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PubMed2004

Guidelines for monitoring bulk tank milk somatic cell and bacterial counts.

This study was conducted to establish guidelines for monitoring bulk tank milk somatic cell count and bacterial counts, and to understand the relationship between different bacterial groups that occur in bulk tank milk. One hundred twenty-six dairy farms in 14 counties of Pennsylvania participated, each providing one bulk tank milk sample every 15 d for 2 mo. The 4 bulk tank milk samples from each farm were examined for bulk tank somatic cell count and bacterial counts including standard plate count, preliminary incubation count, laboratory pasteurization count, coagulase-negative staphylococcal count, environmental streptococcal count, coliform count, and gram-negative noncoliform count. The milk samples were also examined for presence of Staphylococcus aureus, Streptococcus agalactiae, and Mycoplasma. The bacterial counts of 4 bulk tank milk samples examined over an 8-wk period were averaged and expressed as mean bacterial count per milliliter. The study revealed that an increase in the frequency of isolation of Staphylococcus aureus and Streptococcus agalactiae was significantly associated with an increased bulk tank somatic cell count. Paired correlation analysis showed that there was low correlation between different bacterial counts. Bulk tank milk with low (<5000 cfu/mL) standard plate count also had a significantly low level of mean bulk tank somatic cell count (<200,000 cells/mL), preliminary incubation count (<10,000 cfu/mL), laboratory pasteurization count (<100 cfu/mL), coagulase-negative staphylococci and environmental streptococcal counts (<500 cfu/mL), and noncoliform count (<200 cfu/mL). Coliform count was less likely to be associated with somatic cell or other bacterial counts. Herd size and farm management practices had considerable influence on somatic cell and bacterial counts in bulk tank milk. Dairy herds that used automatic milking detachers, sand as bedding material, dip cups for teat dipping instead of spraying, and practiced pre-and postdipping had significantly lower bulk tank somatic cell and/or bacterial counts. In conclusion, categorized bulk tank somatic cell and bacterial counts could serve as indicators and facilitate monitoring of herd udder health and milk quality.

Animals↗
PubMed1986

Use of laboratory mice to study genetic relationships among milk yield and number of somatic cells.

Preliminary results of bidirectional selection for increased and decreased somatic cell counts in milk of laboratory mice were used to assess the usefulness of the laboratory mouse as a pilot organism for the study of yield and somatic cell count relationships in dairy cattle. Procedures developed permit relatively rapid and accurate determination of somatic cell counts in milk of mice. Concentration of somatic cells was three to four times greater in mice than in dairy cows, but counts were distributed similarly. A large effect for stage of lactation existed with high counts in late lactation. Within lactation, repeatability of somatic cell counts and relationships between somatic cell counts and milk yield were similar to those reported for dairy cattle. Heritability of lactation average somatic cell count (3 sample d, log base 2, adjusted for stage of lactation) was .24, indicating lines genetically divergent for somatic cell count can be developed.

Animals↗
PubMed1993

Absence of quadratic relationships between genetic evaluations for somatic cell scores and udder linear traits.

Sire genetic evaluations for lactation average somatic cell scores from first and second lactation daughters were regressed in separate models on genetic evaluations for udder linear traits. Somatic cell scores were from Pennsylvania DHIA, and udder linear scores were from the Holstein Association of America classifications of first lactation cows in the northeastern US excluding Pennsylvania. The independent data files for calculation of genetic evaluations included 108,632 cows from 301 sires with udder linear scores and 58,235 cows from the same 301 sires with somatic cell scores. Sire genetic evaluations for higher udders, stronger fore udder attachments, closer teat placement, and shorter teats were associated with lower somatic cell scores. Quadratic relationships between genetic evaluations for the udder traits and somatic cell scores were not important. Quadratic components were significant only for somatic cell scores and teat length. Evaluations for intermediate teat length tended to be associated with higher somatic cell score evaluations. Selection and mating for intermediate udder depth, fore udder attachment, and front teat placement scores are not as effective in reducing somatic cell scores as selection for higher udders, stronger fore udders, and closer front teats.

Animals↗
PubMed1994

Selection on somatic cell score to improve resistance to mastitis in the United States.

Increased genetic susceptibility to mastitis has accompanied the rapid genetic increase in milk yield, and genetic selection for mastitis resistance should be considered. Somatic cell score is recommended as an indicator trait to achieve genetic improvement for mastitis resistance. Heritability of somatic cell score is around 10%, and genetic correlation between somatic cell score and clinical mastitis is around .6 to .8. Selection for lower somatic cell score is consistent with the goal of maximizing genetic improvement for total economic merit and should be included in breeding programs. National genetic evaluations for somatic cells scores will use the same animal models and methods as are currently used for milk yield traits. Reliabilities of PTA for somatic cell scores will be smaller than for yield traits because of lower heritability and availability of records from fewer cows. Several forms are proposed for reporting genetic evaluations of somatic cells to producers, and advantages and disadvantages are discussed. Using somatic cell scores for breeding decisions would marginally decrease genetic gain for milk yield and increase total economic merit. Optimal selection indexes would slow the rate of increase in mastitis, rather than decrease its incidence.

Animal Husbandry↗
PubMed1994

Using somatic cell score evaluations for management decisions.

Genetic evaluations for mean somatic cell scores for lactation enable producers to reduce increases in SCC that accompany genetic improvement for milk yield. Current progeny test designs will produce lower reliabilities for somatic cell score evaluations than for milk yield because of lower heritability. Genetic correlations of somatic cell scores between first and second lactation are lower than for milk yield. Thus, changes in evaluations of sires over time should be greater for somatic cell score than for milk yield. Absence of interaction of genotype and environment for somatic cell score indicates that the same bulls would be selected for use in herds with high and low somatic cell scores. Most evaluations will be between -.25 and .25, averaging .01 for Holsteins, which represents an increase of approximately 50% in geometric mean SCC and an 11% higher incidence of clinical mastitis for daughters of bulls with highest evaluations compared with daughters of bulls with lowest evaluations. Selection to reduce somatic cell score does not appear to be justified economically. Properly constructed indexes would reduce the projected increases in mastitis incidence by 20 to 25% with a 2% decline in genetic progress for milk yield. The greatest impact of genetic evaluations for somatic cell score would likely result from choice of sires of bulls to progeny test.

Animals↗
PubMed2001

The targeting of somatic hypermutation closely resembles that of meiotic mutation.

We have compared the microsequence specificity of mutations introduced during somatic hypermutation (SH) and those introduced meiotically during neutral evolution. We have minimized the effects of selection by studying nonproductive (hence unselected) Ig V region genes for somatic mutations and processed pseudogenes for meiotic mutations. We find that the two sets of patterns are very similar: the mutabilities of nucleotide triplets are positively correlated between the somatic and meiotic sets. The major differences that do exist fall into three distinct categories: 1) The mutability is sharply higher at CG dinucleotides under meiotic but not somatic mutation. 2) The complementary triplets AGC and GCT are much more mutable under somatic than under meiotic mutation. 3) Triplets of the form WAN (W = T or A) are uniformly more mutable under somatic than under meiotic mutation. Nevertheless, the relative mutabilities both within this set and within the SAN (S = G or C) triplets are highly correlated with those under meiotic mutation. We also find that the somatic triplet specificity is strongly symmetric under strand exchange for A/T triplets as well as for G/C triplets in spite of the strong predominance of A over T mutations. Thus, we suggest that somatic mutation has at least two distinct components: one that specifically targets AGC/GCT triplets and another that acts as true catalysis of meiotic mutation.

Base Sequence↗
PubMed1999

Somatic alterations and metabolic polymorphisms.

Cancer is a multistep process in which multiple genetic alterations occur, causing a cumulative adverse effect on the control of cell differentiation, cell division and growth control. Somatic alterations acquired at the level of the cell become fixed in the developing cancer as chromosomal translocations, deletions, inversions, amplifications or point mutations. Since the ultimate unit of susceptibility to carcinogens is at the level of the cell, somatic gene alterations play an important role in carcinogenesis, as all neoplastic tumours exhibit somatic alterations. The incorporation of somatic alterations, such as oncogenes and tumour-suppressor genes, into epidemiological research provides an opportunity to clarify the role of exposure, other genetic changes and prognosis in cancer pathogenesis. The manner in which environmental factors act to initiate, accelerate or retard neoplastic progression Is currently being investigated using somatic gene mutational spectra to identify specific etiological carcinogens. Exploring the relationships between germline and somatic alterations may help to identify the timing of genetic events, important etiological exposures and gene-gene epistatic phenomena. Examining somatic alterations within the context of carcinogen-metabolizing enzymes may elucidate specific carcinogenic mechanisms. The use of somatic alterations to predict prognoses for patients with various malignancies may also help to enhance our ability to define subgroups of patients with different disease courses and treatment responses.

Cell Differentiation↗
PubMed1999

Somatization and depression among former Soviet immigrants.

This study investigated the prevalence of pure and overlapping forms of somatization and depression in a sample of former Soviet immigrants and whether pure somatization or pure depression could be differentiated using the study variables. Study respondents completed a demographic questionnaire, the Demands of Immigration Scale, and the Symptom Checklist 90R. Respondents were classified as (a) neither depressed nor somatic, (b) only somatic, (c) only depressed, or (d) both depressed and somatic. Univariate analyses and logistical regression were used to compare these four groups and to predict the likelihood of being only depressed or only somatic. The four groups differed in terms of immigration demands, age, education, employment, and years in the U.S. A logistic regression analysis was able to classify 75% of the participants as only somatic or only depressed on the basis of certain demographic characteristics. Age, being unemployed and not looking for work, and not having a college education increased the risk of being somatic rather than depressed.

Adult↗
PubMed2001

Specific IgE antibody responses to somatic and excretory-secretory antigens of third stage G. spinigerum larvae in human gnathostomiasis.

Specific IgE antibody levels in the serum of patients with proven gnathostomiasis and in those with intermittent cutaneous migratory swelling (CMS) were determined by the enzyme-linked immunosorbent assay (ELISA) using somatic extract and excretory-secretory (ES) products of Gnathostoma spinigerum infective larvae as antigens. The third stage larval used were obtained from naturally infected eels. There was an increase in specific IgE antibody to both antigens in these patients. The mean levels of these specific IgE antibodies were significantly higher than that of the healthy control (P<0.01). Comparison between using somatic extract and ES products in the test showed, a positive result in the group of suspected patients with gnathostomiasis or CMS was significantly higher when using ES products (81.81%) than somatic extract (59.09%) as the antigens (P<0.05). However, both somatic and ES antigens cross-reacted with other parasitic sera. The overall sensitivity of the ELISA for these IgE antibodies detection were 71.87 per cent and 87.50 per cent with somatic and ES antigens, respectively. The specificity was 57.53 per cent when somatic antigen was used and increased to 69.86 per cent when ES antigen was used. The positive and negative predictive values of the test were 42.59 per cent and 82.35 per cent by using somatic antigen. Both of these values, were also increased to 56.00 per cent and 92.72 per cent by using the ES antigen. It is obvious that more potential components may be present in ES products than those in the somatic extract. The ES antigen may have to be further purified and may be suitable for evaluation of the effectiveness of chemotherapy. As such, the antibody responses to secreted products are more closely related to active infection than the anti-whole worm antibody that may persist following the death of the parasites. However, in this disease, the effect of the IgE antibody on its pathophysiology it is still not known.

Animals↗
PubMed1991

Factors leading to the reporting of 'functional' somatic symptoms by general practice attenders.

The aim of this study was to examine the prevalence of 'functional' somatic symptoms in general practice and the factors associated with reporting these symptoms. During a one month period, all attenders aged 16 years and over at a general practice near Leeds were screened for functional somatic symptoms using the Bradford somatic inventory. The general practitioner recorded the patients' personal data and diagnostic assessment. Data were analysed from 670 Europid patients who completed the Bradford somatic inventory at their first attendance during the month. Higher mean numbers of functional somatic symptoms were found in patients with psychiatric and functional syndromes than in patients with organic illness or in well patients. The symptom score on the Bradford somatic inventory was significantly related to five factors: current anxious mood, current depressed mood, sex, chronic physical illness in a parent and a history of depressive illness. Using multiple linear regression analysis, all five factors were found to be independent predictors of symptom scores on the Bradford somatic inventory. This study highlights the multifactorial aetiology of functional somatic symptoms reported by general practice attenders.

Adult↗
PubMed1986

Neurotic depression accompanied by somatic symptoms: a double-blind comparison of flupenthixol and diazepam in general practice.

A total of 192 patients suffering from mild to moderate depression, with or without anxiety, accompanied by one or more specific somatic symptoms, was entered into a double-blind, multi-centre trial to compare flupenthixol and diazepam as treatments for psychosomatic syndromes in general practice. Each patient was treated for 4 weeks and assessed after 1, 2 and 4 weeks on the Hamilton Depression Scale, with visual analogue scales of depression and somatic symptoms, by global assessments (psychological and somatic symptoms) and on a side-effects scale. The principal somatic symptoms were tension headache (69 patients), epigastric discomfort (59 patients), chest pain (39 patients) and backache (25 patients). There were 9 drop-outs (2 on flupenthixol and 7 on diazepam), of whom 5 (2 on flupenthixol and 3 on diazepam) who were treated for at least 2 weeks were included in the analysis of results. All patients received 1 tablet a day (0.5 mg flupenthixol or 2.5 mg diazepam) for the first week. Thereafter, all except 5 patients (3 on flupenthixol and 2 on diazepam) had their dose doubled for the remaining 3 weeks of study. Both drugs were effective in producing consistent improvement in all four somatic symptom groups in terms of both depression and somatic symptoms over the 4 weeks of study. There was a trend throughout in favour of flupenthixol as the more therapeutically effective. Flupenthixol was significantly more effective in relieving depressive symptoms and somatic symptoms in all four somatic symptom groups considered together. It was also superior to diazepam as measured by its effect on the depression sub-scales, anxiety, agitated depression, retarded depression and melancholia. Both drugs were well tolerated, although diazepam-treated patients showed a moderate increase in side-effects scores initially, while the scores in patients treated with flupenthixol decreased consistently over all 4 weeks of the trial. It is concluded from this study that flupenthixol has an important place in the management of patients with psychosomatic illness.

Adult↗
PubMed1981

Changes in somatic cell structure during senescence of Volvox carteri.

Senescence of the terminally differentiated somatic cells of the green alga, Volvox carteri f. weismannia, was investigated by light, fluorescence, and electron microscopy. Viability of the somatic cell population, as determined by trypan blue or erythrosin B exclusion, showed a sharp reduction beginning 144 h after the somatic cells had lost the ability to divide. This increased mortality rate was correlated at the light microscopic level with a retraction of the somatic cell cytoplasm, a reduction in chloroplast autofluorescence (and total chlorophyll content), and a decline in the number of vacuoles which could be localized with 9-aminoacridine fluorescence microscopy. Nuclear fluorescence with acridine orange remained unaffected during this time. Lipid bodies increased in older cells, and total lipid analysis showed a sharp increase beginning 96 h after the somatic cells had stopped dividing. Electron microscopic comparison between young (48--72 h) and old (168 h) somatic cells showed a disorganization of chloroplast structure, a decline in the number of cytoplasmic ribosomes, and, substantiating the light microscopy, and accumulation of lipid bodies in the cytoplasm of the older cells. The results demonstrate progressive changes in somatic cell structure with age and are suggestive of cells under nutrient stress even though they are in nutrient medium. Therefore senescence and death of the V. carteri somatic cells may be caused, in part, by an inability to take up or utilize nutrients present in the culture medium.

Aging↗
PubMed1994

Characteristics of somatic mutation of the adenomatous polyposis coli gene in colorectal tumors.

Mutation of the adenomatous polyposis coli (APC) gene was analyzed in 500 colorectal tumors from 70 familial adenomatous polyposis (FAP) and 102 non-FAP patients and in normal tissues from 119 FAP patients, using polymerase chain reaction-single-strand conformation polymorphism and direct sequencing methods. These tumors were histopathologically diagnosed. Sixty-eight germ line mutations (62% deletion, 9% insertion, and 29% single-base substitution) and 241 somatic mutations (56% deletion, 12% insertion, and 32% single-base substitution) were detected. All mutations formed stop codons resulting in truncated APC proteins, except for one germ line mutation. Differences were found between somatic and germ line mutations, including 3 new hot spots of mutation at codons 1378, 1450, and 1487-1490, which frequently occurred in somatic mutations but not in germ lines. The frequency of mutation in each histopathological type of FAP tumor was 53% in moderate adenoma, 64% in severe adenoma, 52% in intramucosal carcinoma, and 33% in invasive carcinoma, whereas the loss of heterozygosity including the APC gene increased with development to each histopathological type. A similar tendency was observed in non-FAP tumors. Additionally, we found 10 FAP tumors that had both somatic mutation and loss of heterozygosity. These tumors were assumed to have developed from moderate adenomas with germ line and somatic mutations, followed by deletion of the allele with germ line mutation. These results suggest that inactivation of the APC gene by two mutations is involved in the development of moderate adenoma, and loss of heterozygosity of the APC gene is associated with further development to carcinoma. It was also observed that the distribution of 75 somatic mutations from one FAP patient on the APC sequence was similar to the distribution of 159 somatic mutations from 83 patients with FAP and non-FAP, which suggests that the position of somatic mutation is mostly due to the APC sequence itself.

Adenoma↗
PubMed1997

[Somatic illness in psychiatric patients].

Psychiatric patients are a vulnerable group in society and have been shown to suffer from a wide range of somatic diseases when admitted to the psychiatric department. During a three month period we examined 174 newly admitted psychiatric patients with the purpose of investigating 1) the frequency of somatic illness, 2) the value of routine blood tests as a screening tool for somatic illness and 3) a possible causality between somatic disease and psychiatric illness. Fifty percent of the patients suffered from a somatic disease and 31% of the patients had a previously undiagnosed disease. The somatic disease was found to be the main cause of admission in 16% of the patients. Older patients and patients with alcohol abuse were found to have the highest prevalence of somatic disease. In conclusion, we found no indication for a screening programme of blood tests, but recommend that selected blood tests based on the clinical examination and history of the individual patient should be taken. Psychiatric patients have a high prevalence of somatic disease, and it is important to direct clinical attention towards this when giving care to psychiatric patients.

Alcoholism↗
PubMed2001

Causal attributions for somatic sensations in patients with chronic fatigue syndrome and their partners.

BACKGROUND: Patients with chronic fatigue syndrome (CFS) often make somatic attributions for their illness which has been associated with poor outcome. A tendency to make somatic attributions in general may be a vulnerability factor for the development of CFS. METHODS: This cross-sectional study based on self-report questionnaire data aimed to investigate the type of attributions for symptoms made by patients with CFS and to compare this to attributions made by their partners. It was hypothesized that patients with CFS would make more somatic attributions for their own symptoms than control subjects and that partners of patients with CFS would make more somatic attributions for their ill relative's symptoms but would be similar to controls regarding their own symptoms. Fifty patients with CFS were compared to 50 controls from a fracture clinic in the same hospital and 46 relatives living with the patients with CFS. A modified Symptom Interpretation Questionnaire was used to assess causal attributions. RESULTS: CFS patients were more likely to make somatic attributions for their symptoms. The relatives of patients with CFS made significantly more somatic attributions for symptoms in their ill relative. However, they were like the fracture clinic controls in terms of making predominantly normalizing attributions for their own symptoms. CONCLUSIONS: The data support modification of existing cognitive behavioural treatments for CFS to investigate whether addressing partners' attributions for patients' symptoms improves recovery in the patient. Furthermore, a tendency to make somatic attributions for symptoms may be a vulnerability factor for the development of CFS.

Adolescent↗
PubMed1998

Somatization in young versus older female panic disorder patients.

BACKGROUND AND RATIONALE: Studies in younger patients with panic disorder suggest greater somatization compared to similarly aged normal controls. Thus, we compared the degree of somatization in young versus older female patients with panic disorder to ascertain whether similarly high levels of somatization exist in older panic disorder patients. METHOD: Community-dwelling subjects were recruited for clinical trials for panic disorder and met Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R) criteria for panic disorder as a primary diagnosis. Our sample (N = 64) contained 42 younger females (< 55 years of age; age range 21-54, mean age 34.6) who were compared to 22 older females (> or = 55 years of age; age range 55-73, mean age 60.8). Subjects were evaluated at baseline using the Self-Report Inventory for Somatic Symptoms (SISS). Statistical analysis of total somatization disorder scores (TSDS) was accomplished by t-tests for independent groups. RESULTS: Older patients showed statistically significantly higher total somatization disorder scores (TSDS) (X = 11.54, SD = 7.45) than did younger patients (X = 8.07, SD = 4.77; t(62) = 2.27, p = < 0.05). CONCLUSION: Our results are suggestive of a higher degree of somatization in older compared to younger female panic disorder patients.

Adult↗
PubMed2001

Somatic INK4a-ARF locus mutations: a significant mechanism of gene inactivation in squamous cell carcinomas of the head and neck.

The INK4a-ARF locus is located on human chromosome 9p21 and is known to encode two functionally distinct tumor-suppressor genes. The p16(INK4a) (p16) tumor-suppressor gene product is a negative regulator of cyclin-dependent kinases 4 and 6, which in turn positively regulate progression of mammalian cells through the cell cycle. The p14(ARF) tumor-suppressor gene product specifically interacts with human double minute 2, leading to the subsequent stabilization of p53 and G(1) arrest. Previous investigations analyzing the p16 gene in squamous cell carcinomas of the head and neck (SCCHNs) have suggested the predominate inactivating events to be homozygous gene deletions and hypermethylation of the p16 promoter. Somatic mutational inactivation of p16 has been reported to be low (0-10%, with a combined incidence of 25 of 279, or 9%) and to play only a minor role in the development of SCCHN. The present study examined whether this particular mechanism of INK4a/ARF inactivation, specifically somatic mutation, has been underestimated in SCCHN by determining the mutational status of the p16 and p14(ARF) genes in 100 primary SCCHNs with the use of polymerase chain reaction technology and a highly sensitive, nonradioactive modification of single-stranded conformational polymorphism (SSCP) analysis termed "cold" SSCP. Exons 1alpha, 1beta, and 2 of INK4a/ARF were amplified using intron-based primers or a combination of intron- and exon-based primers. A total of 27 SCCHNs (27%) exhibited sequence alterations in this locus, 22 (22%) of which were somatic sequence alterations and five (5%) of which were a single polymorphism in codon 148. Of the 22 somatic alterations, 20 (91%) directly or indirectly involved exon 2, and two (9%) were located within exon 1alpha. No mutations were found in exon 1beta. All 22 somatic mutations would be expected to yield altered p16 proteins, but only 15 of them should affect p14(ARF) proteins. Specific somatic alterations included microdeletions or insertions (nine of 22, 41%), a microrearrangement (one of 22, 5%), and single nucleotide substitutions (12 of 22, 56%). In addition, we analyzed the functional characteristics of seven unique mutant p16 proteins identified in this study by assessing their ability to inhibit cyclin-dependent kinase 4 activity. Six of the seven mutant proteins tested exhibited reduced function compared with wild-type p16, ranging from minor decreases of function (twofold to eightfold) in four samples to total loss of function (29- to 38-fold decrease) in two other samples. Overall, somatic mutation of the INK4a/ARF tumor suppressor locus, resulting in functionally deficient p16 and possibly p14(ARF) proteins, seems to be a prevalent event in the development of SCCHN. Mol. Carcinog. 30:26-36, 2001.

Base Sequence↗
PubMed1994

Ultrastructural plasticity of the dentate gyrus granule cells following recurrent limbic seizures: II. Alterations in somatic synapses.

Hilus lesion-induced recurrent limbic seizures cause a dramatic increase in the numbers of somatic spines on dentate gyrus granule cells in the adult rat. Somatic spines are maximally increased 3 h after the initiation of seizures at which time many of these spines form synapses. The present quantitative electron microscopic study assessed the numbers and types of synapses present on the granule cell perikarya and somatic spines of control and experimental seizure rats with the goal of determining if newly elaborated somatic spines arise at the site of pre-existing synapses or are associated with new innervation. Experimental rats were sacrificed 5 h after hilar lesion placement (or 3 h after seizure onset). In both control and hilus-lesioned (HL) rats, 15-20% of the somatic spines could be seen to form synaptic contacts within a single plane of section; these synapses were almost exclusively of the asymmetric type. With the increased incidence of spines in experimental-seizure rats, there was a 6.25-fold greater number of spine synapses in HL versus control rats. There was, in addition, a 60% decrease in the number of asymmetric synapses occurring directly on the granule cell perikarya but no change in the total (spine plus somatic) number of asymmetric synapses. Although few asymmetric synapses were associated with spines in control tissue, 60-70% of asymmetric synapses were associated with spines in experimental-seizure tissue. In addition, in hilus lesion rats symmetric somatic synapses were increased by 20% on cells in deep stratum granulosum resulting in a dissolution of the superficial-to-deep innervation gradient present in the untreated rat. These findings support the conclusion that spines induced by seizure activity form at the site of pre-existing asymmetric synapses on the granule cells and demonstrate that brief seizure episodes can rapidly induce marked changes in innervation patterns in the adult brain.

Animals↗