Innervation cholinergic

Nicotine is the main psychoactive ingredient of tobacco and is responsible for the stimulant effects and abuse/ addiction that may result form tobacco use. Cigarette smoking rapidly (in about 3 sec ) delivers pulses of nicotine into the bloodstream. Its initial effects are caused by its activation of nicotinic acetylcholine (nACh) receptors. nACh receptors are ligand-gated ion-channels and pre- and postsynaptically located. Reinforcement depends on an intact mesolimbic dopamine system (VTA). nACh receptors on VTA dopamine neurons are normally activated by cholinergic innervation from the laterodorsal tegmental nucleus or the pedunculopontine nucleus. 

Ojima H. and Yamasaki T. (1988). Cholinergic innervation of the main and the accessory olfactory bulbs of the rat as revealed by a monoclonal antibody against choline acetyltransferase. Anat Embryol 178, 481-488. 

Bouijeily N, Suszkiw JB. 1997. Developmental cholinotoxicity of lead loss of septal cholinergic neurons and long-term changes in cholinergic innervation of the hippocampus in perinatally lead-exposed rats. Brain Res 771(2) 319-328. 

The development of antibodies against ChAT allowed the distribution of neurons producing acetylcholine in the nervous system to be revealed (Mesulam et al., 1983 Armstrong et al., 1983 Jones Beaudet, 1987 Vincent Reiner, 1987). In the context of control of wakefulness and REM sleep two groups of cholinergic neurons are of primary importance. Neurons located in the basal forebrain and medial septum provide the cholinergic innervation of the cerebral... 

Frotscher M, Leranth C. 1985. Cholinergic innervation of the rat hippocampus as revealed by choline acetyltransferase immunocytochemistry a combined light and electron microscopic study. J Comp Neurol 239(2) 237-246. 

Pharmacology Trospium is an antispasmodic, antimuscarinic agent. Trospium antagonizes the effect of acetylcholine on muscarinic receptors in cholinergically innervated organs. Its parasympatholytic action reduces the tonus of smooth muscle in the bladder. Trospium increases maximum cystometric bladder capacity and volume at first detrusor contraction. 

All of the following structures have a significant cholinergic innervation EXCEPT ... 

Mechanism of Action A urinary antispasmodic agent that acts as a direct antagonist at muscarinic receptor sites in cholinergically innervated organs. Blockade of the receptors limits bladder contractions. Therapeutic Effect Reduces symptoms of bladder irritability and overactivity improves bladder capacity. 

Geula, C. (1998) Abnormalities of neural circuitry in Alzheimer s disease hippocampus and cortical cholinergic innervation, hieu-rology 51 S18—S29 discussion S65-67. 

Mesulam, M.M. (1996) The systems-level organization of cholinergic innervation in the human cerebral cortex and its alterations in Alzheimer s disease. Prog Brain Res 109 285-297. 

Coyle JT, Price DL, DeLong MR Alzheimer s disease a disorder of cortical cholinergic innervation. Science 219 1184-1190, 1983... 

The cholinesterase inhibitors can increase activity in both sympathetic and parasympathetic ganglia supplying the heart and at the acetylcholine receptors on neuroeffector cells (cardiac and vascular smooth muscles) that receive cholinergic innervation. 

Cholinesterase inhibitors have minimal effects by direct action on vascular smooth muscle because most vascular beds lack cholinergic innervation (coronary vasculature is an exception). At moderate doses, cholinesterase inhibitors cause an increase in systemic vascular resistance and blood pressure that is initiated at sympathetic ganglia in the case of quaternary nitrogen compounds and also at central sympathetic centers in the case of lipid-soluble agents. Atropine, acting in the central and peripheral nervous systems, can prevent the increase of blood pressure and the increased plasma norepinephrine. 

How and why is the limbic forebrain selectively activated in REM so as to produce this kind of affective experience The how answer is that in addition to its major cholinergic innervation from the basal forebrain the limbic area receives a direct projection from the dorsolateral pontine tegmentum, where the cholinergic neurons that become selectively active in REM sleep are found in animals. PET studies can t yet tell us if this particular brain stem region is selectively activated in human REM sleep, but we hypothesize that such a homology is likely. 

Cholinesterase inhibitors have less marked effects on vascular smooth muscle and on blood pressure than direct-acting muscarinic agonists. This is because indirect-acting drugs can modify the tone of only those vessels that are innervated by cholinergic nerves and because the net effects on vascular tone may reflect activation of both the parasympathetic and sympathetic nervous systems. The cholinomimetic effect at the smooth muscle effector tissue is minimal since few vascular beds receive cholinergic innervation. Activation of sympathetic ganglia may increase vascular resistance. 

Mesulam MM. 2004. The cholinergic innervation of the human cerebral cortex. Prog Brain Res 145 67-78. 

Sweat glands have sympathetic cholinergic innervation. Patients with cystic fibrosis secrete a large amount of salt in their sweat and this forms the basis of a diagnostic test for the condition. 

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