Dataset Information

Somatostatin triggers rhythmic electrical firing in hypothalamic GHRH neurons.

ABSTRACT: Hypothalamic growth hormone-releasing hormone (GHRH) neurons orchestrate body growth/maturation and have been implicated in feeding responses and ageing. However, the electrical patterns that dictate GHRH neuron functions have remained elusive. Since the inhibitory neuropeptide somatostatin (SST) is considered to be a primary oscillator of the GH axis, we examined its acute effects on GHRH neurons in brain slices from male and female GHRH-GFP mice. At the cellular level, SST irregularly suppressed GHRH neuron electrical activity, leading to slow oscillations at the population level. This resulted from an initial inhibitory action at the GHRH neuron level via K(+) channel activation, followed by a delayed, sst1/sst2 receptor-dependent unbalancing of glutamatergic and GABAergic synaptic inputs. The oscillation patterns induced by SST were sexually dimorphic, and could be explained by differential actions of SST on both GABAergic and glutamatergic currents. Thus, a tripartite neuronal circuit involving a fast hyperpolarization and a dual regulation of synaptic inputs appeared sufficient in pacing the activity of the GHRH neuronal population. These "feed-forward loops" may represent basic building blocks involved in the regulation of GHRH release and its downstream sexual specific functions.

SUBMITTER: Osterstock G

PROVIDER: S-EPMC4829871 | biostudies-literature | 2016 Apr

REPOSITORIES: biostudies-literature

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Somatostatin triggers rhythmic electrical firing in hypothalamic GHRH neurons.

Osterstock Guillaume G Mitutsova Violeta V Barre Alexander A Granier Manon M Fontanaud Pierre P Chazalon Marine M Carmignac Danielle D Robinson Iain C A F IC Low Malcolm J MJ Plesnila Nikolaus N Hodson David J DJ Mollard Patrice P Méry Pierre-François PF

Scientific reports 20160413

Hypothalamic growth hormone-releasing hormone (GHRH) neurons orchestrate body growth/maturation and have been implicated in feeding responses and ageing. However, the electrical patterns that dictate GHRH neuron functions have remained elusive. Since the inhibitory neuropeptide somatostatin (SST) is considered to be a primary oscillator of the GH axis, we examined its acute effects on GHRH neurons in brain slices from male and female GHRH-GFP mice. At the cellular level, SST irregularly suppress ...[more]

PMID: 27072430

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Somatostatin triggers rhythmic electrical firing in hypothalamic GHRH neurons.

Publications

Somatostatin triggers rhythmic electrical firing in hypothalamic GHRH neurons.

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