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M Sandstrom

Publications and source records attributed to M Sandstrom.

6 recordsLinked to original sources
PubMed1998

c-fos gene expression is induced in a subpopulation of striatal neurons following a single administration of a dopamine D1-receptor agonist in adult rats lesioned with 6-OHDA as neonates.

The effects of the dopamine D1 receptor agonist, SKF-38393, on the levels of mRNAs encoding for the proto-oncogene c-fos and the GABA-synthesizing enzyme glutamate decarboxylase (GAD65) were measured by in situ hybridization histochemistry in the striatum of adult rats depleted of dopamine as neonates. c-fos mRNA levels exhibited a prominent increase following the acute systemic administration of SKF-38393 in dopamine-depleted but not in normal rats. Double-labeling in situ hybridization histochemistry using a radioactive c-fos probe and a digoxigenin-labeled preproenkephalin (PPE) cRNA probe indicated that c-fos mRNA levels were increased by SKF-38393 exclusively in a subpopulation of PPE-unlabeled neurons. Dopamine-depleted rats exhibited an increase in GAD65 mRNA levels relative to control rats. Acute administration of SKF-38393 did not alter GAD65 mRNA levels in control or in dopamine-depleted rats. Our results demonstrate that an acute administration of a D1-receptor agonist induces c-fos but not GAD65 gene expression in a subpopulation of presumed striato-nigral/entopeduncular neurons. They also suggest that the D1-dependent behavioral plasticity exhibited by adult rats depleted of dopamine as neonates is not the result of an altered activation of the two subpopulations of striatal efferent neurons.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1997

Lack of effects of lesions of the dorsal noradrenergic bundle on behavioral vigilance.

The effects of 6-hydroxydopamine (6-OHDA)-induced lesions of the dorsal noradrenergic bundle (DNB) were assessed in animals trained in a task designed to measure sustained attention, or vigilance. Infusions of 6-OHDA reduced frontal cortical noradrenaline contents but did not significantly affect striatal and hypothalamic noradrenaline contents. The performance of lesioned animals did not differ significantly from sham-lesioned controls. The performance of both the lesioned and sham-lesioned animals was impaired by the presentation of a visual distractor and by a decrease in the probability for a signal. The results from this study largely coincide with the results from previous studies on the effects of noradrenergic lesions on various aspects of attention. In contrast to the attentional functions assessed in this experiment, the ability to detect and select stimuli that are associated with activation of sympathetic functions is hypothesized to be sensitive to the effects of DNB lesions.

Afferent Pathways↗
PubMed1976

Morphological changes in corneal endothelial cells after penetrating keratoplasty.

Fifteen patients who had had a successful penetrating keratoplasty were photographed with the clinical specular microscope and the resulting endothelial photomicrographs were analyzed. The average endothelial cell area was one to six times larger and the average endothelial cell perimeter was one to 2 1/2 times larger than that of a normal cornea of a subject the same age as the donor. In each corneal graft, endothelial cell areas and perimeters clustered tightly around a mean value, although the mean value for different corneas varied significantly. The thickness and transparency of each graft was normal, indicating that within the observed limits the success of the transplantation procedure did not depend on final endothelial cell size or perimeter.

Cornea↗