Arcuate nucleus neurons that project to the hypothalamic paraventricular nucleus: neuropeptidergic identity and consequences of adrenalectomy on mRNA levels in the rat. 1995

R A Baker, and M Herkenham
Section of Functional Neuroanatomy, National Institute of Mental Health, Bethesda, Maryland 20892, USA.

The possible role that the hypothalamic arcuate nucleus might play in mediating the increase in paraventricular nucleus corticotropin-releasing hormone mRNA levels following adrenalectomy was investigated in two series of experiments. In the first series in situ hybridization histochemistry was used to quantify levels of eight accurate nucleus neuropeptide and neurotransmitter mRNAs in neurons that potentially relay adrenal steroid feedback to the paraventricular nucleus. In the second series of experiments, arcuate neuropeptidergic projections to the hypothalamic paraventricular nucleus were characterized using retrograde tracing in combination with in situ hybridization histochemistry. Despite an increase in paraventricular nucleus corticotropin-releasing hormone (60%) and pituitary proopiomelanocortin mRNA levels (sixfold), arcuate mRNA levels for proopiomelanocortin, neuropeptide Y, somatostatin, galanin, dynorphin, tyrosine hydroxylase, glutamate decarboxylase, and the glucocorticoid receptor were unchanged 14 days following adrenalectomy. Neuropeptidergic characterization of arcuatoparaventricular projections was achieved by injection of the retrograde tracer fluorogold into the paraventricular nucleus; retrogradely labeled neurons were characterized with polyclonal antisera against fluorogold in combination with oligonucleotide probes directed against neuropeptide Y, proopiomelanocortin, or somatostatin. Out of these three arcuate neuropeptide Y mRNA was contained in 18% of the fluorogold-positive neurons in the arcuate, proopiomelanocortin mRNA was contained in 8%, and somatostatin mRNA was contained in 6%. Overall, the results from both experiments suggest that the arcuatoparaventricular neuropeptide Y, proopiomelanocortin, and somatostatin projections are not sensitive to a chronic (14 day) lack of adrenal steroids. These projections as well as the other arcuate neurotransmitter and neuropeptide systems appear not to contribute to the persistent elevations in paraventricular nucleus corticotropin-releasing hormone mRNA levels or pituitary proopiomelanocortin mRNA levels found in 14 day adrenalectomized rats.

UI MeSH Term Description Entries
D007150 Immunohistochemistry Histochemical localization of immunoreactive substances using labeled antibodies as reagents. Immunocytochemistry,Immunogold Techniques,Immunogold-Silver Techniques,Immunohistocytochemistry,Immunolabeling Techniques,Immunogold Technics,Immunogold-Silver Technics,Immunolabeling Technics,Immunogold Silver Technics,Immunogold Silver Techniques,Immunogold Technic,Immunogold Technique,Immunogold-Silver Technic,Immunogold-Silver Technique,Immunolabeling Technic,Immunolabeling Technique,Technic, Immunogold,Technic, Immunogold-Silver,Technic, Immunolabeling,Technics, Immunogold,Technics, Immunogold-Silver,Technics, Immunolabeling,Technique, Immunogold,Technique, Immunogold-Silver,Technique, Immunolabeling,Techniques, Immunogold,Techniques, Immunogold-Silver,Techniques, Immunolabeling
D008297 Male Males
D009474 Neurons The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM. Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D009479 Neuropeptides Peptides released by NEURONS as intercellular messengers. Many neuropeptides are also hormones released by non-neuronal cells. Neuropeptide
D010286 Paraventricular Hypothalamic Nucleus Nucleus in the anterior part of the HYPOTHALAMUS. Hypothalamic Paraventricular Nucleus,Paraventricular Nucleus,Hypothalamic Nucleus, Paraventricular,Nucleus, Hypothalamic Paraventricular,Nucleus, Paraventricular,Nucleus, Paraventricular Hypothalamic,Paraventricular Nucleus, Hypothalamic
D003345 Corticosterone An adrenocortical steroid that has modest but significant activities as a mineralocorticoid and a glucocorticoid. (From Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed, p1437)
D005246 Feedback A mechanism of communication within a system in that the input signal generates an output response which returns to influence the continued activity or productivity of that system. Feedbacks
D005456 Fluorescent Dyes Chemicals that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags. Flourescent Agent,Fluorescent Dye,Fluorescent Probe,Fluorescent Probes,Fluorochrome,Fluorochromes,Fluorogenic Substrates,Fluorescence Agents,Fluorescent Agents,Fluorogenic Substrate,Agents, Fluorescence,Agents, Fluorescent,Dyes, Fluorescent,Probes, Fluorescent,Substrates, Fluorogenic
D006651 Histocytochemistry Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods. Cytochemistry
D000311 Adrenal Glands A pair of glands located at the cranial pole of each of the two KIDNEYS. Each adrenal gland is composed of two distinct endocrine tissues with separate embryonic origins, the ADRENAL CORTEX producing STEROIDS and the ADRENAL MEDULLA producing NEUROTRANSMITTERS. Adrenal Gland,Gland, Adrenal,Glands, Adrenal

Related Publications

R A Baker, and M Herkenham
August 1997, The Journal of comparative neurology,
R A Baker, and M Herkenham
April 2001, The Journal of comparative neurology,
R A Baker, and M Herkenham
November 1990, Brain research bulletin,
R A Baker, and M Herkenham
January 1991, Brain research. Molecular brain research,
R A Baker, and M Herkenham
May 1998, The American journal of physiology,
R A Baker, and M Herkenham
October 2001, American journal of physiology. Regulatory, integrative and comparative physiology,
Copied contents to your clipboard!