Thirst Is Associated with Suppression of Habenula Output and Active Stress Coping: Is there a Role for a Non-canonical Vasopressin-Glutamate Pathway?

Front Neural Circuits. 2016 Mar 31:10:13. doi: 10.3389/fncir.2016.00013. eCollection 2016.


Water-homeostasis is a fundamental physiological process for terrestrial life. In vertebrates, thirst drives water intake, but the neuronal circuits that connect the physiology of water regulation with emotional context are poorly understood. Vasopressin (VP) is a prominent messenger in this circuit, as well as L-glutamate. We have investigated the role of a VP circuit and interaction between thirst and motivational behaviors evoked by life-threatening stimuli in rats. We demonstrate a direct pathway from hypothalamic paraventricular VP-expressing, glutamatergic magnocellular neurons to the medial division of lateral habenula (LHbM), a region containing GABAergic neurons. In vivo recording and juxtacellular labeling revealed that GABAergic neurons in the LHbM had locally branching axons, and received VP-positive axon terminal contacts on their dendrites. Water deprivation significantly reduced freezing and immobility behaviors evoked by innate fear and behavioral despair, respectively, accompanied by decreased Fos expression in the lateral habenula. Our results reveal a novel VP-expressing hypothalamus to the LHbM circuit that is likely to evoke GABA-mediated inhibition in the LHbM, which promotes escape behavior during stress coping.

Keywords: dense core vesicle; fluorogold; homeostasis; interneuron; juxtacellular labeling; metastress coping; motivation; synapsis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cats
  • Colchicine / pharmacology
  • Disease Models, Animal
  • Fear / psychology
  • Glutamate Decarboxylase / metabolism
  • Glutamic Acid / metabolism*
  • Habenula / cytology
  • Habenula / drug effects
  • Habenula / physiology*
  • Habenula / ultrastructure
  • Male
  • Neurons / drug effects
  • Neurons / ultrastructure
  • Oncogene Proteins v-fos / metabolism
  • Paraventricular Hypothalamic Nucleus / cytology
  • Paraventricular Hypothalamic Nucleus / ultrastructure
  • Rats
  • Rats, Wistar
  • Signal Transduction / drug effects
  • Signal Transduction / physiology*
  • Stress, Psychological / pathology
  • Stress, Psychological / physiopathology*
  • Synapses / metabolism
  • Thirst / drug effects
  • Thirst / physiology*
  • Tubulin Modulators / pharmacology
  • Vasopressins / metabolism*
  • Water Deprivation / physiology
  • gamma-Aminobutyric Acid / metabolism


  • Oncogene Proteins v-fos
  • Tubulin Modulators
  • Vasopressins
  • Glutamic Acid
  • gamma-Aminobutyric Acid
  • Glutamate Decarboxylase
  • Colchicine