title: An increase in glucose concentration in the lateral ventricles of the brain induces changes in autonomic nervous system activity.
abstract: OBJECTIVE
  Changes in glucose levels mobilize a neuroendocrine response that prevents or corrects glycemia. The hypothalamus is the main area of the brain that regulates glycemic homeostasis. Metabolic diseases, such as obesity and diabetes, are related to imbalance of this control.  The modulation of autonomic nervous system (ANS) activity is mediated by neuronal hypothalamic pathways. In the present work, we investigate whether glucose concentration in the hypothalamic area changes ANS activity.
  
  
  METHODS
  Glucose was administered intracerebroventricularly to  90-day-old rats, and samples of blood were collected during brain glucose infusion to measure the blood glucose and insulin levels. The electric activity of the superior vagus nerve and superior sympathetic ganglion was directly registered.
  
  
  RESULTS
  Glucose 5·6 mM infused  in the hypothalamus induced a 67·6% decrease in blood insulin concentration compared to saline infusion (P<0·01); however, no glycemia changes occurred. During glucose 5·6 mM intracerebroventricular infusion, the firing rate of the vagus nerve was decreased 39%  and sympathetic nerve activity was increased 177% compared to saline infusion (P<0·01).
  
  
  CONCLUSIONS
  Glucose injection into the brain in the hypothalamic area modulates glucose homeostasis, which might be mediated by the sensitivity of the hypothalamic area to local  changes in glucose concentration. We suggest that gluconeurons in the hypothalamus contribute to the control of glycemia through ANS activity.
authors: Laboratory of Secretion Cell Biology, Department of Cell Biology and Genetics, State University of Maringá, Brazil.
authors: R L
authors: RL
authors: Camargo
authors: R
authors: R
authors: Torrezan
authors: J C
authors: JC
authors: de Oliveira
authors: R C S
authors: RC
authors: Branco
authors: L F
authors: LF
authors: Barella
authors: S
authors: S
authors: Grassiolli
authors: C
authors: C
authors: Gravena
authors: P C F
authors: PC
authors: Mathias
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000818:Animals; D001341:Autonomic Nervous System / Q000187:drug effects / Q000502:physiology*; D001786:Blood Glucose / Q000378:metabolism*; D005215:Fasting / Q000502:physiology; D005728:Ganglia, Sympathetic / Q000187:drug effects / Q000502:physiology; D005947:Glucose / Q000008:administration & dosage*; D007275:Injections, Intravenous; D007276:Injections, Intraventricular; D007328:Insulin / Q000097:blood; D020547:Lateral Ventricles / Q000378:metabolism*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D014630:Vagus Nerve / Q000187:drug effects / Q000502:physiology
chemical_list: D001786:Blood Glucose; D007328:Insulin; D005947:Glucose