An in vitro system for perifusion of rat pancreatic islets has been utilized to define the effects of cholinergic agents on the dynamics of insulin release. In the absence of glucose the effects of either acetylcholine or acetyl-beta-methylcholine were minimal at concentrations up to 10(-5) mM. In the presence of low glucose concentration (2.4 mM), both of the muscarinic agents produced dose-de...

Objective(s):  The cholinergic system plays an important role in learning and memory. This study investigated the effects of curcumin (turmeric extract) and the cholinergic system and their interaction on memory retention of passive avoidance learning in adult male Wistar rats. Materials and Methods: At first, an injection cannula was implanted in right ventricles of the animals. One week afte...

Objective. To study the effect of immunomodulators on learning and memory and on cholinergic receptor sensitivity. Methods. Animals were initially treated for a period of 8 days with cyclosporine/levamisole/saline. They were then subjected to passive avoidance training and 48 hrs later, the retention test for the passive avoidance task was conducted. Twenty-four hours after the retention tests ...

Organophosphates (OP) are potent toxic substances used in agriculture as insecticide and pesticides, and in warfare. Over 200,000 cases of accidental toxic exposure to OPs are reported annually (Jyaratnam, 1999). OPs inhibit acetylcholine esterase (ACE), an enzyme which breaks down acetylcholine in cholinergic synapses in the peripheral nervous system (PNS) and central nervous system (CNS). Thu...

3 Introduction 4 Exposure to toxic agents present in our environment 4 Brain development 4 Cholinergic system 5 Nicotine receptors 6 Muscarinic receptors 7 The tau protein 7 Nicotine 8 Aims 9 Materials and Method 10 Treatment 10 Protein analysis 10 Statistical analysis 11 Results and Discussion 12 Concluding remarks 19 References 20