Lime Rates and Sources

A lime rate and source study was implemented in 1996 at the Armstrong Research Farm to observe liming practices in no-till situations. The addition of lime to raise pH to 6.5 for row crops has been a long-standing recommendation. Those recommendations have included thorough mixing of the lime material with the soil which might be expected from normal tillage practices. This study will measure any corn and soybean yield changes, and the possible stratification of soil pH over time using no-till production practices

The 2HA line of Medicago truncatula has characteristics of an epigenetic mutant that is weakly ethylene insensitive

BACKGROUND The Medicago truncatula 2HA seed line is highly embryogenic while the parental line Jemalong rarely produces embryos. The 2HA line was developed from one of the rare Jemalong regenerates and this method for obtaining a highly regenerable genotype in M. truncatula is readily reproducible suggesting an epigenetic mechanism. Microarray transcriptomic analysis showed down regulation of an ETHYLENE INSENSITIVE 3-like gene in 2HA callus which provided an approach to investigating epigenetic regulation of genes related to ethylene signalling and the 2HA phenotype. Ethylene is involved in many developmental processes including somatic embryogenesis (SE) and is associated with stress responses. RESULTS Microarray transcriptomic analysis showed a significant number of up-regulated transcripts in 2HA tissue culture, including nodule and embryo specific genes and transposon-like genes, while only a few genes were down-regulated, including an EIN3-like gene we called MtEIL1. This reduced expression was associated with ethylene insensitivity of 2HA plants that was further investigated. The weak ethylene insensitivity affected root and nodule development. Sequencing of MtEIL1 found no difference between 2HA and wild-type plants. DNA methylation analysis of MtEIL1 revealed significant difference between 2HA and wild-type plants. Tiling arrays demonstrated an elevated level of miRNA in 2HA plants that hybridised to the antisense strand of the MtEIL1 gene. AFLP-like methylation profiling revealed more differences in DNA methylation between 2HA and wild-type. Segregation analysis demonstrated the recessive nature of the eil1 phenotype and the dominant nature of the SE trait. CONCLUSIONS We have demonstrated that EIL1 of Medicago truncatula (MtEIL1) is epigenetically silenced in the 2HA seed line. The possible cause is an elevated level of miRNA that targets its 3'UTR and is also associated with DNA methylation of MtEIL1. Down regulation of MtEIL1 makes it possible to form nodules in the presence of ethylene and affects root growth under normal conditions. Segregation analysis showed no association between MtEIL1 expression and SE in culture but the role and mechanism of ethylene signalling in the process of plant regeneration through SE requires further investigation. The work also suggests that epigenetic changes to a particular gene induced in culture can be fixed in regenerated plants.This work was funded by the Australian Research Council (CEO348212) through the ARC Centre of Excellence for Integrative Legume Research (CILR)

DEXAMETHASONE SUPPRESSION TEST IN DEPRESSION

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23089/1/0000006.pd

Endocrine control of psychomotor activity in the rat: Effects of chronic dexamethasone upon general activity

In order to expand previous studies on endocrine control of activity the synthetic glucocorticoid, dexamethasone, was introduced into the water supply of adult male Sprague-Dawley rats. The drug produced marked reductions in daily activity patterns which were accompanied by a redistribution of circadian patterns. These changes were reversible, in part, upon discontinuation. Controls for weight loss indicated this was probably not a contributing factor. The present results point to an influence of the hypothalamo-pituitary-adrenal axis upon long-term general activity patterns.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22699/1/0000253.pd

The psychobiology of premenstrual dysphoria: review of theories and treatments

(1) Premenstrual mood changes such as depression, elation, anxiety, hostility and irritability are a common cause of disability in women. (2) The nature of the disorder, the clinical dimensions, the incidence, the psychological and psychosocial theories are reviewed. (3) A long list of treatments recommended over the years is also reviewed and discussed, illustrating the ambiguity and uncertainty in this area. (4) The relationship to other periodic functional conditions, especially manic-depressive illness is discussed with particular emphasis on predictive studies. (5) The psychoneuroendocrine mechanisms possibly involved in these premenstrual conditions are reexamined. A specific role for prolactin in the etiology of these premenstrual dysphoric states is suggested.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23045/1/0000617.pd

The psychobiology of premenstrual dysphoria: The role of prolactin

(1) The evidence for a role of prolactin in the premenstrual syndrome is discussed in this review. (2) The timing of the onset and offset of both physical and psychological dysphoric symptoms corresponds with the luteal elevation and menstrual decrease of serum prolactin levels. (3) Women with premenstrual symptoms have been shown to have high prolactin levels throughout the menstrual cycle and especially in the premenstruum. (4) Suppression of prolactin secretion with bromocriptine is reported to be effective in preventing both physical and psychological premenstrual symptoms. (5) The mode of action of bromocriptine requires further study to exclude possible direct central nervous system effects of the drug, independent of its prolactin-suppressing action. (6) Indirect evidence for a role of prolactin in the premenstrual syndrome comes from (a) the actions of prolactin in causing renal retention of water, sodium and potassium; (b) the interactions of prolactin with lithium (which is reported to relieve premenstrual symptoms in some patients); some of the other reported treatments also may suppress prolactin secretion or antagonize its peripheral effects. (7) Prolactin may interact with the ovarian hormones to cause specific types of dysphoric symptoms. High prolactin levels associated with low estrogen levels may cause depressive symptoms. High prolactin levels associated with low progesterone levels may cause symptoms of anxiety or irritable hostility. (8) Interactions of prolactin with the ovarian hormones may also help to account for some related clinical states--mid-cycle mood elevations, elation in late pregnancy, postpartum depression and dysphoric menopausal symptoms.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22717/1/0000272.pd

Intracranial reward after Lilly 110140 (fluoxetine HCl): Evidence for an inhibitory role for serotonin

The 5-hydroxytryptamine (5-HT, serotonin) specific presynaptic reuptake inhibitor Lilly 110140 (fluoxetine hydrochloride) was injected systemically in rats trained to bar-press for rewarding stimulation to the caudal portion ofthe medial forebrain bundle. Rates of self stimulation were reduced in proportion to drug dosage, and these reductions were partially reversible by methysergide. These findings are consistent with previous reports suggesting an inhibitory role for 5-HT in self stimulation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46398/1/213_2004_Article_BF00431739.pd

Separation of subtypes of depression using discriminant analysis : Separation of bipolar endogenous depression from nonendogenous ("Neurotic") depression

We derived a discriminant function separating patients with bipolar endogenous depression ("melancholia") from patients with nonendogenous ("neurotic") depression, and showed that the difference between the groups was not one of overall severity of illness alone. The discriminant function (DF) included 5 clinical items.We reduced the DF to a discriminant index (DI) with integral item weights, and trichotomized the DI scores into two definite classifications and an intermediate, uncertain classification. We cross-validated this DI in a separate group of patients, and found no decrease in the accuracy of classification on cross-validation. Thirty-three of 41 (80%) of the patients in the cross-validation group were classified by the DI; 26 of 33 (79%) correctly.We also validated the DI classification against an external, biological marker, the dexamethasone suppression test (DST). The DI predicted the DST result with the same accuracy as the clinical diagnoses did, supporting the validity of the DI.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25226/1/0000667.pd

Effects of chronic lithium and rubidium administration upon experimentally induced conflict behavior

1. 1. Chronic treatment of rats with lithium chloride produced a significant reduction of shock induced suppression of feeding behavior (passive avoidance) in the rat.2. 2. Rubidium chloride, on the other hand, caused additional suppression of feeding under the same conditions.3. 3. These results suggest that two drugs may affect anxiety processes in opposite directions, and this may be of clinical significance.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23043/1/0000615.pd

Inhibition of phenylethanolamine-N-methyltransferase and brain-stimulated reward

Three centrally active inhibitors of phenylethanolamine-N-methyl transferase (PNMT; E.C.2.1.1.28), the terminal enzyme for epinephrine biosynthesis in the brain, produced dose-related decreases in rates of responding for rewarding brain stimulation in adult male rats. Decreases occurred at dosages that did not produce measurable neurologic impairment. This suggests a possible role for central epinephrine-containing neurons in the maintenance of reward-mediated behaviors.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46401/1/213_2004_Article_BF00426955.pd