Effects of pertussis toxin on the behavioural and ECoG spectrum changes induced by clonidine and yohimbine after their microinfusion into the locus coeruleus

• Published in: British journal of pharmacology Vol. 96; no. 1; pp. 59 - 64
• Main Authors: Sarro, G.B., Bagetta, G., Ascioti, C., Libri, V., Nisticò, G.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.01.1989; Nature Publishing
• Subjects: Animals; Antihypertensive agents; Behavior, Animal - drug effects; Biological and medical sciences; Bordetella pertussis; Cardiovascular system; Clonidine - antagonists & inhibitors; Electroencephalography; Infusions, Parenteral; Locus Coeruleus; Male; Medical sciences; Pertussis Toxin; Pharmacology. Drug treatments; Rats; Rats, Inbred Strains; Virulence Factors, Bordetella - toxicity; Yohimbine - antagonists & inhibitors; α2-Adrenergic receptor; GTP; Vasodilator agent; Rat; Interaction; Rodentia; Central nervous system; Electrophysiology; Bordetella pertussis; Toxin; Vertebrata; Regulation(control); Mammalia; Animal; Intracerebral administration; Bacteria; Antihypertensive agent; Behavior; Mechanism of action; Locus coeruleus; Electrocorticography
• ISSN: 0007-1188; 1476-5381
• DOI: 10.1111/j.1476-5381.1989.tb11784.x

1 Pertussis toxin, a substance which interferes selectively with receptor‐mediated signal transduction mechanisms, was injected into the locus coeruleus of rats 1, 2, 3, 6 or 10 days before the microinjection of clonidine or yohimbine into the same site. 2 Clonidine produced in control rats typical behavioural sedation and/or sleep and ECoG synchronization while yohimbine produced behavioural arousal and ECoG desynchronization. 3 The behavioural and ECoG effects of both compounds were blocked in animals pretreated with pertussis toxin. This activity was more marked from 2 to 6 days after pertussis toxin pretreatment and was restored 10 days after toxin administration. In addition, the behavioural and ECoG slow‐wave sleep observed after intraperitoneal administration of clonidine (0.2 μmol kg−1) was significantly reduced by prior (3 days) microinfusion of pertussis toxin into the locus coeruleus. 4 These results are consistent with the hypothesis that the behavioural and ECoG effects of clonidine and yohimbine are mediated via a guanine regulatory protein which is affected by pertussis toxin.