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J Storm-Mathisen

Publications and source records attributed to J Storm-Mathisen.

At least 145 records · Page 8Linked to original sources
PubMed1977

Localization of putative transmitters in the hippocampal formation: with a note on the connections to septum and hypothalamus.

Biochemical assays on microdissected samples, denervation studies, subcellular fractionation, and light and electron microscopic autoradiography of high affinity uptake have been performed to study the cellular localization of transmitter candidates in the rat hippocampal formation. High affinity uptake of glutamate and aspartate is localized in the terminals of several excitatory systems, such as the entorhino-dentate fibres (perforant path), mossy fibres (from granular cells) and pyramidal cell axons. Thus, in stratum radiatum and oriens of CA1, 85% of glutamate and asparate uptake and 40% of glutamate and aspartate content are lost after lesions of ipsilateral plus commissural fibres from CA3/CA4. Hippocampal efferents also take up aspartate and glutamate, since these activities are heavily reduced in the lateral septum and mamillary bodies after transection of fimbria and the dorsal fornix. The synthesis (by glutamic acid decarboxylase), content and high affinity uptake of gamma-aminobutyrate (GABA) are not reduced after lesions of these or other projection fibre systems. A localization in intrinsic neurons is confirmed by a selective loss of glutamic acid decarboxylase after local injections of kainic acid. Peak concentrations of the enzyme occur near the pyramidal and granular cell bodies, corresponding to the site of the inhibitory basket cell terminals, and in the outer parts of the molecular layers. Some 85% of glutamic acid decarboxylase is situated in 'nerve ending particles'. Acetylcholine synthesis (by choline acetyltransferase) disappears after lesions of septo-hippocampal fibres. Since 80% of the hippocampal choline acetyltransferase is in 'nerve ending particles', the characteristic topographical distribution of this enzyme should reflect the distribution of cholinergic septo-hippocampal afferents. Serotonin, noradrenaline, dopamine and histamine are located/synthesized in afferent fibre systems. Some monoamine-containing afferents to the hippocampal formation pass via the septal area, others via the amygdala. The hippocampal formation also contains nerve elements reacting with antibodies against neuroactive peptides, such as enkephalin, substance P, somatostatin and gastrin/cholecystokinin.

Acetylcholine↗
PubMed1975

High affinity uptake of GABA in presumed GABA-ERGIC nerve endings in rat brain.

After interuption of the striato-nigral pathway uptake of gamma-aminobutyric acid (GABA) in the substatia nigra decresaed with 7 days to a constant level 30-40% of the normal. Concomitantly glutamate decarbosylase (GAD) was reduced to 10%. Hence about two-thirds of the GABA uptake activity in substantia nigra are localised, to the alleged GABA-ergic nerve elements originating from corpus striatum. The lesion resistant part of the uptake is probably not localised in cell bodies or large processes, since it was the same in tissuse prisms as in whole homogenates and crude nerve ending fractions. It was also not influenced by aminoozyacetic acid, which would argue against a localisation in glia. Whereas GAD was recovered mainly in a "heavy" nerve ending fraction, a large proportion of the GABA uptake was situated in a "light" fraction. After hemisections, GABA uptake was reduced to a similar extent in both fractions. It is suggested that whereas GAD is concentrated in nerve terminals, a significant proportion of the GABA uptake may be localised in preterminal axon branches in the substantia nigra. GABA uptake in the dorsal part of the lateral vestibular nucleus was not reduced by interruption of the Purkinje axons from the cerebellar vermis whereas GAD was reduced 50%. This indicates that the reuptake mechanism is not concentrated in the Prukinje axon terminals. In the hippocampus neither GABA nor GAD were reduced by lesions of afferent nerve pathoways, in accordance with previous results showing that in this region GABA producing neurones are intrinsic. The order of ratiols of GABA uptake to particulate GAD activity in different regions was: hippocampus greater than cerebellar cortex greater than substantia nigra greater than dorsal part of lateral vestibular necleus approximately equal to nucleus interpositus. The ratio may relfect the degree of specific localisation of the GABA uptake mechanism to the GABA-ergic structures.

Aminobutyrates↗