Biomedical subjects

H Namba

Publications and source records attributed to H Namba.

At least 127 records · Page 7Linked to original sources

PubMed1995

A single missense mutation in codon 918 of the RET proto-oncogene in sporadic medullary thyroid carcinomas.

The RET proto-oncogene is expressed in human medullary thyroid carcinoma and pheochromocytoma. Recently germline mutations of the RET proto-oncogene were reported in four syndromes (MEN 2A, MEN 2B, familial medullary thyroid carcinoma and Hirschprung's disease) and somatic mutation was also found in sporadic medullary thyroid carcinoma. To determine the incidence of RET mutations in medullary thyroid carcinoma in Japan, we investigated 14 medullary thyroid carcinomas (comprising 1 case of MEN 2A, 1 case of MEN 2B, 2 cases of familial medullary thyroid carcinoma and 10 cases of sporadic). Tumors from all cases were screened by PCR-SSCP on exons 10 and 11. DNA sequencing on these exons was performed for the hereditary medullary thyroid carcinoma cases. The PCR products of exon 16 from tumor DNA were analyzed by means of Fok1 restriction enzyme digestion analysis and mutations confirmed by DNA sequencing. We found no structural abnormalities in either exon 10 or exon 11 in any of the cases examined, but in four of 10 sporadic cases we detected a common point mutation at codon 918 (ATG to ACG) in exon 16, where methionine was replaced with threonine. Our results support the theory that a point mutation of exon 16 of the RET proto-oncogene may be related to the oncogenesis of sporadic medullary thyroid carcinomas. However, further studies on the entire RET proto-oncogene are needed to clarify the relationship between its expression and thyroid tumorigenesis.

Base Sequence↗

PubMed1995

Establishment and characterization of a malignant epithelioid hemangioendothelioma from mouse thyroid tumor.

A mouse epithelioid hemangioendothelioma (mEHE) cell line, passagable in vivo without TSH stimulation, was established from a thyroid tumor. Before establishment of the cell line, the primary thyroid tumor which was co-transplanted with a TSH-producing pituitary adenoma showed signs of hyperplasia and then transformed during several in vivo transplantable passages. The cell line which was established from an in vitro culture, was deficient in thyroid-specific differentiation function and had characteristics of endothelial cell origin such as vascular cavity formation and factor VIII expression. The cell growth of mEHE/CH1-5 cell lines was independent of TSH but was inhibited by c-AMP and vitamin D3. c-Myc proto-oncogene expression was also suppressed by vitamin D3 treatment. Both serum depletion and heparin treatment induced morphological changes in mEHE/CH 5 from an epithelial cell-like to an endothelial cell-like shape. Immunohistochemical analysis showed that epithelial membrane antigen expression was decreased and factor VIII expression was increased in relation to the morphological changes. In a further in vivo transplantation experiment, the histology of the mEHE/CH5 cell tumor had an angiosarcoma-like structure. These results indicate that this cell line established from a thyroid tumor possesses both epithelial and endothelial characteristics. The mEHE/CH5 cells might provide a good model for analyzing thyroid tumorigenesis and allow functional characterization of endothelial cells.

Animals↗

PubMed1995

Intra-arterial ACNU and cisplatin chemotherapy for the treatment of glioblastoma multiforme.

Intra-arterial (IA) chemotherapy has achieved no obvious clinical superiority as a treatment for glioblastoma multiforme despite the many theoretical advantages. The clinical courses of 38 patients who underwent surgery and radiotherapy with IA 1-(4-amino-2-methyl-5-pyrimidinyl)-methyl-3-(2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) and cisplatin were reviewed. Tumor regrowth was evaluated by comparison of contrast-enhanced areas on computed tomographic scans. The initial response rate was 19 of 32 patients evaluated, and the median survival time (MST) for all 38 patients was 53 weeks. Local recurrence was observed in 20 patients, and distant recurrence (areas more than 3 cm from the original tumor margin) was observed in 15 patients. The MST was 59 weeks for patients without distant recurrence, and 42 weeks for patients with distant recurrence (statistically not significant). Adjuvant IA ACNU and cisplatin chemotherapy did not improve the survival time. An important clinical feature was the high incidence of distant recurrence, in contrast to experience with other conventional therapy regimens. Distant recurrence, without extended survival, may suggest insufficient control of tumor regrowth.

Adolescent↗

PubMed1995

Simplified PET quantitation of myocardial glucose utilization.

UNLABELLED: The purpose of this study was to validate experimentally a simple method to quantify tissue glucose utilization with the brain reference index (BRI) using 14C-deoxyglucose and assess its clinical feasibility for myocardial PET. METHODS: To validate the BRI method, glucose utilization in myocardial and skeletal muscle was studied in rats with 14C-deoxyglucose after increasing doses of oral glucose loading. To assess clinical feasibility of the method, the BRI was applied to nine patients undergoing myocardial PET and compared to rMGU measured by the deoxyglucose model of Sokoloff et al. and by Patlak graphical analysis. The normal range of myocardial FDG uptake expressed as the BRI was estimated with four normal volunteers. RESULTS: In skeletal muscle, a dose-dependent increase of glucose utilization was observed during oral glucose loading with doses up to 4 mg/g. In the myocardium, glucose utilization increased with a glucose loading dose of up to 1 mg/g without increasing further at greater glucose doses. Ratios of maximal glucose utilization in glucose-loaded rats to 19-hr fasted rats (controls), expressed as the BRI for left and right ventricular myocardium and skeletal muscle were 4.16, 3.74 and 7.39, respectively. Glucose utilization of right ventricular myocardium was approximately 70% of left ventricular myocardium for all glucose-loaded conditions. For patients, the BRI correlated with rMGU; four of these patients had a constant plasma glucose concentration. CONCLUSION: Myocardial BRI is a sensitive indicator of rMGU that does not require dynamic data acquisition or constant plasma glucose concentrations.

Animals↗

PubMed1995

Parathyroid hormone-related peptide expression in endocrine tumors.

Parathyroid hormone-related peptide (PTHrP) expression is associated with the histological type in pituitary tumor, but not in thyroid carcinoma. However invasive and metastatic tumors showed intense PTHrP staining in both pituitary and thyroid tumors. Analysis of the established metastatic rat pituitary tumor cell line showed that PTHrP plays a crucial role in in vivo cell proliferation closely related to worsening of malignant transformation and neovascularization in a paracrine fashion.

Animals↗

PubMed1995

Automated measurement of urinary iodine with use of ultraviolet irradiation.

We have modified an automated measurement system of urinary iodine (UI) and established a sensitive UI assay system by using ultraviolet (UV) digestion. The automated system is sensitive enough to detect concentrations of UI < 0.78 mumol/L (< 10 micrograms/dL) in a small volume of urine (500 microL). Sample throughput is > 30/h, including a water washing. The within-assay imprecision (CV) was < or = 10% in the UI range of 0.10-3.00 mumol/L; the between-assay CV was usually < or = 15% in the same range. Analytical recovery of iodine added to urine samples was consistently > 90%. The theoretical values were recovered when UV irradiation was used but not in its absence. High (supraphysiological) doses of thiocyanate or ascorbic acid, which are major interfering substances to the ceric-arsenious acid reaction, did not interfere with this system. The correlation between UI determined by this method and by the acid digestion method was linear (r = 0.994). For samples containing iodine at < 1.00 mumol/L, the correlation between values by both methods was still significant (r = 0.937). UI in an iodine-deficient area in Ukraine, measured by this system, ranged from 0.06 to 1.83 mumol/L (median 0.44 mumol/L, n = 95), significantly lower than in Japan (range 0.23-50.70 mumol/L, median 4.70 mumol/L, n = 84) and consistent with mild iodine deficiency. This modified automated assay system, therefore, is useful and applicable for screening UI in inhabitants of iodine-deficient areas.

Arsenates↗

PubMed1995

[A study on thallium-201 SPECT in brain metastases of lung cancer: with special reference to tumor size and tumor to normal brain thallium uptake ratio].

Thallium-201 brain SPECT was performed on 20 patients with brain metastases of lung cancer using a three-head rotating gamma camera and the effect of tumor size on tumor detectability and tumor to normal brain thallium uptake ratio (T/N ratio) was studied. Among 71 metastatic lesions, only 9 (22.5%) of 40 lesions of 13 mm diameter or below and 31 (100%) of 31 lesions of 14 mm diameter or above could be detected in this study. There was a significant correlation between T/N ratio and tumor size (r = 0.75, p < 0.001). The greater the metastatic lesion, the higher the T/N ratio. Even among the tumors in a single patient with multiple brain metastases, there was a significant linear correlation between tumor size and T/N ratio (r = 0.96, p < 0.01). In this patient, T/N ratio varied by the tumor size and these differences in T/N ratios were thought to be based on the partial volume effect. However, T/N.d which was a parameter corrected by tumor diameter (d) showed a constant value regardless of tumor size. The present results showed that T/N ratio, which was usually believed to quantitate the malignancy grade of brain tumor, was affected by tumor size and that more accurate parameter could be obtained by the correction of T/N ratio by tumor size.

Adenocarcinoma↗

PubMed1995

[Surgical repair of valvular diseases in patients over 75 years of age].

From January 1985 through August 1993, 41 patients older than 70 years underwent valvular surgery. In them, 10 patients were older than 75 years old. We evaluated those operative results. First, we classified them into 3 groups; Group A: over 75 y.o. (10 cases), Group B: 70-74 y.o. (31 cases) and Group C: 60-69 y.o. (39 cases, from January 1992 through August 1993). Surgical deaths were 1 case in Group A, and 1 in Group B. Distant deaths were 1 case in Group B, and 2 in Group C. Preoperative cardiac catheterization data showed the progression of cardiac failure in proportion to aging. But postoperative data showed no difference among 3 groups, and the condition was reversible. NYHA classification and cardiothoracic ratio (CTR) showed the same results. In summary, in valvular diseases in patients over 75 years of age, the progression of the condition was recognized but it was reversible. So we conclude that the surgical repair of no influence of age is necessary.

Aged↗

PubMed1994

In vivo measurement of acetylcholinesterase activity in the brain with a radioactive acetylcholine analog.

A novel method for visualization of brain acetylcholinesterase (AChE) in vivo has been developed. Following intravenous administration of a radiolabelled acetylcholine analog, N-methyl-3-piperidyl acetate, there was very good agreement between the distribution of radioactivity and AChE activity in the brain of rat and monkey. The method would be applicable for in vivo studies of human brain AChE activity in disorders of central cholinergic systems such as Alzheimer's disease.

Acetylcholine↗

PubMed1994

Coronary atherosclerotic smooth muscle cells overexpress human parathyroid hormone-related peptides.

Parathyroid hormone-related peptide (PTHrP) was originally characterized as a tumor product responsible for hypercalcemia of malignancy and was subsequently found to be produced in many normal tissues. PTHrP is now suggested to play a critical role in the local modulation of vascular smooth muscle function. To elucidate the involvement of PTHrP in coronary atherosclerosis, we immunohistochemically examined coronary arteries obtained from 76 patients with various grades of atherosclerosis and compared the correlation between PTHrP staining and the percent stenosis. Smooth muscle cells at sites of coronary atherosclerosis overexpressed PTHrP, while cells from normal coronary arteries did not. The in situ hybridization using PTHrP riboprobe has also proven the overexpression of PTHrPmRNA in the affected lesions following atherectomy. The intensity of PTHrP expression by smooth muscle cells was significantly correlated with the degree of coronary artery stenosis. Coronary arterial PTHrP overexpression is closely related to the severity and/or progression of coronary atherosclerosis.

Adult↗

PubMed1994

Effect of transforming growth factor-beta on the insulin-like growth factor-I autocrine/paracrine axis in cultured rat articular chondrocytes.

Transforming growth factor-beta (TGF-beta) and insulin-like growth factor-I (IGF-I) are essential anabolic factors in articular cartilage. In this study, we concentrated on the elucidation of TGF-beta interaction with IGF-I on cell growth and differentiation in monolayer articular chondrocytes obtained from 5-week-old rats. TGF-beta (1 ng/ml) and IGF-I (25 ng/ml) stimulated DNA synthesis about 6.5- and 2.1-fold over control values, respectively. When TGF-beta and IGF-I were added in combination, DNA synthesis was enhanced about 10.4-fold, indicating that the two peptides act in synergism. This synergistic action was also present in the expression of aggrecan mRNA. To study the mechanism of synergistic action, the effect of TGF-beta on the IGF-I autocrine/paracrine axis was investigated. Administration of increasing concentrations of TGF-beta (0.1-10 ng/ml) resulted in a dose-dependent decrease in medium IGF-I concentration that was reflected by decreased levels of IGF-I mRNA. TGF-beta also inhibited the production of a 41-kDa IGF-binding protein into the culture medium. Pretreatment with TGF-beta (1 ng/ml) for 12 h increased the binding of [125I]IGF-I to 140% of control by increasing the number of receptors without changes of affinity. Immunoprecipitation against phosphorylated tyrosine indicated that IGF-I-dependent autophosphorylation of IGF-I receptor beta-subunit was inhibited by simultaneous TGF-beta stimulation. These observations demonstrate that TGF-beta acts synergistically with IGF-I and regulates the IGF-I autocrine/paracrine axis via a complex regulatory mechanism with decreased production of IGF-I and IGFBPs and dephosphorylation of IGF-I receptor, whereas there is an apparent up-regulation of the binding of [125I]IGF-I.

Aggrecans↗

PubMed1994

A simple method for measuring glucose utilization of insulin-sensitive tissues by using the brain as a reference.

A simple method, without measurement of the plasma input function, to obtain semiquantitative values of glucose utilization in tissues other than the brain with radioactive deoxyglucose is reported. The brain, in which glucose utilization is essentially insensitive to plasma glucose and insulin concentrations, was used as an internal reference. The effects of graded doses of oral glucose loading (0.5, 1 and 2 mg/g body weight) on insulin-sensitive tissues (heart, muscle and fat tissue) were studied in the rat. By using the brain-reference method, dose-dependent increases in glucose utilization were clearly shown in all the insulin-sensitive tissues examined. The method seems to be of value for measurement of glucose utilization using radioactive deoxyglucose and positron emission tomography in the heart or other insulin-sensitive tissues, especially during glucose loading.

Adipose Tissue↗

PubMed1994

Growth hormone directly and indirectly stimulates articular chondrocyte cell growth.

Although growth hormone (GH) is known to regulate cartilage growth and differentiation during development, it is still unclear whether the cell growth of articular chondrocytes is stimulated directly by GH or mediated by GH-induced insulin-like growth factor-I (IGF-I). In the present study, we focused on whether GH directly or indirectly stimulates articular chondrocyte proliferation. Monolayer articular chondrocytes from 5-week-old male Sprague-Dawley rats were cultured in Ham's F-12/Dulbecco's modified essential medium supplemented with 10% fetal bovine serum. Stimulation of DNA synthesis by GH was dose-dependent between 0.1 and 1 microg/ml, and the maximum active concentration of GH was 500 ng/ml, which induced a 3.5-fold increase over control values. Anti-IGF-I antiserum neutralized about 80% of GH-induced DNA synthesis. GH stimulated the secretion of IGF-I into the conditioned medium in a dose-responsive manner. To determine whether GH stimulated DNA synthesis directly, we investigated the time-course changes in mRNA expression of IGF-I and the proto-oncogene c-myc. Induction of IGF-I mRNA occurred at 4 h, and reached a maximum level at 12 h, whereas the expression of c-myc mRNA was induced within 4 h, and continued to increase until 72 h after GH treatment. Furthermore, administration of cycloheximide, an inhibitor of protein synthesis, resulted in the superinduction of both IGF-I and c-myc mRNAs. These results suggest that early induction of c-myc is due to a direct stimulatory effect of GH, and that long-term induction of c-myc was attributable to an indirect effect of GH in which GH-induced secondary proliferative factors may act in an autocrine/paracrine manner. The superinduction of c-myc gene by cycloheximide also indicates that fresh protein synthesis of an intermediate protein was not required for GH-induced c-myc expression. Western ligand blot analysis of IGF-binding proteins revealed that cultured rat articular chondrocytes produced a predominant 41 kDa and a faint 32 kDa form, and that GH significantly stimulated the secretion of the 41 kDa form without affecting expression of the 32 kDa form. Furthermore, a specific IGF-I binding study suggested that the increase in DNA synthesis induced by GH was not associated with changes in affinity or in the number of IGF-I binding sites. These results support the conclusion that the stimulatory effect of GH was mainly mediated by GH-induced IGF-I production in monolayer rat articular chondrocytes. However, it is likely that GH may also have a direct stimulatory effect by inducing c-myc proto-oncogene expression.

Animals↗

PubMed1994

Clonidine and lidocaine inhibition of isoflurane-induced tachycardia in humans.

BACKGROUND: A rapid increase in isoflurane concentration can induce tachycardia and hypertension and increase plasma catecholamine concentrations. To investigate a possible mechanism, we measured hemodynamic responses to isoflurane administered via mask; we also administered clonidine for premedication, lidocaine topically to the nasal mucosa, or lidocaine intravenously to evaluate the effect of these drugs on the hemodynamic responses. METHODS: Forty ASA physical status 1 patients (aged 20-30 yr) scheduled for elective oral surgery participated in the study. Thirty patients were randomly allocated to one of three groups: a control group, a group receiving 3-4 micrograms.kg-1 of oral clonidine for premedication, and a group receiving 2 ml of 4% lidocaine spray to the nasal mucosa. Ten patients were assigned nonrandomly to a group receiving intravenous lidocaine continuously (0.4 mg.kg-1 bolus followed by 30 micrograms.kg-1.min-1) after the initial randomized experiments were done to test whether systemic lidocaine blunts the responses to inhaled isoflurane. Anesthesia was induced with thiamylal, after which inhalation of 1% isoflurane in 100% oxygen via mask was begun. The inspired concentration of isoflurane was increased by 1% every 5 min to a maximum of 4%. During normocapnia and without surgical stimulation, heart rate and systolic blood pressure were measured every minute for 20 min before and during isoflurane inhalation. Plasma catecholamine concentrations were measured before and at each isoflurane concentration. RESULTS: In the control and intravenous lidocaine groups, an increase in isoflurane concentration from 2% to 3% significantly increased systolic blood pressure (peak changes of 16 +/- 5 and 15 +/- 6 mmHg, respectively) and heart rate (peak changes of 23 +/- 3 and 13 +/- 4 beats.min-1, respectively). A change in concentration to 4%, however, did not significantly alter hemodynamics. Blood pressure and heart rate responses to a change to 3% isoflurane were significantly blunted in the groups receiving clonidine (peak changes of 4 +/- 4 mmHg and 8 +/- 3 beats.min-1, respectively) or nasal lidocaine (peak changes of 2 +/- 1 mmHg and 4 +/- 2 beats.min-1, respectively) compared with the control group. In all groups, plasma epinephrine and norepinephrine concentrations increased after administration of 2% and 1% isoflurane, respectively. Plasma lidocaine concentrations were 0.3-1.3 micrograms.kg-1 in the nasal lidocaine group and 0.6-1.5 micrograms.kg-1 in the intravenous lidocaine group. CONCLUSIONS: Stepwise increases in isoflurane concentration elicited hypertension and tachycardia as well as increments in plasma catecholamine concentrations during mask anesthesia. Nasal administration of lidocaine and clonidine premedication significantly blunted the circulatory responses to isoflurane. Intravenous lidocaine did not significantly weaken the responses to changes in isoflurane concentration.

Administration, Topical↗

PubMed1994

Fallout radioactivity in soil and food samples in the Ukraine: measurements of iodine, plutonium, cesium, and strontium isotopes.

To estimate the level and distribution of fallout attributable to the 26 April 1986 Chernobyl nuclear power station accident in the Ukraine, we sampled several kinds of substances at Korosten, Zhitomir and at Katyuzhanka, Vishgorod, Kiev in the Ukraine, and measured the radioactivity of 137Cs, 134Cs, 90Sr, 129I, 238Pu, 239,240Pu, and the density of 127I (stable). The substances investigated were soil, dry milk, wheat, rye, drinking water, and mushrooms. Except for the mushrooms collected, which were sampled at Katyuzhanka, Vishgorod, and at Kiev, all substances were at Korosten, Zhitomir. The activity of 137Cs, 134Cs, 90Sr, 238Pu, and 239,240Pu were all higher in soil and mushrooms than in the other four substances. The activity of 137Cs was 960 and 1,210 Bq kg-1 in the two soil samples and 6,110 Bq kg-1 in the mushrooms. The activity of 134Cs was approximately 15% of 137Cs in the two soil samples while < 3% of 137Cs in the mushrooms. The activity concentration level of 90Sr as compared to 137Cs concentration was 15-31% in food samples other than mushrooms but only 1.9% in mushrooms and 1.4 and 1.2% in the two soil samples. The radioactivity ratios, 238Pu: 239,240Pu and 239,240Pu: 137Cs, suggested that the proportion of cesium radioisotopes and 239,240Pu in the soil attributable to the Chernobyl accident was approximately 100% and 10-20%, respectively, while approximately 100% of 239,240Pu in the mushrooms was attributable to the accident. The activity of 129I was small but the ratio of 129I: 127I in the two soil samples was 4.3 x 10(-8) and 1.0 x 10(-7), which is approximately 10 times larger than that in the global fallout. These results suggest that the areas where the soil was sampled are iodine-deficient and were contaminated slightly by the Chernobyl accident.

Accidents↗

PubMed1994

137Cs concentration among children in areas contaminated with radioactive fallout from the Chernobyl accident: Mogilev and Gomel oblasts, Belarus.

The level of radiation exposure in children in Belarus caused by the Chernobyl accident was investigated on the basis of whole body 137Cs count. The subjects were 10,062 children (4,762 boys and 5,300 girls) in Mogilev and Gomel, Belarus, who received Chernobyl Sasakawa Health and Medical Cooperation Project health examinations from May 1991 to December 1992 and who were 5-16 y old at the time of examination. The median whole body 137Cs count per body weight varied from 21-48 Bq kg-1 and from 28-126 Bq kg-1 in Mogilev oblast and Gomel oblast, respectively. (The "oblast" is the largest administrative district constituting the country. Belarus consists of 6 oblasts). Corresponding annual effective dose equivalents were all less than the public dose limit of 1 mSv y-1, but the observed levels in the children were considerably higher than the average level of 2.3 Bq kg-1 reported in the past for the former Soviet Union.

Accidents↗

PubMed1994

Developmental change in activity of red cell porphobilinogen deaminase and its electrophoretic variant in the Japanese population.

The activity of porphobilinogen deaminase (PBGD), an enzyme whose partial deficiency is associated with acute intermittent porphyria (AIP), changes during development. Little is known about the postnatal change of PBGD activity and the prevalence of its electrophoretic variant in the Japanese population. The activity of PBGD was measured fluorometrically in 194 infants aged 0-12 months, while isoelectric focusing of PBGD was performed in 400 healthy Japanese adults aged 20-45 years and 30 children with various hematological disorders aged 1-15 years. The PBGD level was 1.9 times higher in the neonates than in the adults, decreased abruptly during the first month of life, and reached the adult level at the age of 9 months. None of the 400 healthy Japanese adults and the 30 children with hematological disorders showed any electrophoretic variant. These results suggest that there is no need to consider any polymorphism in the gene dose study of PBGD and that the biochemical screening of AIP is applicable to since the late infancy.

Adult↗

PubMed1994

Descending control of nonspiking local interneurons in the terminal abdominal ganglion of the crayfish.

1. Electrical stimulation of afferents innervating an exopodite causes a closing pattern of activity in the uropod motor neurons. In this reflex two distinct types of nonspiking local interneurons, posterolateral (PL) and anterolateral (AL) types, classified by their gross morphology and somata location, receive sensory inputs and control the motor output to the uropod. 2. In the sensory-motor pathway, the PL and AL nonspiking local interneurons formed opposing and parallel connections with uropod motor neurons. For example, the PL interneurons that excited the closer, reductor motor neuron by injecting depolarizing current received depolarizing postsynaptic potentials (PSPs), whereas the AL interneurons of the same output received hyperpolarizing PSPs. The PL interneurons that inhibited the reductor motor neuron received hyperpolarizing PSPs, whereas the AL interneurons of the similar output received depolarizing PSPs. 3. During fictive abdominal extension, induced by electrical stimulation of extension-evoking command fibers in the second-third abdominal connective, the uropod motor neurons show an opening pattern of activity that is opposite to the pattern elicited by sensory stimulation. Furthermore, sensory stimulation during ongoing fictive abdominal extension has little effect on the uropod motor neurons. 4. Except for the nonspiking local interneurons, the majority of other local circuit neurons, i.e., spiking local interneurons and ascending interneurons, are not driven by the descending inputs during abdominal extension. 5. A comparison of the responses of the nonspiking local interneurons to both sensory and descending inputs reveals that the majority of nonspiking local interneurons receive both inputs, but the sign of response to each is frequently opposite. This study suggests that the degree of excitability of two distinct types of PL and AL nonspiking local interneurons induced by sensory inputs changes depending on whether the crayfish is in a resting posture or is active with full extension of the abdomen. Ongoing abdominal extension in swimming or defensive crayfish would shift the gain of reflex pathways through the PL and AL interneurons, and motor response resulting from sensory inputs would be modulated.

Abdomen↗