Pharmacological evidence of muscarinic-cholinergic sensitization following chronic stress.
BACKGROUND
Although much evidence supports a major role of brain cholinergic transmission in memory consolidation processes, little is known about cholinergic functioning under environmental pressure.


OBJECTIVE
The present experiments were aimed at investigating possible functional adaptation of muscarinic receptors promoted by a chronic stressful procedure in an inbred strain of mice highly susceptible to stress.


METHODS
We tested the effects of post-trial administration of a cholinergic agonist and a muscarinic antagonist on the retention of a passive avoidance task in control animals and compared these effects with those observed following food restriction.


RESULTS
Food restriction enhanced the facilitatory effects of oxotremorine and reduced the impairing effects of atropine on memory consolidation.


CONCLUSIONS
Our results support the view that chronic sensitization of muscarinic receptors occurs following chronic stress.
Orsini
C
C
IRCCS, Fondazione Santa Lucia, Rome, Italy.
Castellano
C
C
Cabib
S
S
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001362:Avoidance Learning / Q000187:drug effects; D005508:Food Deprivation / Q000502:physiology; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D018721:Muscarinic Agonists / Q000494:pharmacology; D018727:Muscarinic Antagonists / Q000494:pharmacology; D010095:Oxotremorine / Q000494:pharmacology; D011950:Receptors, Cholinergic / Q000187:drug effects*; D011976:Receptors, Muscarinic / Q000187:drug effects*; D013315:Stress, Psychological / Q000523:psychology*
D018721:Muscarinic Agonists; D018727:Muscarinic Antagonists; D011950:Receptors, Cholinergic; D011976:Receptors, Muscarinic; D010095:Oxotremorine; D001285:Atropine