A morphometric analysis of functionally defined subpopulations of neurons in the paraventricular nucleus of the rat with observations on the effects of colchicine

Two populations of neurons in the paraventricular nucleus of the hypothalamus that have different efferent projections and physiological roles in the regulation of visceral responses were characterized morphologically with a combined intracellular filling, retrograde tracer, and immunohistochemical method. Neuroendocrine cells were retrogradely labeled by an intravenous injection of Fast blue, and distinguished from descending neurons that were retrogradely labeled by an injection of fluorogold into the spinal cord. Retrogradely labeled neurons were selectively penetrated and filled intracellularly with Lucifer yellow to visualize detailed features of their morphology. Corticotropin-releasing hormone (CRH)-containing neurons were distinguished from other neuroendocrine cells by immunostaining the tissue with an antiserum to rat CRH. Morphometric features of defined populations of neurons were then quantified and reconstructed graphically to generate multicellular montage drawings that demonstrate their spatial organization. Descending neurons were further separated into dorsal and ventral medial parvicellular components, while the neuroendocrine population was differentiated into parvicellular and magnocellular groups. The mean somal areas, total dendritic lengths, and spine densities were compared between groups of neurons, and these showed significant differences across cell types. These measures were also dramatically affected by colchicine, which appears to induce the formation of new dendritic appendages, swelling of the soma, and reduction of dendritic length. Whether colchicine is acting directly upon cytoskeletal structures or indirectly by altering the physiology of the cell is unclear. However, the precise effects of colchicine on mean somal area, total dendritic length, and spine density appear to be dependent upon individual cell type. Colchicine may therefore act in a nonspecific, but nonetheless highly selective, manner in disrupting an endogenous mechanism regulating the number, morphology, and location of spines.

• Publication year

  1989

• Venue

  Journal of Neuroscience

• Publication date

  1989-04-01

• Fields of study

  Biology, Medicine

• Identifiers
  DOI 10.1523/JNEUROSCI.09-04-01375.1989PMID 2784832PMCID PMC6569852
• External record

  Open on Semantic Scholar

• Source metadata

  Semantic Scholar, PubMed

• Immunostaining with antiserum to corticotropin-releasing hormone separated CRH-containing neurons from other neuroendocrine cells.

  Confidence 0.88

  박진우 (dztg5apj7m) extraction뀨 (7c402c1b98) reviewmexicorea (qjvnbu8xg3) reviewKiller Whale (322360f1c1) review
• Colchicine altered neuronal morphology by promoting new dendritic appendages, swelling somata, and reducing dendritic length, with effects that varied by neuronal cell type.

  Confidence 0.92

  박진우 (dztg5apj7m) extraction뀨 (7c402c1b98) reviewmexicorea (qjvnbu8xg3) reviewKiller Whale (322360f1c1) review
• Morphometric comparisons in the paraventricular nucleus of the hypothalamus showed significant differences in somal area, dendritic length, and spine density across the defined neuronal populations.

  Confidence 0.93

  박진우 (dztg5apj7m) extraction뀨 (7c402c1b98) reviewmexicorea (qjvnbu8xg3) reviewKiller Whale (322360f1c1) review
• Fast blue and fluorogold retrograde labeling distinguished neuroendocrine cells from descending neurons, and Lucifer yellow intracellular filling was used to visualize their detailed morphology.

  Confidence 0.95

  박진우 (dztg5apj7m) extraction뀨 (7c402c1b98) reviewmexicorea (qjvnbu8xg3) reviewKiller Whale (322360f1c1) review

• colchicine

  chemical reagent, drug

  A microtubule-disrupting compound applied in the tissue to assess its effects on neuronal morphology.

  박진우 (dztg5apj7m) extraction뀨 (7c402c1b98) reviewmexicorea (qjvnbu8xg3) reviewKiller Whale (322360f1c1) review
• corticotropin-releasing hormone

  peptide hormone, molecular marker

  A hypothalamic peptide used here as an immunohistochemical marker to identify a subset of neuroendocrine neurons.

  Aliases: CRH

  박진우 (dztg5apj7m) extraction뀨 (7c402c1b98) reviewmexicorea (qjvnbu8xg3) reviewKiller Whale (322360f1c1) review
• dendritic spines

  cellular feature

  Small dendritic protrusions whose density and morphology were quantified in the analyzed neurons.

  Aliases: spines

  박진우 (dztg5apj7m) extraction뀨 (7c402c1b98) reviewmexicorea (qjvnbu8xg3) reviewKiller Whale (322360f1c1) review
• descending neurons

  cell type

  Paraventricular neurons that project to the spinal cord and were identified by spinal fluorogold labeling.

  Aliases: spinally projecting neurons

  박진우 (dztg5apj7m) extraction뀨 (7c402c1b98) reviewmexicorea (qjvnbu8xg3) reviewKiller Whale (322360f1c1) review
• fast blue

  tracer, dye

  An intravenous retrograde tracer used to label neuroendocrine cells in the hypothalamus.

  Aliases: FB

  박진우 (dztg5apj7m) extraction뀨 (7c402c1b98) reviewmexicorea (qjvnbu8xg3) reviewKiller Whale (322360f1c1) review
• fluorogold

  tracer, dye

  A retrograde tracer injected into the spinal cord to label descending neurons.

  Aliases: Fluoro-Gold, FG

  박진우 (dztg5apj7m) extraction뀨 (7c402c1b98) reviewmexicorea (qjvnbu8xg3) reviewKiller Whale (322360f1c1) review
• lucifer yellow

  dye, labeling reagent

  A fluorescent intracellular dye used to fill individually penetrated neurons and reveal detailed cell morphology.

  Aliases: LY

  박진우 (dztg5apj7m) extraction뀨 (7c402c1b98) reviewmexicorea (qjvnbu8xg3) reviewKiller Whale (322360f1c1) review
• neuroendocrine cells

  cell type

  Neurons in the paraventricular nucleus that project to the circulation and were identified by intravenous Fast blue labeling.

  Aliases: neuroendocrine neurons

  박진우 (dztg5apj7m) extraction뀨 (7c402c1b98) reviewmexicorea (qjvnbu8xg3) reviewKiller Whale (322360f1c1) review
• paraventricular nucleus of the hypothalamus

  anatomical structure

  A hypothalamic nucleus that contains the neuronal populations analyzed for morphology and projection pattern.

  Aliases: PVN

  박진우 (dztg5apj7m) extraction뀨 (7c402c1b98) reviewmexicorea (qjvnbu8xg3) reviewKiller Whale (322360f1c1) review

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