Activation of neurons in the hypothalamic dorsomedial nucleus via hypothalamic projections of the nucleus of the solitary tract following refeeding of fasted rats

Eva Renner, Kinga I. Szabó-Meltzer, Nela Puskás, Zsuzsanna E. Tóth, Arpád Dobolyi, Miklós Palkovits

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

We report that satiation evokes neuronal activity in the ventral subdivision of the hypothalamic dorsomedial nucleus (DMH) as indicated by increased c-fos expression in response to refeeding in fasted rats. The absence of significant Fos activation following food presentation without consumption suggests that satiation but not craving for food elicits the activation of ventral DMH neurons. The distribution pattern of the prolactin-releasing peptide (PrRP)-immunoreactive (ir) network showed remarkable correlations with the distribution of activated neurons within the DMH. The PrRP-ir fibers and terminals were immunolabeled with tyrosine hydroxylase, suggesting their origin in lower brainstem instead of local, hypothalamic PrRP cells. PrRP-ir fibers arising from neurons of the nucleus of the solitary tract could be followed to the hypothalamus. Unilateral transections of these fibers at pontine and caudal hypothalamic levels resulted in a disappearance of the dense PrRP-ir network in the ventral DMH while PrRP immunoreactivity was increased in transected fibers caudal to the knife cuts as well as in perikarya of the nucleus of the solitary tract ipsilateral to the transections. In accord with these changes, the number of Fos-expressing neurons following refeeding declined in the ipsilateral but remained high in the contralateral DMH. However, the Fos response in the ventral DMH was not attenuated following chemical lesion (neonatal monosodium glutamate treatment) of the hypothalamic arcuate nucleus, another possible source of DMH inputs. These findings suggest that PrRP projections from the nucleus of the solitary tract contribute to the activation of ventral DMH neurons during refeeding, possibly by transferring information on cholecystokinin-mediated satiation.

Original languageEnglish
Pages (from-to)302-314
Number of pages13
JournalEuropean Journal of Neuroscience
Volume31
Issue number2
DOIs
Publication statusPublished - Jan 1 2010

Keywords

  • C-fos activation
  • Food intake
  • Prolactin-releasing peptide
  • Satiety
  • Surgical transections

ASJC Scopus subject areas

  • Neuroscience(all)

Fingerprint Dive into the research topics of 'Activation of neurons in the hypothalamic dorsomedial nucleus via hypothalamic projections of the nucleus of the solitary tract following refeeding of fasted rats'. Together they form a unique fingerprint.

  • Cite this