Central nicotinic receptor blockade inhibits emotionally conditioned pressor responses in rats

• Published in: Cellular and molecular life sciences : CMLS Vol. 52; no. 4; pp. 348 - 352
• Main Authors: Kubo, T, Katsumata, Y, Fukumori, R, Taguchi, K, Hagiwara, Y
• Format: Journal Article
• Language: English
• Published: Switzerland 15-04-1996
• Subjects: Animals; Atropine Derivatives - pharmacology; Blood Pressure - physiology; Cholinesterase Inhibitors - pharmacology; Conditioning (Psychology); Electroshock; Fear; Heart Rate; Hexamethonium - pharmacology; Injections, Intraventricular; Male; Muscarinic Antagonists - pharmacology; Nicotinic Antagonists - pharmacology; Pentolinium Tartrate - pharmacology; Physostigmine - pharmacology; Rats; Rats, Wistar; Receptors, Nicotinic - physiology
• ISSN: 0014-4754; 1420-682X; 1420-9071
• DOI: 10.1007/BF01919539

A conditioned stimulus previously paired with electric footshock produced an increase in blood pressure in conscious, freely moving rats. The conditioned pressor response was reproducible. Intracerebroventricular injection of the nicotinic receptor antagonists hexamethonium (1-10 micrograms) or pentolinium (10 micrograms) but not the muscarinic receptor antagonist methylatropine (3 micrograms) produced an inhibition of the conditioned pressor response, whereas intraarterial injection of hexamethonium (10 micrograms) did not affect the response. Intraventricular injection of the cholinesterase inhibitor physostigmine (3-10 micrograms) produced an enhancement of the conditioned pressor response. These results are consistent with the possibility that central nicotinic receptors play a role in the expression of the emotionally conditioned pressor response in rats.