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M B Hancock

Publications and source records attributed to M B Hancock.

28 records · Page 2Linked to original sources
PubMed1976

Categories of axons in mammalian rami communicantes.

The present study is an electron microscope analysis of the rami communicantes and its purpose is to determine the functional categories of unmyelinate axons in these nerves. Our findings indicate that the grey rami of segments T7, T8, or T9 in the cat consist of approximately 5,000 unmyelinated axons and 20 myelinated axons, and that these axons are post-ganglionic sympathetics. Although the numbers are new data, this conclusion confirms classic work. The white rami from the same segments contain approximately 3,200 unmyelinated axons and 1,600 myelinated axons. 80-90% of the myelinated axons are preganglionic sympathetics and the remainder are presumably sensory. This conclusion is also in confirmation of classic work. The new conclusions are that approximately 30% of the unmyelinated axons are preganglionic sympathetics, approximately 60% seem to be post-ganglionic sympathetics and the surprisingly small remainder may be sensory.

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PubMedDate not supplied

Two-color immunoperoxidase staining: visualization of anatomic relationships between immunoreactive neural elements.

A method for differentially staining for two antigens in single sections is described. Paraffin-embedded or Vibratome sections are incubated in two sequences of immunoperoxidase (PAP) reagents using a diaminobenzidine (DAB)-nickel ammonium sulfate solution to localize the first antigen, and DAB alone to localize the second antigen. With these chromagens, black and amber-colored reaction products are generated at the locations of the first and second antigens, respectively. The reaction products are stable and provide excellent color contrast. With this technique, the anatomical relationships between two sets of immunoreactive elements can be studied in individual sections. Intimate spatial associations that would probably not be detected by an examination of adjacent sections stained for each antigen can be visualized with this two-color immunoperoxidase method.

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PubMedDate not supplied

Cytochemical characterization of pituitary target cells for biotinylated gonadotropin releasing hormone.

These studies describe the application of new cytochemical stains that co-localize a biotin-labeled gonadotropin releasing hormone (GnRH) analog and FSH or LH in the same field or cell. Pituitary monolayer cells were stimulated with the [D-Lys6] GnRH analog or the same analog labeled with biotin. Biotinylated [D-Lys6] GnRH exhibited a higher affinity and was 7-10 X more potent than unlabeled [D-Lys6] GnRH. The avidin-biotin peroxidase complex technique (ABC) was applied to localize the biotinylated GnRH on the cells with the use of a dense black peroxidase substrate. Specificity tests showed that the stain could be eliminated by competition with unlabeled [D-Lys6] GnRH. The GnRH stain was followed by immunocytochemical stains for LH beta, FSH beta or 25-39ACTH with a different peroxidase substrate (amber or orange-red). Stain for GnRH was found on the surfaces of 16% of the cells and 60-90% of the GnRH stained cells also stained for one of the gonadotropins. Most (90-100%) of the gonadotropes showed stain for GnRH. Our studies demonstrate that a potent biotinylated GnRH analog binds cells that can be identified specifically as gonadotropes.

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PubMedDate not supplied

Spinal projections from the nucleus locus coeruleus and nucleus subcoeruleus in the cat and monkey as demonstrated by the retrograde transport of horseradish peroxidase.

The rostral pons of the cat and rhesus monkey were examined for the presence of labeled cells following injections of horseradish peroxidase (HRP) into the lumbar spinal cord. Labeled cells were found in the ipsilateral dorsolateral pontine tegmentum and in the contralateral ventrolateral pontine reticular formation. In both the cat and monkey, labeled cells were located in the nucleus locus coeruleus, nucleus subcoeruleus, in or near the Kölliker-Fuse nucleus, and in the ventral part of the lateral parabrachial nucleus. There is a striking similarity between the distribution of HRP-labeled cells in the dorsolateral pontine tegmentum of the cat and monkey and that of catecholamine-containing cells observed in this area in previous studies.

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