown to be of benefit in herpes zoster infections. In this study we evaluated the influence of low-intensity laser therapy (wavelength 690 nm, intensity: 80 mW per cm2, dose: 48 J per cm2) in 50 patients with recurrent perioral herpes simplex infection (at least once per month for more than 6 mo) in a randomized, double-blind placebo-controlled trial design. Patients in the laser group received daily irradiations for 2 wk, whereas patients in the placebo group were sham-irradiated. After completion of the laser/sham treatment, patients were asked to return to the Department of Dermatology, University of Vienna Medical School at the time of recurrence. All except two patients completed the study and were monitored for 52 wk. The median recurrence-free interval in the laser-treated group was 37.5 wk (range: 2-52 wk) and in the placebo group 3 wk (range: 1-20 wk). This difference was found to be statistically significant (p < 0.0001; Wilcoxon's Rank Sum Test). In conclusion, we demonstrated that a total of 10 irradiations with low-intensity laser therapy significantly lowers the incidence of local recurrence of herpes simplex infection. Since this athermic phototherapeutic modality represents a safe, noninvasive treatment, it might be considered as an alternative to established therapeutic regimens in this indication. (+info)
Functional roles played by the sympathetic supply to lip blood vessels in the cat.
In the anesthetized cat we used laser-Doppler flowmetry to investigate the part played by cervical superior sympathetic trunk (CST) fibers in the control of blood vessels in an orofacial area (the lower lip). The blood flow increase (antidromic vasodilatation) elicited by inferior alveolar nerve (IAN) stimulation was not affected by ongoing repetitive CST stimulation over the frequency range examined (0.2-10 Hz), although reflex parasympathetic vasodilatation was attenuated. The vasoconstrictor responses elicited by IAN stimulation in some preparations were reduced in a frequency-dependent manner (at 0.2-1 Hz) during ongoing CST stimulation (and replaced by vasodilator responses). The vasoconstrictor response evoked directly by brief CST stimulation was attenuated, but not transformed to a vasodilator response, by ongoing CST stimulation. Thus in the cat lower lip 1) sympathetic stimulation attenuated one type of vasodilator response (parasympathetic-mediated vasodilatation), but not another (antidromic vasodilatation), and 2) ongoing sympathetic (CST) stimulation at low frequencies (<1 Hz) prevented further sympathetic-mediated vasoconstriction. (+info)
Role of thalamic axons in the expression of H-2Z1, a mouse somatosensory cortex specific marker.
In the H-2Z1 mouse line, postnatal expression of the lacZ containing transgene in the cerebral cortex is restricted to layer IV neurons of the somatosensory area. We have used H-2Z1 embryos in previous heterotopic transplantation experiments to investigate the chronology of determination of areal identity. From the onset of neurogenesis, the cortex was regionalized in domains fated to express or not the somatosensory area-specific transgene. Determination occured 1 day later. In the present study, we show that, in vivo, H-2Z1 expression coincides with invasion of the cortical plate by thalamic afferents. We therefore investigated the role of thalamic innervation in the onset of H-2Z1 expression. For this purpose, we examined the pattern of H-2Z1 expression in perinatal cortical explant, in reeler mutant and MaoA deficient mice, or in animals which had received neonatal lesions affecting the somatosensory cortex or the thalamocortical projection. We found that, around birth, a switch occurs in the control of H-2Z1 expression: whereas H-2Z1 expression developed autonomously in embryonic parietal cortex in the absence of thalamic fibers, a transient requirement for a thalamic axon derived signal was observed postnatally. This property has interesting implications for the plasticity of cortical areas in development and evolution. (+info)
A preliminary gene map for the Van der Woude syndrome critical region derived from 900 kb of genomic sequence at 1q32-q41.
Van der Woude syndrome (VWS) is a common form of syndromic cleft lip and palate and accounts for approximately 2% of all cleft lip and palate cases. Distinguishing characteristics include cleft lip with or without cleft palate, isolated cleft palate, bilateral lip pits, hypodontia, normal intelligence, and an autosomal-dominant mode of transmission with a high degree of penetrance. Previously, the VWS locus was mapped to a 1.6-cM region in 1q32-q41 between D1S491 and D1S205, and a 4.4-Mb contig of YAC clones of this region was constructed. In the current investigation, gene-based and anonymous STSs were developed from the existing physical map and were then used to construct a contig of sequence-ready bacterial clones across the entire VWS critical region. All STSs and BAC clones were shared with the Sanger Centre, which developed a contig of PAC clones over the same region. A subset of 11 clones from both contigs was selected for high-throughput sequence analysis across the approximately 1.1-Mb region; all but two of these clones have been sequenced completely. Over 900 kb of genomic sequence, including the 350-kb VWS critical region, were analyzed and revealed novel polymorphisms, including an 8-kb deletion/insertion, and revealed 4 known genes, 11 novel genes, 9 putative genes, and 3 psuedogenes. The positional candidates LAMB3, G0S2, HIRF6, and HSD11 were excluded as the VWS gene by mutation analysis. A preliminary gene map for the VWS critical region is as follows: [see text] 41-TEL. The data provided here will help lead to the identification of the VWS gene, and this study provides a model for how laboratories that have a regional interest in the human genome can contribute to the sequencing efforts of the entire human genome. (+info)
The physiologic development of speech motor control: lip and jaw coordination.
This investigation was designed to describe the development of lip and jaw coordination during speech and to evaluate the potential influence of speech motor development on phonologic development. Productions of syllables containing bilabial consonants were observed from speakers in four age groups (i.e., 1-year-olds, 2-year-olds, 6-year-olds, and young adults). A video-based movement tracking system was used to transduce movement of the upper lip, lower lip, and jaw. The coordinative organization of these articulatory gestures was shown to change dramatically during the first several years of life and to continue to undergo refinement past age 6. The present results are consistent with three primary phases in the development of lip and jaw coordination for speech: integration, differentiation, and refinement. Each of these developmental processes entails the existence of distinct coordinative constraints on early articulatory movement. It is suggested that these constraints will have predictable consequences for the sequence of phonologic development. (+info)