Muscarinic acetylcholine receptors (M(1)-M(5)) regulate many key functions in the central and peripheral nervous system. Due to the lack of receptor subtype-selective ligands, however, the physiological roles of individual muscarinic receptor subtypes remain to be determined. In this study, we examined the effects of the muscarinic M(2)/M(4) receptor-preferring agonist [5R-(exo)]-6-[4-butylthio...

This study examined the distribution of muscarinic acetylcholine receptor-immunoreactive neurons in the amygdaloid complex of the rat, with emphasis on the central nucleus. The monoclonal antibody M35 raised against purified muscarinic acetylcholine receptor protein was used to visualize muscarinic acetylcholine receptor-immunoreactive cells. Muscarinic acetylcholine receptor immuno-reactivity ...

The medial septum/diagonal band (MSDB), which gives rise to the septohippocampal pathway, is a critical locus for the mnemonic effects of muscarinic drugs. Infusion of muscarinic cholinergic agonists into the MSDB enhance learning and memory processes both in young and aged rats and produce a continuous theta rhythm in the hippocampus. Intraseptal muscarinic agonists also alleviate the amnesic ...

Muscarinic receptors stimulate the secretion of acid pepsinogen and mucous in gastric mucosa. Whether muscarinic receptors are involved in the pathogenesis of benign gastric disease is unknown. Receptor changes in these conditions were therefore sought. An autoradiographic technique was developed to determine quantitatively muscarinic receptors in microtome sections of biopsy specimens obtained...

Muscarinic acetylcholine receptors are common throughout the CNS. The predominant subtypes in the brain are positively coupled to phosphoinositide hydrolysis and have been found to modulate multiple conductances. Muscarinic receptor activation is most often observed to be excitatory because of suppression of various potassium conductances. Here it is reported that three distinct effects of musc...

Some studies have shown that acetylcholine muscarinic receptors involved in the opiate reward. In the present study, the effect of intra-basolateral amygdale (BLA) acetylcholine muscarinic like receptor agonist (physostigmine) and antagonist (atropine) on the acquisition of morphine-induced place preference has been investigated in male Wistar rats. For this purpose, two 22 gauges guide cannula...

BACKGROUND Pharmaceuticals with targets in the cholinergic transmission have been used for decades and are still fundamental treatments in many diseases and conditions today. Both the transmission and the effects of the somatomotoric and the parasympathetic nervous systems may be targeted by such treatments. Irrespective of the knowledge that the effects of neuronal signalling in the nervous sy...

Acetylcholine acting on muscarinic M(3) receptors on the detrusor muscle is the principal stimulus for inducing the contractile response for urinary bladder voiding. The urinary bladder expresses, however, all cloned muscarinic receptor subtypes (M(1)-M(5)). In terms of quantity, the M(2) subtype dominates over the M(3) subtype in the detrusor, and its role in contraction seems to be primarily ...

Acetylcholine (AcCho) release from purely cholinergic Torpedo synaptosomes was evoked by K+ depolarization in the presence of Ca2+. Activation of muscarinic receptors, present in the synaptosomal fraction, by the agonist oxotremorine resulted in the inhibition of AcCho liberation. This inhibition was abolished by the muscarinic antagonist atropine, which by itself has no effect. These findings ...

Acetylcholine and muscarinic agonists inhibit chemosensory activity in the rabbit carotid sinus nerve (CSN). Because the mechanism of this inhibition is poorly understood, we have investigated the kinetics and distribution of muscarinic receptors in the rabbit carotid body with the specific muscarinic antagonist [3H]quinuclidinylbenzilate ([3H]QNB). Equilibrium binding experiments identified di...