QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

This Article Full Text (PDF) Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Stafford, I. L. Articles by Jacobs, B. L. Search for Related Content PubMed PubMed Citation Articles by Stafford, I. L. Articles by Jacobs, B. L.

 Previous Article  |  Next Article 

Journal of Neuroscience, Vol 10, 99-107, Copyright © 1990 by Society for Neuroscience

ARTICLE

Noradrenergic modulation of the masseteric reflex in behaving cats. II. Physiological studies

IL Stafford and BL Jacobs
Department of Psychology, Princeton University, New Jersey 08544.

Studies in the preceding paper demonstrated that the amplitude of the masseteric reflex in behaving cats is augmented by pharmacological manipulations that increase norepinephrine (NE) tone in the motor trigeminal nucleus (MoV) through exogenous means. The present studies examine whether such a relationship also exists under physiological conditions, i.e., whether physiological increases in NE synaptic activity are correlated with increases in the reflex amplitude. The masseteric reflex was elicited in behaving cats by electrical stimulation of the mesencephalic trigeminal nucleus (MesV) and the response recorded via electrodes permanently placed in the masseter muscle. Following baseline measures of the reflex amplitude, the reflex was gain elicited while cats were exposed to various environmental stimuli known to activate NE neurons: 15 min of 100-dB white noise, confrontation with a dog, or auditory clicks presented repetitively at various intervals prior to MesV stimulation. Presentation of the white noise or the dog significantly facilitated the reflex response for the duration of the exposure. The clicks produced reflex facilitation at 100 and 150 msec following their presentation and reflex suppression at 20 msec. Two approaches were then employed to determine whether NE mediated, at least in part, augmentation of the reflex produced by these environmental conditions. In the first, cats were given either the alpha-1-noradrenergic antagonist prazosin (5 mg/kg, i.p.) or the serotonin antagonist methysergide (0.5 mg/kg, i.p.). In all cases, prazosin blocked the reflex augmentation whereas methysergide was without effect.(ABSTRACT TRUNCATED AT 250 WORDS)

This article has been cited by other articles:

				S. A. Hackley and F. Valle-Inclán Accessory Stimulus Effects on Response Selection: Does Arousal Speed Decision Making? J. Cogn. Neurosci., May 1, 1999; 11(3): 321 - 329. [Abstract] [Full Text]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help