ACh Content Research Articles

Ecology and Behavior of the Pouched Mouse, Saccostomus mearnsi, in Central Kenya

I investigated the ecology and behavior of Saccostomus mearnsi, a medium-sized semi­ fossorial murid rodent for 15 months in a tropical savanna of central Kenya. This poorly known species is the dominant small mammal in this widespread habitat, although it has never before been reported in high local abundance. On three replicated I-ha grids, S. mearnsi exhibited a 2.5-fold change in abundance over 15 months from 16 ± 3.5 (SE) to 42 ± 7.5 individualslha. S. mearnsi had strongly seasonal reproduction, with almost all females in breeding condition following the rainy season, while only 10% were in breeding condition during the dry season. Eighty-five percent of males, however, remained in breed­ ing condition throughout the year. Adults of both sexes exhibited great variation in body weight (males, 48-121 g; females, 39-94 g). There was significant seasonal variation in body weight for both sexes. Home ranges of males (0.21 ± 0.02 ha) were three times the size of those of females (0.06 ± 0.01 ha); and the average of the maximum distances moved by males between captures varied significantly between seasons. Analyses of stom­ ach contents showed that S. mearnsi was omnivorous, consuming primarily forbs during the dry season and seeds following the rains. Adults share burrow entrances in termite mounds; whether or not they nest individually or communally remains to be determined.

Interaction of carbofuran with the acetylcholinesterase from the brain of the teleost, clarias batrachus

Acetylcholinesterase (EC 3.1.1.7, AChE) of Ciarías batrachus, a fresh water teleost, was localised both in the particulate and soluble fractions of the cell‐free homogenate of the fish brain. The particulate bound enzyme could be solubilised using phosphate buffer containing Triton X‐100 resulting in maximum recovery of enzyme (?98%) in the supernatant. The C. batrachus when exposed to subacute concentrations (0.01 and 0.02 mgL–1) of carbofuran (LC50 ? 0.2 mgL–1) for varying incubation periods, the pesticide caused drastic changes in activity of AChE and protein content in fish brain tissues. Carbofuran exerted inhibitory effect on AChE activity from the brain of C. batrachus. It also caused decrease in the level of fish brain protein. The decrease in AChE activity was maximum when the fish was exposed for 30 days with higher carbofuran concentration (0.02 mgL–1), whereas the decrease in brain protein content was maximum when the fish was exposed for 15 days with same concentration of carbofuran. However, after 30 days of incubation of the fish in the presence of carbofuran, the protein contents were recorded to be sufficiently recovered. The fish brain showed two isozymes of AChE moving far apart from each other on polyacrylamide gel. The intensity of AChE bands however, decreased in the pesticide treated fish showing toxic effect of carbofuran at low concentration.

Accounting for the shapes and size distributions of miniature endplate currents

The current model does not account adequately for the characteristics of miniature endplate currents (MEPCs). We do not understand their relatively slow rise, the shape of their rise, their variable and sometimes prolonged decay, and the correlation between amplitude and decay time. If we assume that ACh is released from the vesicle through a pore and that the vesicle enlarges as it takes on additional transmitter, the predictions are more like MEPCs. However, previous measurements showed that after quantal size was increased the vesicles in the terminal were not enlarged. This need not be a problem, because some of the ACh is added to vesicles positioned at the active zones, a process known as second-stage loading. By using the false transmitter precursor monoethylcholine we provide additional evidence for second-stage loading. The distribution of quantal sizes at the junction usually does not follow a normal probability distribution; it is skewed to the right. The skew can be accounted for by a model incorporating second-stage loading in which the vesicles are released randomly, without regard to their ACh content. If the vesicles increase in size when they contain more transmitter, only vesicles at the active zone need swell.

Regulatory Effect of Danggui-Shaoyao-San on Central Cholinergic Nervous System Dysfunction in Mice

Since administration of a powdered extract (TSS) of Danggui-Shaoyao-San (Toki-shakuyaku-san in Japanese) alone to naive mice had no influence on ACh levels in the brain, the present study examined the effect of TSS on the central cholinergic nervous system using mice treated with scopolamine (0.5 mg/kg) or mecamylamine (0.05 mg/kg), which affects the cholinergic nervous system. TSS was suspended in a 5% carboxymethylcellulose solution and mice were orally given single or repeated (twice a day, for 14 days) administration of TSS at 50 or 500 mg/kg. Results on spontaneous locomotor activity showed that (1) single administration of TSS at 50 or 500 mg/kg to naive mice significantly inhibited vertical and horizontal locomotor activities, while repeated administration of TSS at 50 mg/kg significantly stimulated both activities; (2) in mice treated with scopolamine, repeated administration of TSS at 500 mg/kg significantly inhibited the scopolamine-induced increase in locomotor activities, whereas in mice treated with mecamylamine, single or repeated administration of TSS at 50 and 500 mg/kg did not show any influence on the mecamylamine-induced decrease in locomotor activities. Regarding the step-down passive avoidance responses; single administration, but not repeated administration, of TSS at 50 and 500 mg/kg significantly inhibited scopolamine-induced shortening of step-down latency. In mice treated with mecamylamine, TSS did not exert any influence on the step-down latency. As for ACh contents, single or repeated administration of TSS at 50 or 500 mg/kg to naive mice had no influence on the levels of ACh in the cerebral cortex, corpus striatum or hippocampus. However, the levels of brain ACh in mice treated with scopolamine showed a decrease and a single administration of TSS at 500 mg/kg significantly inhibited this scopolamine-induced decrease in ACh levels. These results indicate that TSS ameliorates dysfunction of the central cholinergic nervous system and scopolamine-induced decrease in ACh levels in mouse brain, but has no influence on ACh levels in naive mice. Thus, it suggests that TSS may be a useful therapeutic agent in Alzheimer's disease and senile dementia.

Auto-ignition of [formula omitted], [formula omitted], CH 4/C 3H 8/air and CH 4/CO 2/air using a 11 ignition bomb

The distinction between auto-ignition and hot-surface ignition of a given gas is emphasized. In ideal auto-ignition there is no diffusion of heat or matter. Published information on auto-ignition temperatures (AIT) of multi-component fuels in air is scarce. This also applies to North Sea natural gas, of which CH 4, higher alkanes and CO 2 are essential components. In the present experimental laboratory-scale study, AIT of four types of hydrocarbon mixtures ( CH 4 air , C 3H 8 air , CH 4/C 3H 8/air and CH 4/air/CO 2) have been measured using a 11 ignition bomb. The experimental method ensured that the gas mixtures studied were of known composition and homogeneous in concentration. The gas mixture was admitted to the pre-evacuated ignition bomb in the form of a turbulent jet when the bomb wall had reached the desired temperature. Ignition was recognized as a sudden pressure rise in the bomb a few seconds after the gas flow into the bomb had stopped. The minimum AITs for CH 4 air and C 3H 8 air were found to be 640 °C and 500 °C, respectively. The AIT of CH 4/C 3H 8/air decreased with increasing propane content and total fuel concentration. A fuel concentration region was discovered for which CH 4/C 3H 8/air and C 3H 8 air with the same ratio of propane to oxygen gave the same AIT. Reducing the oxygen content of a CH 4 air mixture by adding CO 2 gave, under the present experimental conditions, a systematic increase of AIT with increasing CO 2 content. The role of the CO 2 was probably essentially that of an inert diluent. It has been known for a long time that the ‘minimum hot-surface ignition temperature’ is not a constant for a given gas mixture, but highly dependent, by several hundred degrees centigrade, on the dynamic state of the gas, the geometry and material of the ignition surface, and the mode of heat supply to the surface. The direct application of AIT values to assess industrial hot-surface ignition risks may therefore be unduly conservative. Consequently there is a need for general mathematical models that can predict minimum ignition temperatures for various practical situations in industry. Such models will have to contain sub-models of ignition chemistry, fluid mechanics and heat and mass transfer.

Levemopamil injection after cerebral oligemia reduces spatial memory deficits in rats

Transient reduction of cerebral blood flow to oligemic levels as produced by bilateral clamping of carotid arteries (BCCA) in pentobarbital anesthetized Wistar rats leads to spatial orientation deficiencies in a water maze test 8–10 days after surgery. These deficiencies are more pronounced in 4-month-old than in 6-week-old animals. Levemopamil [(2S)-2-isopropyl-5-(methylphenethylamino)-2-phenylvaleronitrile hydrochloride], a Ca 2+ channel blocker and 5-HT 2 antagonist, prevents the deficiencies in groups of animals of both ages, even when administered 24 h after the transient vessel occlusion. Levemopamil did not influence the maze performance of sham-operated control rats. Levemopamil, therefore, appears to modulate mechanisms that are altered specifically either by, or as a consequence of, the BCCA procedure. Levemopamil did not influence the altered GABA or ACh content in different vulnerable brain structures following BCCA, showing that the substance acts via additional mechanisms affected by the BCCA procedure.

Acetylcholine synthesis and release following continuous intracerebral administration of NGF in adult and aged Fischer-344 rats

NGF promotes the survival and enhances the neurotransmitter phenotype of basal forebrain and striatal cholinergic neurons in brain of rat. The objective of the present study was to determine whether stimulations of the cholinergic neuronal markers ChAT and high-affinity choline uptake are reflected in enhanced synthesis and release of ACh. Enhancement of ACh release in brain of adult and aged rats could result in increased cholinergic neurotransmission, and altered animal behavior. NGF (1.2 micrograms/d) was administered intracerebroventricularly for 2 weeks by osmotic minipump to male Fischer-344 rats aged 4 and 24 months. Cholinergic neuronal functional parameters were measured in frontal cortex, hippocampus, and striatum. In young adult rats, increased ChAT and choline uptake activities were accompanied by enhanced ACh synthesis, basal and depolarization-induced release of both endogenous and newly synthesized transmitter, with the largest effect generally being observed in striatum. In aged animals, the responses to NGF were less uniform. Whereas the pattern for changes in ChAT activity was similar to that seen in younger animals, choline uptake activity was increased only in frontal cortex and striatum. Coincidentally, ACh synthesis was also increased only in these two brain regions. ACh content of synaptosomes was not affected by age or NGF treatment, and the ACh levels in microwaved samples of striatum and basal forebrain were not affected by NGF treatment. However, profound deficits in both basal and evoked release of newly synthesized ACh were observed in the aged rats. NGF treatment had no significant effect on the basal release of newly synthesized ACh in aged rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation of quantal content to decreased postsynaptic sensitivity at single endplates in alpha-bungarotoxin-treated rats.

1. Rats were injected once every 48 h with alpha-bungarotoxin (alpha BTX) for periods up to 6 weeks. Injections caused weakness of facial muscles which lasted about 8 h. Hemidiaphragms were dissected for biochemical and electrophysiological measurements. 2. In muscles from animals treated for 2-3 weeks with toxin, the binding of 125I-alpha BTX was reduced to 58%, and the ACh content to 81% of control values. Choline acetyltransferase activity was unchanged. ACh release evoked by 3 Hz nerve stimulation was increased to 175% of control values. 3. The use of mu-conotoxin, which specifically blocks muscle action potentials, enabled the recording of full-sized endplate potentials (EPPs) and miniature endplate potentials (MEPPs) at normal muscle membrane potentials (-70 to -80 mV). The amplitude of MEPPs was decreased to 57% in muscles from animals treated for 3 weeks with alpha BTX. The mean of the quantal contents, calculated from the ratio of the corrected EPPs and the MEPPs, was increased to 154%. 4. Within individual muscles of both alpha BTX-treated and control rats, there was an inverse relationship between the quantal content of an endplate and its MEPP amplitude. 5. The MEPP frequency of endplates from control muscles was positively correlated with the quantal content. However, this correlation was not found in alpha BTX-affected muscles. 6. Three hours after a single injection of alpha BTX the amplitude of the MEPPs was reduced to about 60% of control values but no increase of the quantal content was found. During the first few days of alpha BTX treatment the quantal content gradually increased; it reached a plateau between 20 and 30 days. 7. The results suggest the existence of an adaptive mechanism, operating at individual endplates, in which retrograde signals at the motor nerve terminals modulate ACh release when neuromuscular transmission is endangered by block of acetylcholine receptors.

Cholinergic mechanisms in physical dependence on barbiturates, ethanol and benzodiazepines.

The aim of this review is to summarize the effects of acute and chronic treatment with barbiturates, ethanol and benzodiazepines on cholinergic mechanisms in the brains of experimental animals. A single dose of each of these substances reduces the turnover of ACh in the brain. Long-term treatment has the opposite effect; complicated interactions including decreased content of ACh are induced. Barbiturates have been shown to bind stereospecifically to muscarinic and nicotinic receptors in the brain, but this has not been observed for ethanol or the benzodiazepines. The effects on the cholinergic system are affected by the length of treatment and choice of treatment regimen. No effect on cholinergic parameters, such as muscarinic receptors, in the brain is observed on withdrawal of ethanol or barbiturate treatment when the animals are still tolerant towards the substances. The increase in the number of muscarinic receptors observed in several brain regions on withdrawal is seen as a sign of cholinergic supersensitivity. The number of receptors returns to normal when abstinence convulsions have occurred. The assumption of a cholinergic influence is supported by the finding that atropine, given as a single dose on the day of withdrawal of barbital, can prevent the muscarinic receptor changes. Furthermore, long-term barbital or ethanol treatment can induce permanent persistent changes in the cholinergic system in the brain. Cognitive defects and a significant permanent reduction in the content of ACh can be measured in rats which have had long-term barbital treatment. Similarly, a reduced number of muscarinic receptors has been measured in different brain regions of chronic alcoholics. Accumulating data support the role of the cholinergic system in expressing symptoms of physical dependence on barbiturates, ethanol and benzodiazepines as well as in the permanent long-term effects observed after end of treatment.

Effects of tityustoxin and ouabain on release of acetylcholine from slices of cortex from the rat brain and on the acetylcholine content of cytoplasmic and crude vesicular fractions

In this paper, the effects of tityustoxin and ouabain on the release and mobilization of ACh from cytoplasmic and vesicular stores of slices of cortex from the brain of the rat are described. Tityustoxin induced an increase of release of ACh which was time-dependent and this effect was accompanied by a concomitant decrease of the ACh, measured in cytoplasmic and crude vesicular fractions. Unlike tityustoxin, ouabain did not increase the release and synthesis of ACh during a 2 min period of stimulation but later, at 5, 10 and 15 min, ouabain increased the release and synthesis of ACh from incubated slices of cortex. After 10 min, ouabain caused a reduction of the content of ACh from cytoplasmic and crude vesicular fractions.

Acetylcholine synthesis and release is enhanced by dibutyryl cyclic AMP in a neuronal cell line derived from mouse septum

Cholinergic properties of the SN56.B5.G4 cell line derived from the fusion of neurons of the mouse postnatal day 21 septum and the murine neuroblastoma cell line N18TG2 were investigated and correlated with morphological differentiation. In basal serum-containing growth medium, few cells developed neurites. Neurite extension occurred in cells grown for 2 d with forskolin or dibutyryl cAMP (dbcAMP) but not with butyrate. In cells treated with these compounds, the activity of ChAT and ACh content were two- to threefold higher relative to controls. The cells synthesized ACh from choline taken up by the sodium-dependent high-affinity transport. Forskolin-, dbcAMP-, and butyrate-treated cells (but not the controls) were capable of spontaneous and depolarization-evoked ACh release. The results indicate that the morphological and the neurochemical aspects of SN56.B5.G4 cell differentiation are independently regulated.

Effect of Phosphatidylcholine Administration on Choline and Acetylcholine Content in Brain Areas. I.

Although clinical attempts have been made to treat patients with senile dementia using phosphatidylcholine (PC) or acetylcholine (Ach) esterase inhibitors to restore central cholinergic transmission by increasing Ach contents in the brain, definite positive results have yet to be obtained. To investigate further the influence of the systemic administration of PC on brain Ach, we measured choline (Cho) and Ach contents in discrete brain regions of rat by HPLC with an electrochemical detector, following an acute administration of PC. Cho contents increased in the frontal cortex, striatum and substantia innomimata after acute intraperitoneal administration of soybean PC in liposome form. Cho contents were not affected in any region after acute injection of egg PC. Ach contents were not affected significantly in any brain region after acute administration of each PC substance. It thus follows that Cho contents increase by the systemic administration of highly purified PC, and PC may possibly pass the blood brain barrier. However, PC administration is not capable of accelerating Ach synthesis in the brain.

The Influence of Heat Stress on Acetylcholine Content and Its Hydrolyzing Activity in Macroptilium atropurpureum cv. Siratro.

In this work, the changes in ACh-hydrolyzing activity and ACh content in plant tissues of Macroptilium atropurpureum cv. Siratro following leaf wilting and leaf recovery after heat stress and the effects of exogenous ACh, K+ or Ca2+ on detached and heat-stressed leaves to which the primary pulvinus was still attached were determined. The ACh-hydrolyzing activity was 75 nM ACh mg-1 dry weight in the primary pulvinus and 46 nM ACh mg-1 dry weight in the secondary pulvinus, and was 4∼12 fold higher than found in the leaf, petiole, stem or root. Heat stress increased the ACh-hydrolyzing activity about 4 fold and 2 fold in the primary and secondary pulvini, respectively. The ACh-hydrolyzing activity was inhibited about 96% by neostigmine bromide. The content of ACh in the primary and secondary pulvini also changed dramatically within 3 min after heat stress. The changes of ACh content and ACh-hydrolyzing activity in plant tissues were then found to be correlated with leaf drooping and leaf recovery. Additionally, the application of ACh together with K+ or Ca2+ salts remarkably enhanced leaf recovery from wilting in detached and heat-stressed primary pulvinus leaves. The results suggest that ACh may control ion or hormone fluxes regulating the opening of ion channel in pulvini.

P-022 - Effects of eptazocine on changes in the cerebral contents of ACh and choline in mice subjected to cerebral anoxia or ischemia

P-022 - Effects of eptazocine on changes in the cerebral contents of ACh and choline in mice subjected to cerebral anoxia or ischemia

Influence of dietary protein deficiency on EEG neurotransmitters and neurobehaviour after chronic exposure to HCH

The problems of pesticide toxicity is of great importance where malnutrition is a rampant health problem. Rats fed on synthetic diet (21% & 5% Casein) were given orally 50 mg/Kg Hexachlorocyclohexane (HCH) for three months period. Neurotransmitters measured from the discrete areas of brain showed significant increase of dopamine (DA) and decrease in the levels of 5‐Hydroxytryptamine (5‐HT) and norepinephrine (NE). Acetylcholine (Ach) content in cerebral cortex was increased. Behavioural observations included distance travelled, resting time, ambulatory and Stereotypie movement showed marked changes on optovarimax, while a significant increase (p < 0.001) was noticed in vertical movement of the rats exposed to HCH. Electroencephalograph records showed bursts of spikes with increased wave frequency.

Muscle acetylcholinesterase adapts to compensatory overload by a general increase in its molecular forms

We have investigated the impact of compensatory overload on the content of acetylcholinesterase (AChe) molecular forms in the rat fast-twitch medial gastrocnemius (MG). Overload was induced by way of a bilateral tenotomy of the MG's functional synergists coupled to a daily walking training program (15 m/min, 30% incline, up to 60 min per session, 12-18 wks). This latter condition ensured that the MG were used on a regular basis. In comparison to control values, overloaded MG showed 25 and 19% increases (P less than 0.05) in muscle wet weight and protein concentration, respectively. The content in AChe (activity per muscle) was also increased in these MG (28%, P less than 0.05). Sedimentation analyses revealed a general elevation in the content of AChe molecular forms, with A8, G2, and G1 displaying significant changes (35-42%, P less than 0.05). In a second group of rats, daily running training (27 m/min, 30% incline, using the same timetable) was supplemented to the compensatory overload. In this group, the additional running training led to a greater hypertrophic response as attested to by increases (P less than 0.05) in the MG wet weight (41%) and protein concentration (35%) in comparison to controls. However, total AChe content of these muscles was increased to an extent similar to that observed in the MG subjected only to compensatory overload (24%, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Significant correlation between cerebrospinal fluid and brain levels of norepinephrine, serotonin and acetylcholine in anesthetized rats

The present study was undertaken to determine cerebrospinal fluid (CSF) and brain levels of norepinephrine (NE), serotonin (5-HT) and their metabolites--3,4-dihydroxyphenylacetic acid (DOPAC), 4-hydroxy-3-methoxyphenylacetic acid (HVA) and 5-hydroxyindole-3-acetic acid (5-HIAA)--in rats pretreated with 6-hydroxydopamine (6-OHDA) or 5,7-dihydroxytryptamine (5,7-DHT). In the 6-OHDA pretreated rats, both CSF and brain concentrations of NE, DOPAC and HVA sustained significant decreases as compared with those in non-treated rats. Positive and significant correlations between CSF and brain levels were observed in respect to NE, DOPAC and HVA. In 5,7-DHT pretreated rats, both CSF and brain concentrations of 5-HT and 5-HIAA were significantly decreased. A positive and significant correlation between CSF and brain levels in respect to 5-HT and 5-HIAA was observed. Further studies were carried out to determine ACh levels of both the CSF and the brain in microspheres (MS)-treated rats, which are used as a model of microembolization. The CSF ACh concentrations in MS-treated groups were significantly decreased as compared with those in non-treated rats. The brain ACh contents also tended to decrease in this group. A positive and significant correlation was observed between CSF and brain levels of ACh. These findings suggest that NE, 5-HT and ACh concentrations in the CSF are direct indications of central noradrenergic, serotonergic and cholinergic nerve activity, respectively.

The mechanism of low susceptibility to stress in gastric lesions of spontaneously hypertensive rats

The mechanism of low susceptibility to stress in gastric lesion formation in spontaneously hypertensive rats (SHR) was investigated focusing on the sympathetic and parasympathetic nervous systems. In the gastric tissues of SHR, norepinephrine (NE) and dopamine (DA) contents were higher, while acetylcholine content and choline acetyltransferase activity were lower than those of Wistar-Kyoto rats (WKY). Water-immersion restraint induced gastric lesions frequently in WKY (ulcer indices: 52±7mm 2) but less frequently in SHR (ulcer indices: 3±1mm 2). Although NE content decreased in both SHR and WKY as a result of water-immersion restraint, it remained higher in SHR than in WKY. ACh content decreased by the procedure in WKY but not in SHR. DA content was increased by the procedure in all gastric regions of SHR. The gastric lesions induced in SHR were aggravated by pretreatment with 6-hydroxydopamine, an agent for chemical sympathectomy, following decreases of NE and DA contents. These results indicate that the relative sympathetic hyperfunction, parasympathetic hypofunction and dopaminergic mechanism in the stomach contribute to the prevention of gastric lesion formation in SHR.

Rostral medullary cholinergic mechanisms and chronic stress-induced hypertension

This work was designed to study the relationship between the cholinergic mechanisms in the rostral ventrolateral medulla (rVLM) and the incidence of hypertension induced by chronic stress. Under anaesthetized conditions, bilateral microinjection of scopolamine (1.18 nmol/site) into the rVLM produced a much greater depressor response in chronic stress-induced hypertensive rats than in normotensive rats. Similar bradycardic effects were observed in both the normotensive and the hypertensive rats when scopolamine was injected into the rVLM. Acetylcholine (Ach) content and choline acetyltransferase (ChAT) activity in rostral medulla were determined by radioimmunoassay both in the normotensive and the hypertensive rats. Ach content and ChAT activity increased significantly in the hypertensive rats, and such increase mainly occurred within the ventral part of the rostral medulla. These results suggest that the cholinergic mechanisms in the rVLM may be activated during chronic stress and such activation may be involved in the pathogenesis of the hypertension induced by chronic stress.

Alteration of metabolism of acetylcholine induced by 2-deoxy- d-glucose in the gastroduodenum of the rat

2-Deoxy- d-glucose (2-DG) administered intraperitoneally, dose-dependently increased the secretion of gastric acid, and the changes were comparable with those on the activity of choline acetyltransferase (CAT) and acetylcholinesterase (AChE) in the stomach. Double-reciprocal plot analysis of the increased activity of CAT and AChE, induced by 2-DG, showed that the changes were due to the increase of V max, with no change in the k m-value for the substrates. The uptake of [ 3H]choline and subsequent synthesis of [ 3pH]ACh was observed in the forestomach, corpus and antrum of the stomach and in the duodenum. 2-Deoxy- d-glucose significantly increased the uptake of [ 3H]choline and synthesis of [ 3pH]ACh in every region of the stomach and in the duodenum, in a dose-dependent manner. The increase of secretion of gastric acid, induced by 2-DG paralleled that of uptake of [ 3H]choline and synthesis of [ 3H]ACh at an early stage. The conversion of [ 3H]choline taken up to [ 3H]ACh was negligibly influenced by 2-DG. Neither the content of ACh and choline, nor the turnover rate of ACh, were changed by administration of 2-DG. 2-Buten-4-olide (2-B40), which inhibits the activity of the vagus nerve through the central nervous system, prevented 2-DG-induced uptake of [ 3H]choline and subsequent synthesis of [ 3H]ACh, as well as the increase in secretion of gastric acid. These results suggest that the uptake of [ 3H]choline and subsequent synthesis of [ 3H]ACh are closely related to the neuronal activity of the vagus nerve, and that cholinergic neuronal activity is dependent upon quantitative changes of metabolism of ACh in the gastroduodenum.