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F A Henn

Publications and source records attributed to F A Henn.

86 records · Page 5Linked to original sources
PubMed1976

Neurotransmission and glial cells: a functional relationship?

The investigations reported here demonstrate high affinity transport systems localized in glial cells which appear to be specific for amino acid neurotransmitter candidates. Data on uptake of gamma-aminobutyric acid (GABA), glutamate, glycine, and taurine, show transport systems with KT'S in the range of 10(-5) M. In addition, the distribution of the glial transport system for glycine is shown to parallel the presumed distribution of glycine as an inhibitory neurotransmitter. Results of these studies also suggest that transport studies on brain homogenates or synaptosomal preparations do not serve to localize these functions to synaptic elements as is widely believed. This report shows that glia can form vesicles during homogenization which band which synaptosomes in density gradients, and retain transport activity. Glia also may contribute to the release of neurotransmitters via control of the extracellular Ca++ concentration. This is shown by the ability of GABA in the extracellular media to cause release of Ca++ by glia.

Amino Acids↗
PubMed1976

Forensic psychiatry: profiles of two types of sex offenders.

The authors examined records of 239 individuals charged with sexual offenses and referred by the courts to a forensic service. Defendants charged with rape were typically under 30 with histories of antisocial behavior that included other types of violence. Major mental illness was rare in this group. Child molesters in the sample were of no particular age, usually had no history of violent behavior, and had a low incidence of psychosis. The most common secondary diagnosis in both groups was alcohol or drug abuse.

Alcoholism↗
PubMed1976

Forensic psychiatry: diagnosis and criminal responsibility.

An examination of the primary and secondary diagnoses of 1195 defendants admitted to an urban forensic service was carried out. This indicated that personality disorders dominated the referral patterns from the court. Of those conditions which could produce thought disorders, schizophrenia dominated. An analysis of the prevalence of schizophrenia among defendants charged with homicide in St. Louis revealed a rate of schizophrenia similar to that found in the general population. Organic brain syndromes resulted in a large proportion of assaultive behavior, and these cases also involved a large number of secondary diagnoses. Alcohol and drug abuse were the most common secondary diagnoses. In general, no correlation between psychiatric diagnosis and types of criminal activity was found.

Alcoholism↗
PubMed1972

Preparation of plasma membrane from isolated neurons.

A bulk fraction enriched with respect to neuronal cell bodies was used as starting material for the isolation of neuronal plasma membrane The cells were gently homogenized in isotonic sucrose and a crude membrane containing fraction sedimented at 3000 g. Subsequently, the membrane fraction was purified on a discontinuous sucrose density gradient between 35% and 25 5% sucrose (w/w). Enzymatic analyses showed a 4-5-fold enrichment in plasma membrane markers, and a 10-15% contamination of mitochondrial and microsomal material. Electron micrographs of the membrane fraction confirmed the enzymatic data Fragmented membranes were found, mainly in vesicular form No ribosomes, but a few mitochondria and some multilamellar membranes were seen

Adenosine Triphosphatases↗
PubMed1971

Glial cell function: uptake of transmitter substances.

Rabbit-brain fractions enriched in neuronal cell bodies and in glial cells accumulated norepinephrine, serotonin, dopamine, and gamma-aminobutyric acid, substances believed to serve as neurotransmitters in the central nervous system. Both neurons and glia were able to concentrate the monoamine transmitters about 4-fold from a medium containing 0.1-1 muM concentrations. However, the glial-cell fraction concentrated aminobutyrate over a 100-fold from the medium, in contrast to the neuronal fraction, which concentrated this amino acid only 4-fold. The uptake of aminobutyrate by glial cells was 30-50% of that of synaptosome preparations. Its uptake in all fractions was temperature sensitive, sensitive to metabolic inhibitors, and exhibited K(m) values of 0.72 muM for the neuronal fraction, 0.42 muM for the synaptosomal fraction, and 0.27 muM for the glial-cell fraction. These results are interpreted as evidence that the glial cell is involved in limiting the extracellular build-up of substances that might trigger synaptic transmission by removing any transmitters that may diffuse out of the synaptic cleft during the transmission of impulses. The possible function of the enormous ability of glia and synaptosomes to accumulate aminobutyrate is discussed in light of the actions and distribution of this substance in the central nervous system.

Aminobutyrates↗
PubMedDate not supplied

Demonstration of adenosine receptors on mouse cerebral smooth muscle membranes.

Adenosine receptors have been identified on brain cortical membranes and microvascular preparations. However, they have not been demonstrated on specific microvascular elements in isolation. 2-3H-chloroadenosine was used as a ligand to investigate the presence of adenosine receptors on isolated mouse cerebral smooth muscle membranes. The binding studies reveal the presence of a high affinity binding site with a Kd value of 33.3 nM and a maximal binding capacity (Bmax) of 283 fmol/mg protein. These findings demonstrate that there is an adenosine receptor on cerebral smooth muscle membranes.

2-Chloroadenosine↗