Differential profiles of nitric oxide and norepinephrine releases in the paraventricular nucleus region in response to mild footshock in rats

• Published in: Brain research Vol. 862; no. 1; pp. 17 - 25
• Main Authors: Ishizuka, Yuta, Ishida, Yasushi, Jin, Qing-Hua, Kato, Kazuo, Kunitake, Takato, Mitsuyama, Yoshio, Kannan, Hiroshi
• Format: Journal Article
• Language: English
• Published: London Elsevier B.V 17-04-2000; Amsterdam Elsevier; New York, NY
• Subjects: Animals; Biological and medical sciences; Brain Chemistry - drug effects; Central nervous system; Central neurotransmission. Neuromudulation. Pathways and receptors; Electroshock; Enzyme Inhibitors - pharmacology; Excitatory Amino Acid Agonists - pharmacology; Footshock; Fundamental and applied biological sciences. Psychology; Interleukin-1 - metabolism; Interleukin-1β; Male; Medial prefrontal cortex; Microdialysis; N-Methylaspartate - pharmacology; NG-Nitroarginine Methyl Ester - pharmacology; Nitric oxide; Nitric Oxide - metabolism; Norepinephrine; Norepinephrine - metabolism; Paraventricular Hypothalamic Nucleus - metabolism; Paraventricular nucleus region; Prefrontal Cortex - metabolism; Rats; Rats, Wistar; Reaction Time - physiology; Stress, Physiological - metabolism; Vertebrates: nervous system and sense organs; Footshock; Medial prefrontal cortex; Interleukin-1β; Nitric oxide; Paraventricular nucleus region; Norepinephrine; Neural basis of behavior; Rat; Cytokine; Rodentia; Central nervous system; Interleukin 1β; Prefrontal cortex; Paraventricular nucleus; Catecholamine; Stress; Vertebrata; Mammalia; Release; Brain (vertebrata)
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/S0006-8993(00)02061-8

The purpose of this study was to determine whether the application of mild intermittent footshock stress can cause changes in the nitric oxide (NO) and norepinephrine (NE) releases in the hypothalamic paraventricular nucleus (PVN) region and medial prefrontal cortex (mPFC). Extracellular levels of NO metabolites and NE in the PVN region and mPFC were determined using an in vivo brain microdialysis technique in conscious rats. In the PVN region, we demonstrated that perfusion of
N-methyl-
d-aspartate through a microdialysis probe resulted in a dose-dependent increase in NO metabolite levels, whereas intraperitoneal administration of
N
G-nitro-
l-arginine methyl ester produced a dose-dependent reduction in the levels of NO metabolites. The levels of NO metabolites in the PVN region increased after intraperitoneal administration of interleukin-1β in a dose-dependent manner, as we previously reported. This increase in NO metabolite levels was abolished 60 min after systemic administration of
N
G-nitro-
l-arginine methyl ester compared to the vehicle-treated control group. Twenty minutes of intermittent footshock induced NE release but did not induce NO release in the PVN region. On the contrary, in the mPFC, 20 min of intermittent footshock induced both NO and NE releases. The present results reveal different patterns and time courses in NO and NE releases between the PVN region and the mPFC in response to mild intermittent footshock stress. These findings are likely to have helpful suggestions for our understanding of the hypothalamic–pituitary–adrenal axis and the limbic forebrain system response to different kinds of stress.