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PubMed2006

FMRI lateralization of expressive language in children with cerebral lesions.

PURPOSE: Lateralization of language function is crucial to the planning of surgery in children with frontal or temporal lobe lesions. We examined the utility of functional magnetic resonance imaging (fMRI) as a determinant of lateralization of expressive language in children with cerebral lesions. METHODS: fMRI language lateralization was attempted in 35 children (29 with epilepsy) aged 8-18 years with frontal or temporal lobe lesions (28 left hemisphere, five right hemisphere, two bilateral). Axial and coronal fMRI scans through the frontal and temporal lobes were acquired at 1.5 Tesla by using a block-design, covert word-generation paradigm. Activation maps were lateralized by blinded visual inspection and quantitative asymmetry indices (hemispheric and inferior frontal regions of interest, at p<0.001 uncorrected and p<0.05 Bonferroni corrected). RESULTS: Thirty children showed significant activation in the inferior frontal gyrus. Lateralization by visual inspection was left in 21, right in six, and bilateral in three, and concordant with hemispheric and inferior frontal quantitative lateralization in 93% of cases. Developmental tumors and dysplasias involving the inferior left frontal lobe had activation overlying or abutting the lesion in five of six cases. fMRI language lateralization was corroborated in six children by frontal cortex stimulation or intracarotid amytal testing and indirectly supported by aphasiology in a further six cases. In two children, fMRI language lateralization was bilateral, and corroborative methods of language lateralization were left. Neither lesion lateralization, patient handedness, nor developmental versus acquired nature of the lesion was associated with language lateralization. Involvement of the left inferior or middle frontal gyri increased the likelihood of atypical language lateralization. CONCLUSIONS: fMRI lateralizes language in children with cerebral lesions, although caution is needed in interpretation of individual results.

Adolescent↗
PubMed2005

Laterality of brain areas associated with arithmetic calculations revealed by functional magnetic resonance imaging.

BACKGROUND: Asymmetry of bilateral cerebral function, i.e. laterality, is an important phenomenon in many brain actions: arithmetic calculation may be one of these phenomena. In this study, first, laterality of brain areas associated with arithmetic calculations was revealed by functional magnetic resonance imaging (fMRI). Second, the relationship among laterality, handedness, and types of arithmetic task was assessed. Third, we postulate possible reasons for laterality. METHODS: Using a block-designed experiment, twenty-five right-handed and seven left-handed healthy volunteers carried out simple calculations, complex calculations and proximity judgments. T1WI and GRE-EPI fMRI were performed with a GE 1.5T whole body MRI scanner. Statistical parametric mapping (SPM99) was used to process data and localize functional areas. Numbers of activated voxels were recorded to calculate laterality index for evaluating the laterality of functional brain areas. RESULTS: For both groups, the activation of functional areas in the frontal lobe showed a tendency towards the nonpredominant hand side, but the functional areas in the inferior parietal lobule had left laterality. During simple and complex calculations, the laterality indices of the prefrontal cortex and premotor area were higher in the right-handed group than that in the left-handed group, whereas the laterality of the inferior parietal lobule had no such significant difference. In both groups, when the difficulty of the task increased, the laterality of the prefrontal cortex, premotor area, and inferior parietal lobule decreased, but the laterality of posterior part of the inferior frontal gyrus increased. CONCLUSIONS: The laterality of the functional brain areas associated with arithmetic calculations can be detected with fMRI. The laterality of the functional areas was related to handedness and task difficulty.

Brain↗
PubMed1992

Distribution and innervation of lateral line organs in the axolotl.

The lateral line system in axolotls consists of three types of receptors and the cranial nerves that innervate them. Superficial neuromasts, which are mechanoreceptors, are distributed in lines on both the head and trunk. Eight cephalic and three trunk lines can be distinguished on the basis of their innervation and differences in the orientation of the major axes of their neuromasts. A combination of histological techniques reveals that five separate pairs of cranial nerves innervate the neuromasts: anterodorsal lateral line nerves innervate cephalic supraorbital and infraorbital lines; anteroventral lateral line nerves innervate cephalic angular, oral, jugal, and preoperculomandibular lines of the cheek and lower jaw; middle and supratemporal lateral line nerves innervate the cephalic postotic lines; and posterior lateral line nerves innervate the trunk lines. In addition to lines of neuromasts, a second class of mechanoreceptive lateral line organs, pit organs, also occur on the head. Pit organs are smaller than neuromasts but are innervated in a manner identical to that of neuromasts: the sensory hair cells of a single pit organ are innervated by two afferent fibers and a single efferent fiber. Although they occur in localized clusters rather than lines, the four distinct pit organ clusters occurring in axolotls are referred to as the anterior, middle, middle cheek, and gular pit lines as they appear to be homologous to the similarly named pit lines in fishes on the basis of their topography and innervation. In addition to neuromasts and pit organs, ampullary organs comprise a third class of lateral line receptors and are restricted to the head. These electroreceptors occur singly or in small clusters adjacent to the neuromast lines and along the base of the external gills. The ampullary organs adjacent to the supraorbital and infraorbital lines are innervated by the anterodorsal lateral line nerves, whereas all other ampullary organs of the head are innervated by the anteroventral lateral line nerves. Thus postotic ampullary organs and neuromasts of the head are innervated by different lateral line nerves. Examination of the sensory ganglia of the lateral line nerves with respect to the ganglia of the other cranial nerves indicates varying levels of fusion. The ganglia of the anterodorsal lateral line and profundal-trigeminal nerves are totally separate throughout their rostrocaudal extent. The ganglia of the anteroventral lateral line and facial nerves form a fused ganglionic complex with the larger pigmented cells of the anteroventral nerve occupying the dorsal portion of the ganglionic complex.(ABSTRACT TRUNCATED AT 400 WORDS)

Ambystoma mexicanum↗
PubMed1993

The octavolateral systems in the stingray, Dasyatis sabina. I. Primary projections of the octaval and lateral line nerves.

The central projections of the electrosensory, mechanosensory, and octaval nerves of the Atlantic stingray were examined by transganglionic transport of horseradish peroxidase. Particular attention was paid to the relation of the projections to cell plates C1 and C2, and to a newly described cell plate, C3. The electroreceptors in the stingray are found in three groups on the dorsal and ventral sides of the body. The electroreceptors are represented topographically on the ipsilateral dorsal nucleus. Those of the rostral part of the head and pectoral fins are represented on the rostroventral part of the nucleus, and those on the caudal part of the head and the pectoral fin on the dorsocaudal part of the nucleus. Mechanosensory lateral line afferents terminate within the ipsilateral intermediate and caudal nuclei, and the lateral granular mass of the vestibulocerebellum. Anterior lateral line afferents also project to the magnocellular octaval nucleus. A topographic representation of the mechanosensory lateral line periphery is present on the intermediate and caudal nuclei. Mechanoreceptors on the trunk are represented laterally and those on the head medially. The terminal field of the anterior lateral line afferents on the intermediate nucleus surrounds cell plates C1 and C2. The anterior lateral line afferents also project to the medial part of the lateral granular mass, whereas the posterior lateral line afferents project to the lateral portion. Sparse projections of anterior lateral line afferents to the periventricular octaval nucleus were also observed. The octaval nerve afferents terminate largely within the octaval column. Octaval nerve projections were also observed to the reticular formation, the periventricular octaval nucleus, the deep cerebellar nucleus, the vestibulocerebellum, particularly the lower lip and medial granular mass, and the intermediate nucleus. A sparse projection to cell plate C3 was found. The relation between cell plates C1 and C2 and the anterior lateral line afferents suggests that these cell plates are related to processing lateral line information. While the relationship between cell plate C3 and the octaval afferents is not strong, the sparse octaval projection C3 receives suggests that it is relaying octaval information.

Afferent Pathways↗
PubMed1985

Somatosensory systems and the milk-ejection reflex in the rat. I. Lesions of the mesencephalic lateral tegmentum disrupt the reflex and damage mesencephalic somatosensory connections.

Bilateral electrolytic lesions and unilateral tracer injections were performed in lactating rats in order to study the participation of the mesencephalic lateral tegmentum in the milk-ejection reflex. The release of oxytocin was detected as a rise in intramammary pressure during each milk ejection. In animals with lesions, the lateral part of the deep grey layers of the superior colliculus, the intercollicular area and the rostromedial portion of the external nucleus of the inferior colliculus were destroyed. The mesencephalic lateral tegmentum of animals in which the milk-ejection reflex was blocked sustained a larger damage than in rats where the frequency of the milk-ejection response was only slowed down. Solutions of True Blue, horseradish peroxidase or horseradish peroxidase coupled to wheat germ agglutinin were injected in the mesencephalic lateral tegmentum of rats with and without lesions. Retrogradely labelled cells were found in several nuclei of the somatosensory pathways: the principal sensory and spinal parts of the trigeminal complex, the cuneate and gracile nuclei, the lateral cervical nucleus and the nucleus proprius of the spinal cord. Labelled cells were also found in the ventral nucleus of the lateral lemniscus, the ventral parabrachial nucleus, the gigantocellular reticular nucleus, the lateral nucleus of the substantia nigra, the prerubral nucleus of the thalamus, the hypothalamic ventromedial nucleus, the zona incerta and in the anterior and lateral hypothalamic areas. Labelled fibres and "terminal-like" labelling were found in the anterior pretectal area, in the thalamic parafascicular nucleus, in the posterior nucleus and the ventroposterior complex, in the zona incerta and in the fields of Forel, but none were observed in the supraoptic or paraventricular nuclei. Injections made in the area of the lateral cervical nucleus and in the cuneate and gracile nuclei labelled fibres and "terminal-like" fields in the external nucleus of the inferior colliculus, the intercollicular area, the deep grey layers of the superior colliculus and in the mesencephalic lateral tegmentum. After injections in the posterior nucleus and ventroposterior complex of the thalamus, retrogradely labelled cells were found in the lateral tegmentum, the intercollicular area and the external nucleus of the inferior colliculus. These results indicate that bilateral lesioning of the mesencephalic lateral tegmentum, which disrupts the milk-ejection response, could damage somatosensory projections originating from the dorsal horn of the spinal cord, the lateral cervical nucleus, the dorsal column nuclei and the sensory and spinal trigeminal nuclei.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed2005

Rapid progression of chondral disease in the lateral compartment of the knee following meniscectomy.

We present 2 cases of severe, rapidly progressive chondral disease in the lateral compartment within 12 months after meniscectomy. In both cases, the lateral compartment was salvaged with simultaneously performed cartilage repair techniques and meniscal transplantation. The first case is of a 16-year-old boy who suffered a complex irreparable posterior horn lateral meniscus tear that was treated with an aggressive partial meniscectomy, and developed a rapid onset of severe lateral compartment symptoms associated with a focal grade IV chondral defect of the lateral femoral condyle within 10 months of his index meniscectomy. The second case is that of an athletic 43-year-old orthopaedic surgeon who suffered a complex lateral meniscus tear that required a near total lateral meniscectomy. Within 5 months of the lateral meniscectomy, he developed severe lateral symptoms with a focal grade IV chondral defect of the lateral femoral condyle. In both cases, the articular cartilage defects were treated with osteochondral grafting at the time of lateral meniscus transplantation with excellent results at 2-year follow-up. These cases highlight the significant need for a heightened the awareness of the relatively increased risk of rapid lateral compartment degeneration following lateral meniscectomy. This, in combination with the appropriate use of cartilage restoration techniques, provides the potential to salvage or prevent rapid onset, unicompartmental degenerative disease, and the ability to reduce symptoms and improve function in these challenging patients.

Adolescent↗
PubMed2003

The lateral crural J-flap repair of nasal valve collapse.

OBJECTIVES: Nasal valve collapse is a common cause of nasal airway obstruction. Although many techniques have been devised to correct both the functional and aesthetic aspects of this problem, none is uniformly successful. I propose that the true locus and solution to the problem lies lateral to the nasal valve angle in the fibroareolar tissue that connects the lateral aspect of the lateral crus to the bony pyriform aperture. Age-related or surgically induced weakening and loosening of these structurally important, fibroareolar connections result in a prolapse of the lateral aspect of the lateral crura away from the pyriform margin and toward the septum with a consequent narrowing of the nasal valve region. A new method of repair is described. METHODS: Bilateral marginal incisions are made following the curvature of the palpated caudal edge of the lower lateral cartilage starting at the dome region medially. The incision is extended laterally until the entire lateralmost aspect of the lateral crus is freed, generating a J-shaped chondrocutaneous flap that is medially and superiorly based. Following this, supraperichondrial dissection of the lateral crus is carried out, exposing the dome region and the upper lateral cartilage. The J-flap is then pulled caudally and laterally, and the excess overlapping tissue is evaluated. Two composite strips of vestibular skin and cartilage are resected: one parallel to the marginal incision and the second at the lateral edge of the J-flap. The flap is transposed and sutured into position, pulling open the nasal valve angle. RESULTS: Preliminary results are presented for 18 patients who underwent 19 lateral crural J-flap repairs of nasal valve collapse. Nine patients underwent concomitant septal, sinus, or turbinate procedures. Two patients underwent unilateral J-flap repair. One patient required revision. Eighty-nine percent of patients reported markedly improved nasal airway patency and elimination of the subjective sensation of inspiratory collapse. Mean time to follow-up was 257 days. There has thus far been no noticeable decrement in benefit over time. CONCLUSION: This new technique for the treatment of nasal valve collapse may offer a simple and effective approach to the problem of nasal valve collapse with minimal morbidity and a high rate of success. The technique is based on a new view of the structural etiology of nasal valve collapse.

Adult↗
PubMedDate not supplied

[Critical assessment of indications for arthroscopic lateral release and medial tightening of the knee joint].

UNLABELLED: Based on the results of a retrospective study of 50 patients with mild lateral tracking and lateral compression of the patella (32 patients) and recurrent patellofemoral dislocation (18 patients), we present the technique, the results, the complications and the indications for the endoscopic lateral retinacular release and medial drawing tight of the capsule. The average age of the patients was 28.8 years (range: 10-53). At time of follow-up (m = 51 months) the patients were examined clinically as well as radiologically. The results were scored according to a score by Crosby and Insall. 73% of the patients with mild lateral tracking and lateral compression (lateral release) were satisfied with the operative results (visual analogue scale), as well as 66.6% of the patients with recurrent patellofemoral dislocation (lateral release and medial drawing tight of the capsule). Only 40% of the patients with patellofemoral arthritis (lateral release) reported about an improvement of this procedure. The score showed significantly good results but didn't raise the differences in between the groups of different indications. 28% of the patients showed an abnormal lateral tracking of the patella in active motion, the passive patella-glide-test (Hughston) raised a patella-hypermobility to the lateral side in 36% of the cases and to the medial side in 76%. X-rays of both knees showed an increased lateral patellofemoral angle of 10.8 degrees and an increased sulcus angle of 144 degrees. There was no progression in osteoarthritis in the operated side of the patellofemoral joint found. Complications revealed in a high number of hemarthrosis right after the operation, in 2 cases an open revision was necessary. CLINICAL RELEVANCE: According to our results patients with patella compression syndrome without patellofemoral arthritis and patients with recurrent luxation or subluxation of the patella are good candidates for endoscopic lateral release and eventually medial drawing tight of the capsule. In a young population the endoscopic lateral release is a relatively simple surgical procedure making an open technique in failed cases possible.

Adolescent↗
PubMed1998

The effects of the lateral position on cardiopulmonary function during laparoscopic urological surgery.

UNLABELLED: Laparoscopic urological surgery is usually performed transperitoneally with retroperitoneal insufflation of carbon dioxide (CO2) in the lateral position. We studied whether a difference in the side of lateral position affected hemodynamic and pulmonary functions during pneumoperitoneum. Fifteen patients (eight in the right and seven in the left lateral position) undergoing elective laparoscopic urological surgery were studied under general anesthesia. Hemodynamic variables and blood gas data were recorded. Before insufflation, mean arterial pressure (MAP), mean pulmonary arterial pressure (MPAP), central venous pressure (CVP), and pulmonary capillary wedge pressure (PCWP) in the right lateral position were higher than those in the left lateral position. Pneumoperitoneum increased MAP, MPAP, CVP, PCWP, and cardiac index but decreased systemic vascular resistance in the right lateral position. Similar changes occurred during pneumoperitoneum in the left lateral position, but the changes were less than those in the right lateral position. The respiratory index (PaO2/PAO2), intrapulmonary shunt, and SpO2 did not change during pneumoperitoneum in either lateral position. Changing the side of the lateral position affected hemodynamic function but did not affect pulmonary oxygenation during pneumoperitoneum. IMPLICATIONS: The right and left lateral positions produced different hemodynamic changes during laparoscopic urological surgery. The increases in preload and cardiac index and the decrease in systemic vascular resistance were greater in the right than in the left lateral position. Respiratory changes were not affected differently between the right and left lateral positions.

Anesthesia, General↗
PubMed2005

The effect of lateral cortex disruption and repair on the stability of the medial opening wedge high tibial osteotomy.

BACKGROUND: Medial opening wedge high tibial osteotomy is gaining popularity as a treatment option for medial compartment degenerative disease in the young, active patient. One of the potential technical pitfalls of this procedure is inadvertent disruption of the lateral tibial cortex during distraction at the osteotomy site. PURPOSE: (1) To investigate the effect of lateral cortex disruption on stability during medial opening wedge high tibial osteotomy and (2) to evaluate 3 different methods of repair of the disrupted lateral cortex. STUDY DESIGN: Controlled laboratory study. METHODS: A total of 50 validated replicate tibias were evaluated in a medial opening wedge high tibial osteotomy model. Specimens were divided into 5 groups: (1) control, or intact lateral cortex (n = 10); (2) disrupted lateral cortex (n = 10); (3) lateral cortex repaired with 1 staple (n = 10); (4) lateral cortex repaired with 2 staples (n = 10); and (5) lateral cortex repaired with a periarticular plate and screws (n = 10). Specimens were placed in compression and torsion under physiologic loads, and stiffness and micromotion were calculated. RESULTS: Disruption of the lateral cortex resulted in a 58% reduction in axial stiffness and a 68% reduction in torsional stiffness compared to control specimens (P < .05). Disruption of the lateral cortex also resulted in increased micromotion at the osteotomy site. All 3 methods of repair of the lateral cortex restored stiffness and micromotion values to those of the control group (P < .05). CONCLUSIONS: Instability at the osteotomy site may contribute to the high rate of delayed union or nonunion associated with medial opening wedge high tibial osteotomy. Repair of the lateral tibial cortex by each of these techniques restored stability to the osteotomy site in this replicate tibia model and might be effective in clinical use. However, more studies are needed to further explore the relationship between lateral cortex disruption and patient outcomes in the clinical setting before definitive conclusions can be drawn.

Biomechanical Phenomena↗
PubMed2003

Differential features of metabolic abnormalities between medial and lateral temporal lobe epilepsy: quantitative analysis of (18)F-FDG PET using SPM.

UNLABELLED: Because limited resection could yield an equally good surgical outcome as standard anterior resection in temporal lobe epilepsy (TLE), the differentiation of medial from lateral TLE is important. We tried to find the differential features in metabolic abnormalities between medial and lateral TLE groups using quantitative analysis including statistical parametric mapping (SPM). METHODS: We examined 113 (18)F-FDG PET scans of TLE patients who had surgically and pathologically proven lesions and a good surgical outcome (78 medial TLE, 35 lateral TLE). Each scan was compared with those of 22 healthy control subjects to detect hypometabolic regions using a t test of the SPM method and interhemispheric asymmetry using 2-group, 2-condition analysis on SPM. Group analysis was performed between medial and lateral TLE using mirrored PET images. The sensitivity was defined as the detection rate of hypometabolism in the ipsilateral temporal lobes, and the specificity was defined as the nondetection rate in the contralateral lobes. The extent of the hypometabolism was calculated as the number of significant voxels, and the severity was calculated by the asymmetry index (ASI), in the medial or lateral temporal lobes on Statistical Probabilistic Anatomical Map template images. RESULTS: The hypometabolism in the temporal lobes was detected ipsilateral to the seizure focus in 76% of the TLE patients (76% in medial TLE, 77% in lateral TLE) but on the contralateral temporal lobes in 32% of the patients. After considering interhemispheric temporal asymmetry, the sensitivity was found to be 89%, and the specificity was 91% without differences between the medial and lateral TLE groups. In both medial and the lateral TLE, the hypometabolism was more prominent in the lateral cortical structures than in the medial structures. The hypometabolism in the medial temporal structures was found less frequently in the lateral TLE group, and the extent of the hypometabolism was significantly larger in the medial TLE group. ASIs of the medial temporal structure and superior temporal gyrus of lateral temporal structure were significantly higher in the medial TLE. CONCLUSION: SPM analysis of (18)F-FDG PET in TLE patients could localize accurately the seizure focus and helped in the discrimination of the medial TLE from the lateral TLE. We suggest the lateral TLE, rather than the medial TLE, should be considered when glucose metabolism is relatively preserved in the medial temporal structures.

Adult↗
PubMed2003

[The relation and evaluation of the vertebral artery and the nerve root to posterior lateral mass screw fixation].

OBJECTIVE: To determine the location of the vertebral artery foramens from C(3) to C(6) and their relationship to the point 1 mm medial to the center of the lateral mass and to identify the value of oblique radiograph for cervical lateral mass screw trajectory by a cadaveric study. METHODS: (1) Twenty-eight cervical specimens (C(3)-C(7)) of human cadavers aged from 28 to 79 years were analysed. The transverse radiographs of C(3)-C(6) vertebrae were taken and the angle between the parasagittal plane and the line connecting the point of the lateral mass with the lateral limit of the transverse process foramen of C(3)-C(6) were measured. (2) The K-wires were drilled into lateral mass of C(3)-C(6) starting 1 mm medial to the center of the lateral mass and exiting by the juncture between the transverse process and the facet in ten specimens. Four wire placements under direct visualization, including placement of the wire tip staying the ventral cortex and 2, 4, 6 mm over-penetration of the ventral cortex of lateral mass, were performed separately on each specimen. After each placement, radiographs were taken on 45 degrees oblique left and 45 degrees oblique right views. Each intervertebral foramen on the oblique radiographs was divided into two parts: superior and inferior parts. The former is the true intervertebral foramen, while the latter is the intertransverse foramen on the gross specimen. The number of wire tips in each part was quantified for each placement. All results on the radiographs were compared with those on the gross anatomy. RESULTS: (1) The angles between the parasagittal plane and the line connecting the posterior starting point of the lateral mass with the lateral limit of the transverse foramen (C(3)-C(6)) were lateral to the sagittal plane, ranging from 5 degrees to 12 degrees. Among the vertebrae, there were no statistically significant difference (P > 0.05). (2) 15% of the wires without over-penetration and 41.3% with 2 mm over-penetration were found in the inferior parts of the intervertebral foramen in oblique views, while the wires were not noted in the intervertebral foramen by gross anatomy. with 4 mm over-penetration of the ventral cortex, 35% and 65% of wires were noted in the superior and inferior parts of the intervertebral foramen respectively, while only 28.8% of wires were found in the inferior part approximating the nerve roots in gross specimens. With 6 mm over-penetration, the number in the intervertebral foramen were 63.8% superiorly and 36.2% inferiorly on the oblique radiographs while all the tips were at the inferior part (intertransverse foramens) in gross specimens. The tip of wire crossed the line connecting the posterior borders of the intervertebral foramens in oblique radiographs when it penetrated the ventral cortex of lateral mass 4 mm or more. CONCLUSIONS: (1) There is no risk of damaging the vertebral artery if a screw is directed more than 15 degrees lateral to the sagittal plane at C(3 approximately 6) starting 1 mm medial to the center of the lateral mass. (2) Ideal screw tip position on oblique radiograph may not cross the line connecting the posterior borders of the intervertebral foramen on radiograph. If the screw tip is noted in the superior part of intervertebral foramen on the oblique radiograph, the screw may be identified as dangerous.

Adult↗
PubMedDate not supplied

Ethanol enhances medial amygdaloid induced inhibition of predatory attack behaviour in the cat: role of GABAA receptors in the lateral hypothalamus.

The present study tested the hypothesis that the suppressive effects of ethanol upon predatory attack behaviour in the cat involve a pathway from the medial amygdala to the lateral hypothalamus, and that these suppressive effects are mediated by gamma-aminobutyric acid (GABAA) receptors located in the lateral hypothalamus. Cannula electrodes were implanted into the lateral hypothalamus for elicitation of predatory attack behaviour and for microinjections of the GABAA receptor antagonist, bicuculline. Monopolar stimulating electrodes were implanted into the medial amygdala from which subseizure levels of electrical stimulation suppressed predatory attack behaviour. In the first phase of the study, we compared response latencies for predatory attack behaviour following single stimulation of the lateral hypothalamus alone with those following paired trials of dual stimulation of the medial amygdala plus lateral hypothalamus. Dual stimulation significantly suppressed predatory attack. In the second phase of the study, peripheral ethanol administration (in doses of 0.01, 0.5 and 1.0 g/kg, i.p.) enhanced the suppressive effects of medial amygdaloid stimulation in a dose- and time-dependent manner in which peak effects were obtained 60 min post-injection. In the third phase of the study, bicuculline (0.15 nmol) was microinjected into the lateral hypothalamus both prior to and following paired trials of dual stimulation. Drug infusion blocked the suppressive effects of medial amygdaloid stimulation upon predatory attack behaviour elicited from the lateral hypothalamus, indicating the importance of GABAA receptors in mediating this suppression. In the fourth phase of the study, bicuculline, microinjected into the lateral hypothalamus at the time when ethanol's effects were maximal (i.e. 60-80 min post-ethanol administration), totally blocked the suppressive effects of medial amygdaloid stimulation as well as the enhancing effects of ethanol upon medial amygdaloid suppression of this form of aggressive behaviour. In the last phase of the study, bicuculline (0.15 nmol) infusion into the lateral hypothalamus significantly reduced the suppressive effects of ethanol (1.0 g/kg, i.p.) upon predatory attack behaviour elicited from the lateral hypothalamus. These results support the hypothesis that ethanol's suppressive effects upon predatory attack behaviour in the cat are mediated, at least in part, by GABAA receptors in the lateral hypothalamus. The present and recent findings in our laboratory support the view that GABAA receptors in the lateral hypothalamus are activated, in turn, by a GABAergic pathway which arises from the medial hypothalamus whose neurons receive inputs from the medial amygdala.

Amygdala↗
PubMed2006

The role of the lateral line and vision on body kinematics and hydrodynamic preference of rainbow trout in turbulent flow.

The ability to detect water flow using the hair cells of the lateral line system is a unique feature found in anamniotic aquatic vertebrates. Fishes use their lateral line to locate prey, escape from predators and form cohesive schooling patterns. Despite the prevalence of complex flows in nature, almost nothing is known about the function of the lateral line and its relationship to other sensory modalities for freely swimming fishes in turbulent flows. Past studies indicate that under certain conditions the lateral line is not needed to swim steadily in uniform flow. This paper examines how the lateral line and vision affect body kinematics and hydrodynamic habitat selection of rainbow trout (Oncorhynchus mykiss) exposed to vortices generated behind a cylinder. Trout Kármán gaiting (i.e. exploiting vortices to hold station in a vortex street) with a pharmacologically blocked lateral line display altered kinematics; body wavelength and wave speed increase compared to control animals. When visual cues are withheld by performing experiments in the dark, almost all Kármán gait kinematics measured for fish with and without a functional lateral line are the same. The lateral line, rather than vision, plays a larger role in affecting body kinematics when trout hold station in a vortex street. Trout show a preference to Kármán gait in the light but not in the dark, which may be attributed to physiological state rather than hydrodynamic or sensorimotor reasons. In the dark, trout both with and without a functional lateral line hold station near the downstream suction region of the cylinder wake (i.e. entraining) and avoid the vortex street. Vision therefore plays a larger role in the preference to associate with a turbulent vortex street. Trout in the light with a blocked lateral line show individual variation in their preference to Kármán gait or entrain. In the dark, entraining trout with an intact lateral line will alternate between right and left sides of the cylinder throughout the experiment, showing an ability to explore their environment. By contrast, when the lateral line is blocked these fish display a strong fidelity to one side of the cylinder and are not inclined to explore other regions of the flow tank. Both entraining and Kármán gaiting probably represent energetically favorable strategies for holding station relative to the earth frame of reference in fast flows. The ability to decipher how organisms collect and process sensory input from their environment has great potential in revealing the mechanistic basis of how locomotor behaviors are produced as well as how habitat selection is modulated.

Animals↗
PubMed1999

Paraxial and lateral plate influences on reinitiation of wing development in chicken embryos.

Stephens et al. ([1993] Dev. Dynam. 197:157-168) hypothesized that the chick embryo wing territory is not an equipotential system. They proposed that following extirpation of the wing territory, limb formation is reinitiated, stimulated by more paraxial tissues. It was the purpose of this study to test this hypothesis. Four sets of procedures were undertaken in stage 11-12 chick embryos: 1) the wing territory lateral plate was removed (negative controls); 2) medial (between the central axis and somites), lateral (between the mesonephros and lateral plate), and intermediate (between the somites and mesonephros) foil barriers were placed adjacent to the wing territory (positive controls); 3) barriers were placed as above, with the removal of the lateral plate (experimental); and 4) barriers were placed lateral to the area of lateral plate extirpation (experimental). Normal limbs developed in 89% of the embryos without foil barriers with the lateral plate removed. In 93% of the embryos that contained medial barriers, normal wings developed whether or not the limb territory was extirpated, and in 100% of the embryos with intermediate or lateral barriers, with or without extirpation, deficient limbs occurred. When foil barriers were placed lateral to the wound, 87% of the chick wings were either reduced or absent. Closure of the wound following extirpation appeared to progress from lateral to medial. The data from this study appear to support the hypothesis that the limb territory is not equipotential but is reformed from cells closing the wound from lateral to medial, and is reinitiated from paraxial tissues (medial to lateral) following wound healing.

Animals↗
PubMed1996

Ductal heterogeneity in rat dorsal-lateral prostate.

Given the lobar complexity of the rat prostate at the morphological level, differences in secretory protein expression were investigated in individual prostatic ducts that constitute the subdivisions of the dorsal-lateral prostate, ie., the dorsal prostate, lateral prostate type 1 and lateral prostate type 2. For this purpose, individual prostatic ducts were microdissected from these prostatic lobes, photographed, and secretions subsequently collected from individual prostatic ducts and analyzed by Western blot for the expression of DP-1 and probasin, two major proteins expressed in rat the dorsal-lateral prostate. Many individual glands constituting the dorsal prostate, lateral prostate type 1 and lateral prostate type 2 co-express DP-1 and probasin, but at vastly different levels. DP-1 is a major secretory protein of the dorsal prostate and lateral prostate type 1, while probasin is the major secretory protein of the lateral prostate type 2. A small percentage of individual ducts of the dorsal prostate, lateral prostate type 1 and lateral prostate type 2 express either DP-1 or probasin. However, most of the individual prostatic ducts constituting the dorsal prostate and lateral prostate type 1 express DP-1 at high levels and probasin at low levels. Conversely, most of the individual prostatic glands that constitute the lateral prostate type 2 express probasin at high levels and DP-1 at low levels. This study emphasizes the morphological and functional heterogeneity within the prostate gland.

Androgen-Binding Protein↗
PubMed1994

Projections from the lateral and interposed cerebellar nuclei to the thalamus of the rat: a light and electron microscopic study using single and double anterograde labelling.

The lateral and interposed cerebellar nuclei may have different functions in the control of movement. Efferent fibres from both nuclei project predominantly to areas of the thalamus, which in turn project to the motor cortex. In this study, single and double anterograde-tracing techniques have been used to examine and compare the pathways from the lateral and interposed nuclei to the thalamus in the rat by using both light and electron microscopy to look for evidence of organisational or structural features that may underlie the proposed functional differences between these nuclei. Terminals from the lateral nucleus were found to be located most medially in the thalamus, predominantly in the ventral lateral nucleus and the rostral pole of the posterior nuclear group. Terminals from the posterior interposed nucleus were located slightly rostral and lateral to those from the lateral nucleus, mainly around the border between the ventral lateral nucleus and the ventral posterior medial nucleus. Terminals from the anterior interposed nucleus were located slightly rostral and lateral to those from the posterior interposed nucleus, predominantly in the rostral pole of the ventral posterior lateral nucleus. Terminals from the lateral and interposed nuclei were also found in double anterograde-tracing experiments to be nonoverlapping in the regions between these main areas of termination. The structure of terminals from the lateral and interposed nuclei, however, as well as their synaptic relationship with thalamic neurones, were found to be similar. The terminals are large and form synapses with proximal dendrites of thalamic neurones. They contained round vesicles and formed multiple synaptic contacts with dendritic shafts, as well as dendritic spines. The findings indicate that information from the lateral and interposed nuclei is processed in separate regions of the thalamus but that the mode of synaptic transfer to thalamic neurones is likely to be similar for the two projections.

Animals↗
PubMed2000

Lateral node dissection and total mesorectal excision for rectal cancer.

PURPOSE: Although the existence of lateral lymphatic drainage of the rectum has been verified anatomically, the clinical importance of it has not yet been fully investigated. The lack of a definition of lateral lymphatic flow makes it difficult to analyze and compare data. The aim of this study was to define the concept of lateral lymphatic drainage and explore its relationship to total mesorectal excision and to disclose the incidence and efficacy of dissection of lateral node involvement. METHODS: Review of anatomic and clinical research on lateral lymphatic flow was made to create a definition of lateral lymphatic flow. Based on this review, a three-space dissection was designed and applied. A retrospective analysis was made of 764 patients with rectal cancer treated by a curative three-space dissection operation during 20 years starting in 1975 at Cancer Institute Hospital. RESULTS: Lateral lymphatic flow passes from the lower rectum and through the lateral ligament laterally beyond the mesorectum. It then ascends along the internal iliac artery and, in addition, inside the obturator space. Sixty-six cases proved to have lateral node involvement, which comprised 8.6 percent of all rectal cancer and 16.4 percent of low-lying (lower margin below 5 cm above the dentate line) rectal cancer cases. The five-year survival rate of these 66 cases was 42.4 percent. There were 16 cases that had a solo lateral node involvement. CONCLUSION: Lateral lymphatic flow from low-lying rectal cancer passes outside the boundaries of total mesorectal excision but within the range of curative surgery by three-space dissection.

Humans↗