| 1. |
- Engel, Jörgen, 1942, et al.
(author)
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Neonatal herpes simplex virus type 1 brain infection affects the development of sensorimotor gating in rats.
- 2000
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In: Brain research. - 0006-8993. ; 863:1-2, s. 233-40
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Journal article (peer-reviewed)abstract
- The effect of neonatal brain infection of herpes simplex virus type 1 (HSV-1) on the development of sensorimotor function in the rat was investigated using an acoustic startle paradigm. Intracerebral inoculation of HSV-1 at day 2 after birth, but not at day 4, caused a significant delay in the development of prepulse inhibition of acoustic startle. A decrease in prepulse inhibition was shown at 37, 46 and 58 days of age in these rats compared to control rats. No evidence was obtained for other behavioural dysfunctions such as differences in sensorimotor reactivity, sensorimotor response habituation, spontaneous locomotor activity, rearing activity or stereotyped behaviour. Prepulse inhibition of acoustic startle is an accepted model of sensorimotor gating in the CNS, a function which has been shown diminished in schizophrenic persons. The present results suggest that early viral infections during a neurone-susceptible period may contribute to the development of this deficit.
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| 2. |
- Lindquist, Catarina, et al.
(author)
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Extrasynaptic GABA(A) channels activated by THIP are modulated by diazepam in CA1 pyramidal neurons in the rat brain hippocampal slice
- 2003
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In: Molecular and Cellular Neuroscience. - 1044-7431 .- 1095-9327. ; 24:1, s. 250-257
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Journal article (peer-reviewed)abstract
- Single-channel currents were activated by THIP (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol) in cell-attached patches on CA1 pyramidal neurons in the rat hippocampal slice preparation. THIP activated GABA(A) channels after a delay that was concentration-dependent and decreased by 1 muM diazepam. The currents showed outward rectification. Channels activated at depolarized 40 mV relative to the chloride reversal potential had low conductance (<40 pS) but the conductance increased with time, resulting in high-conductance channels (>40 pS). The average maximal-channel conductances for 2 and 100 muM THIP were 59 and 62 pS (-Vp = 40 mV), respectively, whereas in 2 muM THIP plus 1 muM diazepam, it was 71 pS. The results show that in hippocampal neurons THIP activates channels with characteristics similar to those of channels activated by low concentrations (0.5-5 AM) of GABA. The increase in the inhibitory conductance with membrane depolarization permits gradation of the shunt pathway relative to the level of the excitatory input. (C) 2003 Elsevier Science (USA). All rights reserved.
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| 3. |
- Birnir, Bryndis, et al.
(author)
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Bicuculline, pentobarbital and diazepam modulate spontaneous GABA(A) channels in rat hippocampal neurons
- 2000
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In: British Journal of Pharmacology. - : Wiley. - 1476-5381 .- 0007-1188. ; 131:4, s. 695-704
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Journal article (peer-reviewed)abstract
- Spontaneously opening, chloride-selective channels that showed outward rectification were recorded in ripped-off patches from rat cultured hippocampal neurons and in cell-attached patches from rat hippocampal CA1 pyramidal neurons in slices. In both preparations, channels had multiple conductance states and the most common single-channel conductance varied. In the outside-out patches it ranged from 12 to 70 pS (Vp=40 mV) whereas in the cell-attached patches it ranged from 56 to 85 pS (-Vp=80 mV). Application of GABA to a patch showing spontaneous channel activity evoked a rapid, synchronous activation of channels. During prolonged exposure to either 5 or 100 microM GABA, the open probability of channels decreased. Application of GABA appeared to have no immediate effect on single-channel conductance. Exposure of the patches to 100 microM bicuculline caused a gradual decrease on the single-channel conductance of the spontaneous channels. The time for complete inhibition to take place was slower in the outside-out than in the cell-attached patches. Application of 100 microM pentobarbital or 1 microM diazepam caused 2 - 4 fold increase in the maximum channel conductance of low conductance (<40 pS) spontaneously active channels. The observation of spontaneously opening GABA(A) channels in cell-attached patches on neurons in slices suggests that they may have a role in neurons in vivo and could be an important site of action for some drugs such as benzodiazepines, barbiturates and general anaesthetics.
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| 4. |
- Cheng, Fang, et al.
(author)
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Differences in the uptake and nuclear localization of anti-proliferative heparan sulfate between human lung fibroblasts and human lung carcinoma cells
- 2001
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In: Journal of Cellular Biochemistry. - : Wiley. - 0730-2312 .- 1097-4644. ; 83:4, s. 597-606
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Journal article (peer-reviewed)abstract
- Heparan sulfate inhibits the proliferation of normal human lung fibroblasts (HFL-1) but not of a human lung carcinoma cell-line (A549). in this study we investigated possible mechanisms and structural requirements by which anti proliferative heparan sulfates exerts its effects on binding, uptake and subcellular localisation. Both HFL-1 and A549 cells were incubated with I-125- or rhodamine-labeled L-iduronate-rich antiproliferative heparan sulfate species as well as L-iduronate-poor inactive ones. The anti proliferative heparan sulfate was bound to the cell surface on both HFL-1 and A549 cells, but to a lesser extent and with less affinity to A549 cells. Both cell types bound the anti proliferative heparan sulfate with one high- and with one low affinity site. The L-iduronate-poor heparan sulfate bound to a lesser extent and with less affinity to both cell types compared to the anti proliferative heparan sulfate. The antiproliferative heparan sulfate accumulated in the cytoplasm of HFL-1 cells after 24 h incubation, but after 72 h it was found evenly distributed in the nucleus. The time-scale for anti proliferative activity correlated with nuclear localization. In contrast, in A549 cells it was only found near the nuclear membrane. The inactive heparan sulfate was taken up in considerably smaller amounts compared to the antiproliferative heparan sulfate and could not be detected in the nucleus of either HFL-1 or A549 cells. Our data suggest that the anti proliferative activity of L-iduronate-rich heparan sulfate on normal fibroblasts may be due to direct effects on nuclear processes, such as gene transcription.
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| 5. |
- Eghbali, M, et al.
(author)
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Pentobarbital modulates gamma-aminobutyric acid-activated single-channel conductance in rat cultured hippocampal neurons.
- 2000
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In: Molecular Pharmacology. - 0026-895X .- 1521-0111. ; 58:3, s. 463-9
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Journal article (peer-reviewed)abstract
- We examined the effect of a range of pentobarbital concentrations on 0.5 microM gamma-aminobutyric acid (GABA)-activated channels (10 +/- 1 pS) in inside-out or outside-out patches from rat cultured hippocampal neurons. The conductance increased from 12 +/- 4 to 62 +/- 9 pS as the pentobarbital concentration was raised from 10 to 500 microM and the data could be fitted by a Hill-type equation. At 100 microM pentobarbital plus 0.5 microM GABA, the conductance seemed to reach a plateau. The pentobarbital EC(50)(0.5 microM GABA) value was 22 +/- 4 microM and n was 1.9 +/- 0.5. In 1 mM pentobarbital plus 0.5 microM GABA, the single-channel conductance decreased to 34 +/- 8 pS. This apparent inhibition of channel conductance was relieved by 1 microM diazepam. The channel conductance was 64 +/- 6 pS in the presence of all three drugs. The channels were open more in the presence of both GABA and pentobarbital than in the presence of either drug alone. Pentobarbital alone (100 microM) activated channels with conductance (30 +/- 2 pS) and kinetic properties distinct from those activated by either GABA alone or GABA plus pentobarbital. Whether pentobarbital induces new conformations or promotes conformations observed in the presence of GABA alone cannot be determined from our study, but the results clearly show that it is the combination of drugs present that determines the single-channel conductance and the kinetic properties of the receptors.
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| 6. |
- Jensen, Jimmy, et al.
(author)
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Neurocognitive and psychopathological correlates of self-monitoring ability in schizophrenia.
- 2004
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In: European Archives of Psychiatry and Clinical Neuroscience. - : Springer. - 0940-1334 .- 1433-8491. ; 254:5, s. 312-317
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Journal article (peer-reviewed)abstract
- In a previous study reported by our group one salient finding was that many patients with schizophrenia appeared to be unable to judge their own quality of life (QoL) and that this inability was associated with negative symptoms. The association between negative symptoms, poor self-monitoring capacity and lack of insight might be explained by a common underlying factor, i.e. neurocognitive impairment. Fifty schizophrenic patients were examined by symptom ratings and a comprehensive neuropsychological test battery. The cognitive performance of the patients was very poor. The major findings of the present study were the association between clinically rated Lack of judgement (PANSS G12) and 1) a set of standard performance and executive indices of the computerised tests, and 2) difference scores between objective performance/strategies and self-ratings of the same attributes. There appears to be a substantial contribution of cognitive and executive problems to the poor judgement and lack of insight of schizophrenic patients, and these problems can to some extent be assessed objectively.
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| 7. |
- Norlin, Marianne, et al.
(author)
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Vomeronasal Phenotype and Behavioral Alterations in Gαi2 Mutant Mice
- 2003
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In: Current Biology. - : Cell Press. - 0960-9822 .- 1879-0445. ; 13:14, s. 1214-1219
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Journal article (peer-reviewed)abstract
- Several social and reproductive behaviors are under the influence of the vomeronasal (VN) organ; VN neurons detect odorous molecules emitted by individuals of the same species. There are two types of VN neurons, and these differ in their expression of chemosensory receptors and G protein subunits. The significance of this dichotomy is largely unknown. VN neurons express high levels of either G alpha i2 or G alpha o. A mouse line carrying a targeted disruption of the G alpha i2 gene offered the opportunity for studying the effects of a lack of receptor signaling through the heterotrimeric Gi2 protein in one VN cell type. As a consequence of this deficiency, the number of VN neurons that normally express G alpha i2 is decreased by half. These residual neurons are defective in eliciting a response in their target neurons in the accessory olfactory bulb. Moreover, G alpha i2 mutant mice show alterations in behaviors for which an intact VN organ is known to be important. Display of maternal aggressive behavior is severely blunted, and male mice show significantly less aggression toward an intruder. However, male mice show unaltered sexual-partner preference. This suggests that the two types of VN neurons may have separate functions in mediating behavioral changes in response to chemosensory information.
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| 8. |
- Ohlsson, Bodil, et al.
(author)
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The method of administration of cholecystokinin determines the effects evoked in the pancreas
- 2001
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In: Pancreas. - 0885-3177. ; 23:1, s. 94-101
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Journal article (peer-reviewed)abstract
- Earlier studies have shown different effects on cell proliferation and weight characteristics by sulfated cholecystokinin-8 (CCK-8S) in the rat pancreas when the peptide has been administered continuously rather than intermittently. The aim of this study was as follows: (i) to compare the effect of continuous infusion and of intermittent injections of CCK-8S on cell proliferation, weight gain, and induction of apoptosis and (ii) to examine the effect of injections of CCK-8S on CCK-A receptor gene expression in the rat pancreas. Male Sprague-Dawley rats had subcutaneous continuous infusion of CCK-8S in a dose of 5 microg/kg/h or 1% bovine serum albumin (BSA) (vehicle) by implanted osmotic minipumps. The rats were killed after 4 days. Other rats were either injected subcutaneously only once or injected twice daily for 3 days with either 6 microg of CCK dissolved in 0.5 mL BSA or 0.5 mL BSA alone. The rats were killed 1, 3, 6, and 12 hours after the last injection. One hour before death they received 5-bromo-2-deoxyuridine (BrdU) intraperitoneally to localize and quantitate the cell proliferation. Plasma was collected for analysis of CCK. The pancreas was dissected and immunohistochemistry was performed for analysis of the expression of the apoptosis promoting protein bax and the apoptosis inhibiting protein bcl-2, and for BrdU and CCK-A receptor localization. In situ hybridization (ISH) was used for examination and semiquantification of CCK-A receptor mRNA expression. Continuous infusion of CCK-8S led to a sixfold increase in plasma CCK and a 40% increase in pancreatic weight without any effect on BrdU labeling. Immunohistochemistry revealed decreased tissue expression of bax but unaffected expression of bcl-2. Intermittent injections of CCK-8S led to hyper-CCK-emia with increased incorporation of BrdU, indicating increased cell proliferation but no increase in pancreatic weight. Immunohistochemistry showed increased expression of bax, whereas bcl-2 remained unchanged. Immunofluorescence and ISH for the CCK-A receptor and its gene expression, respectively, showed a lowest intensity at 3 hours after CCK-8S injections. The results indicate that decreased apoptosis could explain the increased pancreatic weight during continuous infusion of CCK-8S. An increased apoptosis could explain the lack of pancreatic weight gain upon intermittent injections of CCK-8S despite the stimulation of cell proliferation. Injections of CCK-8S only transiently decreased the tissue levels of its receptor.
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