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Y Yamaji

Publications and source records attributed to Y Yamaji.

At least 37 records · Page 2Linked to original sources

Examination of angiotensin II type 1 and type 2 receptor expression in human kidneys by immunohistochemistry.

Recent studies have suggested that both the angiotensin II type 1 (AT1) and type 2 (AT2) receptors may be involved in the control of renal function in rodents. The aim of this study was to examine the distribution of these receptors in normal and diseased human kidneys. Kidney samples were obtained from 21 patients with and without glomerular lesions (3 control kidney samples from patients undergoing nephrectomy, 4 patients with minimal change disease, 6 patients with IgA nephropathy, and 8 patients with membranous glomerulonephritis). AT1 receptor immunohistochemical staining was examined and found to be most prominent in blood vessels, but staining of the tubules and glomeruli was also seen. In the case of the AT2 receptor, mild-moderate immunohistochemical staining was seen in the blood vessels, with weaker staining in the glomeruli. A similar distribution was seen in the patients with glomerulopathy. These results suggest that both AT1 and AT2 receptors are expressed in the normal human kidney, as well as in patients with glomerular disease. The histological distribution of these receptors supports the notion that both receptors may have a physiological role in normal and diseased kidneys in humans.

Female↗

Expression of carcinoembryonic antigen in peripheral- or central-located small cell lung cancer: its clinical significance.

BACKGROUND: Small cell lung cancer (SCLC) has a higher percentage of hilar masses than other histological types of lung cancer. The primary site is usually adjacent to the hilum, but we often observe primary sites in the peripheral lung field. In this study, our objectives were to elucidate whether peripheral-located small cell lung cancer (PSCLC) is an independent entity and whether it differs clinically from central-located small cell lung cancer (CSCLC). METHODS: We reviewed the clinical and pathological features of 52 patients treated at Kagawa Medical University Hospital between 1987 and 1996 with a diagnosis of SCLC. We defined CSCLC as a tumor whose primary site is located in the segmental bronchi or more proximally and PSCLC as a tumor located distal to the subsegmental bronchi. Twenty-one PSCLC patients and 31 CSCLC patients were identified. Kaplan-Meier survival curves were constructed and comparisons were made between PSCLC and CSCLC by the log-rank test. The carcinoembryonic antigen (CEA) level was also evaluated in each group. RESULTS: Although the percentage of limited disease (LD) in the patients with PSCLC was higher than that in the patients with CSCLC, the 3-year survival rate of PSCLC tended to be worse than that of CSCLC (9% for patients with PSCLC and 29% for those with CSCLC). Survival curves of patients with PSCLC also tended to be worse than those of patients with CSCLC, not only in the limited disease group but also in the extensive disease (ED) group. In addition, the mean CEA value in patients with PSCLC was higher than that in patients with CSCLC (p < 0.001), whereas the neuron specific enolase (NSE) level was not significantly different between PSCLC and CSCLC. The median survival of patients with pretherapeutic CEA titers of > or =5 ng/ml was significantly shorter than that in patients with CEA levels <5 ng/ml. CONCLUSION: These findings suggest that the survival of SCLC patients with a high CEA level was significantly shorter than that of patients with a low CEA level. In addition, CEA levels in PSCLC patients were significantly higher than those in CSCLC patients. However, the survivals of LD or ED patients with PSCLC and CSCLC were not statistically different.

Adenocarcinoma↗

Frameshift mutations at mononucleotide repeats in RAD50 recombinational DNA repair gene in colorectal cancers with microsatellite instability.

To identify additional genes targeted for microsatellite instability (MSI), we search for human genes which contain mononucleotide repeats in their coding region, selected 7 genes (RAD50, DNA-PKcs, FLASH, Apaf-1, XPG, CtIP, and MLSN1), and analyzed frameshift mutations in them. Here we report that 60% (3 out of 5) of human colorectal cancer cell lines exhibiting a high frequency of MSI (MSI-H) and 46% (6 out of 13) of MSI-H primary colorectal tumors had mutations in the (A)9 repeat of RAD50 recombinational repair gene. In contrast, no frameshift mutations were found in any of the 5 MSI-negative colorectal cancer cell lines, 8 colorectal tumors exhibiting a low frequency of MSI (MSI-L), or 28 MSI-negative colorectal tumors. No mutations were found in the mononucleotide repeats of 6 other genes, even in MSI-H cancers. These results suggest that RAD50 frameshift mutations may play a role in the tumorigenesis of MSI-H colorectal cancers.

Colorectal Neoplasms↗

Helicobacter pylori activates the cyclin D1 gene through mitogen-activated protein kinase pathway in gastric cancer cells.

Helicobacter pylori induces cellular proliferation in host cells, but the mechanism remains unclear. Thus, we examined the effect of H. pylori on cyclin D1, an important regulator of the cell cycle, especially in relation to intracellular signaling pathways. In a Northern blot analysis, cyclin D1 transcription in gastric cancer (AGS) cells was enhanced by coculture with H. pylori strain TN2 in a time-dependent and multiplicity-of-infection-dependent manner. An isogenic mutant form of vacA also increased cyclin D1 transcription, but mutant forms of cagE or the entire cag pathogenicity island did not enhance cyclin D1 transcription. These effects were confirmed with a luciferase assay of the cyclin D1 promoter (pD1luc). Cyclin D1 promoter activation by H. pylori was inhibited by MEK inhibitors (U0126 and PD98059), indicating that the mitogen-activated protein kinase pathway may be involved in intracellular signal transduction. In contrast, transfection of a reporter plasmid having any point mutations of the NF-kappaB binding sites in the promoter (pD1-kappaB1M, pD1-kappaB2M, or pD1-kappaB1/2M) or cotransfection of dominant negative IkappaBalpha did not affect cyclin D1 activation by H. pylori. In conclusion, H. pylori activates cyclin D1 through the mitogen-activated protein kinase pathway and not through NF-kappaB activation in AGS cells. This activation of cyclin D1 is partly dependent on the cag pathogenicity island but not on vacA.

Cyclin D1↗

Inverse background of Helicobacter pylori antibody and pepsinogen in reflux oesophagitis compared with gastric cancer: analysis of 5732 Japanese subjects.

BACKGROUND: The relationship between Helicobacter pylori and reflux oesophagitis remains controversial. AIMS: To evaluate the relationship between H pylori and reflux oesophagitis in a large number of Japanese subjects. SUBJECTS: A total of 5732 consecutive Japanese subjects during a health screening were enrolled. METHODS: Gastrointestinal endoscopy was performed on all subjects. We simultaneously measured serum anti-H pylori antibody and pepsinogen as markers of H pylori infection together with gastric atrophy. The risk of reflux oesophagitis was evaluated in relation to these markers, and the results were compared with those of gastric cancer. RESULTS: Reflux oesophagitis was found in 108 subjects. Both positivity for H pylori antibody (adjusted odds ratio (OR) 0.67 (95% confidence interval 0.45-1.0)) and "low" pepsinogen indicating gastric atrophy (OR 0.35 (0.18-0.68)) were negatively associated with reflux oesophagitis. After subjects were classified into four groups based on positivity or negativity for H pylori antibody and "low" pepsinogen, the prevalence of reflux oesophagitis showed a decreasing trend as H pylori induced gastric atrophy became more severe. The risk of gastric cancer showed an increasing trend, exactly the opposite to that of reflux oesophagitis. CONCLUSIONS: Analysis of a large series of Japanese subjects revealed a decreasing prevalence of reflux oesophagitis in conjunction with progress of gastric atrophy induced by H pylori infection. This pattern was completely opposite to that of gastric cancer cases. A protective role of H pylori for reflux oesophagitis through the development of gastric atrophy has been suggested.

Adult↗

Assessment of gastric carcinoma risk associated with Helicobacter pylori may vary depending on the antigen used: CagA specific enzyme-linked immunoadsorbent assay (ELISA) versus commercially available H. pylori ELISAs.

BACKGROUND: Previous epidemiologic studies produced inconsistent results when examining the relation between Helicobacter pylori infection and the risk of gastric carcinoma by measuring various anti-H. pylori antibodies. This study investigated the increased risk of cancer by examining different antibodies, including the specific anti-CagA antibody and antibodies from two commercially available kits. METHODS: An ELISA for the detection of serum anti-CagA was established using a recombinant CagA protein that the authors previously reported. Serum anti-CagA titer was determined for 80 patients with gastric carcinoma and 80 gender- and age-matched controls. Two anti-H. pylori antibodies from the commercially available kits HEL-p (Amrad, Kew Vic, Australia) and HM-CAP (Enteric Product Inc., Westbury, NY) were also evaluated. RESULTS: Anti-CagA seropositivity differed significantly between gastric carcinoma patients and controls (92.5% vs. 55.0%; P = 0. 0001), showing an odds ratio of 10.4 (95% confidence interval [CI]: 4.23-29.74). The difference was less prominent for the seropositivity of HEL-p (77.5% vs. 58.8%; P = 0.0139; odds ratio: 2. 38; 95% CI: 1.20-4.82) and insignificant for that of HM-CAP (65.0% vs. 57.5%; P = 0.4325; odds ratio: 1.30; 95% CI: 0.68-2.49). CONCLUSIONS: The current study revealed that the antibody assay system used could be one important factor in the assessment of gastric carcinoma risk for patients with H. pylori.

Adult↗

Mechanisms of the release of CYFRA21-1 in human lung cancer cell lines.

The CYFRA 21-1 assay which detects cytokeratin 19 (CK19) fragment is widely used as a tumor marker for lung cancer. However, the reason why some lung cancer cell lines release CK19 fragment in culture supernatants and others do not, remains unclear. It was hypothesized that the release of CK19 fragment may be elucidated by the expression of mRNA for CK19. In order to prove this, the mRNA for CK19 was quantitatively evaluated by the competitive reverse transcriptase-polymerase chain reaction (competitive RT-PCR). The level of CYFRA 21-1 in the culture supernatant was measured by an immunoradiometric assay. CK19 protein synthesis was evaluated by a Western blotting and immunohistochemistry. Fourteen lung cancer cell lines were evaluated, and the amount of mRNA correlated well with the level of CYFRA 21-1 in culture supernatants. Analysis of genomic DNA for CK19 demonstrated that three cell lines which could not produce CYFRA 21-1, conjectured that some abnormalities in exon 1 or the 5'-region upstream from exon 1. In conclusion, it was demonstrated that the release of CK19 fragment was closely related to the expression of mRNA for CK19, and the possibility that genomic change of CK19 DNA down-regulated the expression of mRNA for CK19 was suggested.

Antigens, Neoplasm↗

Organization of somatic motor inputs from the frontal lobe to the pedunculopontine tegmental nucleus in the macaque monkey.

To reveal the somatotopy of the pedunculopontine tegmental nucleus that functions as a brainstem motor center, we examined the distribution patterns of corticotegmental inputs from the somatic motor areas of the frontal lobe in the macaque monkey. Based on the somatotopical map prepared by intracortical microstimulation, injections of the anterograde tracers, biotinylated dextran amine and wheat germ agglutinin-conjugated horseradish peroxidase, were made into the following motor-related areas: the primary motor cortex, the supplementary and presupplementary motor areas, the dorsal and ventral divisions of the premotor cortex, and the frontal eye field. Data obtained from the present experiments were as follows: (i) Corticotegmental inputs from orofacial, forelimb, and hindlimb representations of the primary motor cortex tended to be arranged orderly from medial to lateral in the pedunculopontine tegmental nucleus. However, the distribution areas of these inputs considerably overlapped; (ii) The major input zones from distal representations of the forelimb and hindlimb regions of the primary motor cortex were located medial to those from their proximal representations, although there was a substantial overlap between the distribution areas of distal versus proximal limb inputs; (iii) The main terminal zones from the forelimb regions of the primary motor cortex, the supplementary and presupplementary motor areas, and the dorsal and ventral divisions of the premotor cortex appeared to overlap largely in the mediolaterally middle aspect of the pedunculopontine tegmental nucleus; and (iv) Corticotegmental input from the frontal eye field was scattered over the pedunculopontine tegmental nucleus.Thus, the present results indicate that the pedunculopontine tegmental nucleus is likely to receive partly separate but essentially convergent cortical inputs not only from multiple motor-related areas representing the same body part, but also from multiple regions representing diverse body parts. This suggests that somatotopical representations are intermingled rather than segregated in the pedunculopontine tegmental nucleus.

Animals↗

Protection against dopaminergic nigrostriatal cell death by excitatory input ablation.

The importance of enhanced glutamatergic neurotransmission in the basal ganglia and related structures has recently been highlighted in the development of Parkinson's disease. The pedunculopontine tegmental nucleus (PPN) is the major origin of excitatory, glutamatergic input to dopaminergic nigrostriatal neurons of which degeneration is well known to cause Parkinson's disease. Based on the concept that an excitatory mechanism mediated by glutamatergic neurotransmission underlies the pathogenesis of neurodegenerative disorders, we made an attempt to test the hypothesis that removal of the glutamatergic input to the nigrostriatal neurons by PPN lesions might prevent 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism in the macaque monkey. The PPN was lesioned unilaterally with microinjection of kainic acid, and, then, MPTP was administered systemically. In these monkeys, the degree of parkinsonian motor signs was behaviourally evaluated, and the histological changes in the dopaminergic nigrostriatal system were analysed by means of tyrosine hydroxylase immunohistochemistry. The present results revealed that nigrostriatal cell loss and parkinsonian motor deficits were largely attenuated in the MPTP-treated monkey group whose PPN had been lesioned, compared with the control, MPTP-treated monkey group with the PPN intact. This clearly indicates that the onset of MPTP neurotoxicity is suppressed or delayed by experimental ablation of the glutamatergic input to the nigrostriatal neurons. Such a protective action of excitatory input ablation against nigrostriatal cell death defines evidence that nigral excitation driven by the PPN may be implicated in the pathophysiology of Parkinson's disease.

Animals↗

H. pylori activates NF-kappaB through a signaling pathway involving IkappaB kinases, NF-kappaB-inducing kinase, TRAF2, and TRAF6 in gastric cancer cells.

BACKGROUND & AIMS: H. pylori infection on gastric epithelial cells has been shown to induce NF-kappaB activation, but the mechanism of intracellular signal conduction that leads to NF-kappaB activation is not clear. The aim of this study was to analyze the molecular mechanism responsible for H. pylori-mediated NF-kappaB activation on gastric cancer cells. METHODS: NF-kappaB activation by H. pylori was tested by using luciferase reporter assay. IkappaBalpha degradation by H. pylori infection was assessed by immunoblotting. IKKalpha and IKKbeta activation was analyzed by kinase assay. In transfection experiments, effects of dominant negative IkappaBalpha, IKKalpha, IKKbeta, NF-kappaB-inducing kinase (NIK), TRAF2, and TRAF6 mutants were investigated. The effects of an IKKbeta-specific inhibitor, aspirin, on NF-kappaB activation and IL-8 secretion were also analyzed. RESULTS: H. pylori promotes degradation of IkappaBalpha, a cytoplasmic inhibitor of NF-kappaB. In kinase assay, H. pylori induced IKKalpha and IKKbeta catalytic activity in gastric cancer cells. Transfection of kinase-deficient mutant of either IKK inhibited H. pylori-mediated NF-kappaB activation dose-dependently. Aspirin inhibited both NF-kappaB activation and IL-8 secretion induced by H. pylori. NF-kappaB activation was also inhibited by transfection of kinase-deficient NIK or a dominant negative mutant of upstream adapter protein TRAF2 or TRAF6. CONCLUSIONS: H. pylori induces NF-kappaB activation through an intracellular signaling pathway that involves IKKalpha, IKKbeta, NIK, TRAF2, and TRAF6.

Aspirin↗

The effects of calcium channel blockers on nuclear factor kappa B activation in the mesangium cells.

It has been reported that calcium channel blockers (CCBs) have an inhibitory action on cell growth and transcriptional changes induced by cytokines and hormones. In this study, we examined the effects of CCBs on nuclear factor kappa B (NFkappaB), which plays a key role in the intracellular signaling of various growth factors and cytokines. The activity of NFkappaB was determined by luciferase assay with the transfection of the reporter gene, which has six NFkappaB-recognizing sequences in the upstream of herpes simplex virus thymidine kinase promoter. In cultured human mesangial cells, increased intracellular calcium concentration by calcium ionophore, A23187, showed a stimulatory effect on the phorbor 12-myristate 13-acetate (PMA)-induced activation of NFkappaB, while L-type calcium channel agonist, Bay K 8644, did not have any significant effects on either basal or PMA-stimulated activity of NFkappaB. At a higher concentration (10 microM), nifedipine, verapamil, or efonidipine showed an inhibitory effect on the activation of NFkappaB by PMA and A23187, while at a lower concentration (1 microM), only efonidipine showed a significant inhibitory effect. From these results, we conclude that CCBs have an inhibitory effect on NFkappaB via the independent pathway of an L-type calcium channel and that the potency of this effect is variable among L-type calcium channel blockers.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗

Expression of cytokeratin 19 mRNA in human lung cancer cell lines.

The present study was designed to clarify the mechanism by which some lung cancer cell lines can produce cytokeratin 19 (CK19) fragment and others cannot. We hypothesized that some lung cancer cell lines which cannot release CK19 express an incomplete sequence of CK19 mRNA. Expression of mRNA was evaluated by RT-PCR using several primer pairs for CK19. CK19 in the culture supernatant was measured by an immuno-radiometric assay. CK19 protein synthesis was evaluated by Western immunoblot and immunohistochemistry. Among 16 lung cancer cell lines, 7 released significant amounts of CK19 in the supernatant. In some cell lines, expression of CK19 mRNA was observed only in some combinations of primers, suggesting that incomplete mRNA was expressed. 3'-RACE analysis detected amplified products of a shorter size compared with normal amplified products in cell lines which expressed incomplete CK19 mRNA, suggesting that 3'-ends of mRNA for CK19 were deleted. Results of Western immunoblot and immuno-histochemical staining using anti-human CK19 monoclonal antibody completely correlated with the results on CK19 levels in culture supernatants as well as with complete expression of mRNA. We conclude that levels of CK19 closely relate to the expression of complete mRNA for CK19.

Adenocarcinoma↗

Clinical features of non-specific interstitial pneumonia.

The clinical features of 24 patients with non-specific interstitial pneumonia (NIP) were evaluated. The patients consisted of seven men and 17 women, with a median age of 60 years. In seven patients, the disease was idiopathic and eight had collagen vascular diseases. Cough, dyspnoea and fever were frequently observed. The time interval between the onset of symptoms and open lung biopsy was 3 months. Mild increases of IgG, CRP, and LDH were also frequently observed. The average per cent VC was 65.1 +/- 3.2% and the average PaO2 was 71.3 +/- 2.4 Torr. Bronchoalveolar lavage was done in 20 patients, and a moderate increase in lymphocytes (27.8 +/- 6.7%) with a low CD4/CD8 ratio (0.86 +/- 0.22) was observed. Multiple patchy infiltration or diffuse interstitial shadows, located predominantly in the lower fields of both lungs were the characteristic chest CT findings. Lung biopsies in this group were characterized by varying proportions of chronic interstitial inflammation and fibrosis which was temporarily uniform. Patients were given steroid pulse therapy or oral steroids. The results were mild to marked improvements in chest roentgenographic findings and lung functions. Four patients (16.7%) died because of respiratory failure caused by NIP. This is the first report to describe clinical features of NIP since the original report by Katzenstein and Fiorelli.

Adrenal Cortex Hormones↗

Expression of nerve growth factor-induced clone B subfamily and pro-opiomelanocortin gene in lung cancer cell lines.

Nerve growth factor-induced clone B (NGFI-B), Nur-related factor 1, and neuron-derived orphan receptor-1 have structural features of ligand-activated transcriptional regulators and constitute the NGFI-B subfamily within the nuclear receptor superfamily. The NGFI-B subfamily is highly expressed in neuroendocrine organs and regulates the pro-opiomelanocortin (POMC) gene. Small-cell lung cancer (SCLC) is considered to be a neuroendocrine tumor that produces large numbers of polypeptide hormones. In this study we measured the NGFI-B subfamily and POMC messenger RNA (mRNA) levels in various lung-cancer cell lines by means of the quantitative reverse transcription-polymerase chain reaction, and evaluated the correlations between expression of these genes and polypeptide hormone productions. We also examined the effect of antisense oligonucleotide to NGFI-B mRNA on the expression of POMC mRNA. The NGFI-B subfamily and POMC mRNAs were highly expressed in SCLC cell lines. In addition, there were strong correlations between the NGFI-B, POMC genes, and the adrenocorticotropin hormone (ACTH) level. Further, the antisense oligonucleotide significantly suppressed POMC gene expression. We conclude that the NGFI-B subfamily was a significant molecule in SCLC and that the NGFI-B was a positive transcriptional factor for ACTH production.

Carcinoma, Non-Small-Cell Lung↗

Overexpression of p53 protein in interstitial lung diseases.

The p53 gene is well known as a tumour suppressor gene. In addition, the mutated p53 gene is detected in a variety of human cancers including lung cancer, and is considered as an oncogene. Lung cancer is also frequently associated with interstitial lung diseases. Therefore, it may be possible to hypothesize that there might be some abnormality of p53 gene in interstitial lung diseases. This work examined the relationship between the p53 protein and gene in lung tissues of 28 patients with interstitial lung diseases. Among 28 patients, 13 cases were pathologically diagnosed to have usual interstitial pneumonia (UIP), 12 cases were diagnosed as having collagen vascular lung diseases, and three cases were diagnosed to have a non-specific interstitial pneumonia. Twenty-three tissue samples were obtained by open lung biopsy and five samples were taken by autopsy. Paraffin-embedded tissues were treated by microwave, and stained with an anti-p53 antibody (DO7) by the Avidin-Biotin-Peroxidase (ABC) method. In selected patients, mutations in exons 5-8 of the p53 gene were also examined by single-strand conformation polymorphism (SSCP) analysis and DNA sequence. In addition, the presence of anti-p53 antibodies in patients' sera was screened for by ELISA. Fifteen samples (53.6%) revealed overexpression of the p53 protein in the nuclei of alveolar epithelial cells. However, SSCP or sequence analysis, which was performed in 13 tissues, showed no mutations in exons 5-8 of the p53 gene. In conclusion, p53 proteins were overexpressed in interstitial lung diseases, and the expressed p53 protein was considered to be wild-type. This wild-type p53 protein may play a role in blocking the transformation of proliferative epithelial cells.

Adult↗

Heterogeneous point mutations of the p53 gene in pulmonary fibrosis.

Lung cancer is a frequent complication in pulmonary fibrosis. Overexpression of p53 proteins has been demonstrated by immunostaining in bronchoepithelial cells in patients with idiopathic pulmonary fibrosis. However, it is still unclear whether this overexpressed p53 protein is wild-type or mutant. It was hypothesized that pulmonary fibrosis may be a precancerous lesion with deoxyribonucleic acid point mutations in bronchoepithelial cells. Mutations of the p53 gene were tested for by fluorescence-based single-strand conformation polymorphism (FSSCP), cloning-sequencing and immunostaining techniques. Out of 10 tissue samples that demonstrated overexpression of p53 protein by immunostaining, nine (90%) exhibited point mutations and eight (80%) exhibited heterogeneous point mutations of the p53 gene. The mutations found in pulmonary fibrosis were scattered throughout the central part of the p53 gene, and both guanine (G):cytosine (C) to adenine (A):thymine (T) and A:T to G:C transitions were frequently observed. In conclusion, frequent heterogeneous point mutations of the p53 gene were detected in pulmonary fibrosis. These mutations may have resulted from several types of deoxyribonucleic acid damage that occurred in bronchoepithelial cells and this may explain previous findings of a very high incidence of lung cancer complicating pulmonary fibrosis.

Adult↗

Excitotoxic lesions of the pedunculopontine tegmental nucleus produce contralateral hemiparkinsonism in the monkey.

Dopaminergic nigrostriatal neurons, degeneration of which causes Parkinson's disease, are known to receive excitatory input almost exclusively from the pedunculopontine tegmental nucleus (PPN). We report here that excitotoxic lesions of the PPN produce abnormal motor signs relevant to hemiparkinsonism in the macaque monkey. Under the guidance of extracellular unit recordings, the electrophysiologically identified PPN was injected unilaterally with kainic acid. These PPN-lesioned monkeys exhibited mild to moderate levels of flexed posture and hypokinesia in the upper and lower limbs contralateral to the lesion. In most of the monkeys, such pathophysiological events were gradually improved and became stationary in 1-2 weeks. The hemiparkinsonian symptoms observed after PPN destruction might be ascribed to a decrease in nigrostriatal neuron activity due to excitatory input ablation.

Animals↗