Cellular plasticity in the supraoptic and paraventricular nuclei after prolonged dehydration in the desert rodent Meriones shawi : Vasopressin and GFAP immunohistochemical study

• Published in: Brain research 2011-02, Vol.1375, p.85-92
• Main Authors: Gamrani, Halima, Elgot, Abdeljalil, El Hiba, Omar, Fèvre–Montange, Michelle
• Format: Article
• Language: English
• Subjects: adults; animal models; Animals; astrocytes; Astrocytes - physiology; Biological and medical sciences; Blotting, Western; Body Water - physiology; Dehydration; Dehydration - physiopathology; drinking water; Fundamental and applied biological sciences. Psychology; Gerbillinae - physiology; GFAP; Glial Fibrillary Acidic Protein - biosynthesis; Glial Fibrillary Acidic Protein - metabolism; Homeostasis - physiology; hypothalamus; Immunohistochemistry; Meriones; Meriones shawi; Midline Thalamic Nuclei - metabolism; Midline Thalamic Nuclei - physiopathology; Nerve Fibers - physiology; Neuroglia - physiology; Neurology; Neuronal Plasticity - physiology; neurons; Neurons - physiology; Osmolar Concentration; osmotic stress; Paraventricular nucleus; rodents; Supraoptic nucleus; Supraoptic Nucleus - metabolism; Supraoptic Nucleus - physiopathology; Thermoregulation. Hibernation. Estivation. Ecophysiology and environmental effects; Vasopressin; Vasopressins - biosynthesis; Vasopressins - metabolism; Vertebrates: anatomy and physiology, studies on body, several organs or systems; water deprivation
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/j.brainres.2010.10.049

Abstract Supraoptic (SON) and paraventricular (PVN) nuclei are part of the hypothalamic–neurohypophysial system, they constitute the main source for vasopressin and they represent also obvious examples of activity-dependent neuroglial plasticity. Certain physiological conditions such as dehydration are accompanied by a structural remodeling of the neurons, their synaptic inputs and their surrounding glia. In the present work, an adult Meriones shawi (a rodent adapted to desert life) is used as an animal model. Using GFAP and vasopressin expressions as indicators successively of astrocytes and neuronal activations, the effect of a prolonged episode of water deprivation on the SON and PVN, hypothalamus nuclei were examined. We studied the immunoreactivity of GFAP and vasopressin in various hydration states (total deprivation of drinking water for 1 and 2 months compared to hydrated animals). Prolonged dehydration produces an important decrease of GFAP immunoreactivity in both SON and PVN after 1 and 2 months of water restriction. This decrease is accompanied by increased vasopressin immunoreactivity following the same periods of water deprivation. These findings may explain a real communication between vasopressin neurons and their surrounding astrocytes, thus the retraction of astrocytes and their processes is accompanied by an enhancement of vasopressin neuron density and their projecting fibers in response to this osmotic stress situation. Furthermore, these data could open further investigations concerning the possible involvement of the communication between astrocytes and vasopressin neurons in both PVN and SON in the regulation of Meriones hydrous balance and resistance to dehydration.