Distribution Of Choline Acetyltransferase Research Articles

GAPT regulates cholinergic dysfunction and oxidative stress in the brains of learning and memory impairment mice induced by scopolamine

BackgroundCholinergic dysfunction and oxidative stress are the crucial mechanisms of Alzheimer's disease (AD). GAPT, also called GEPT (a combination of several active components extracted from the Chinese herbs ginseng, epimedium, polygala and tuber curcumae) or Jinsiwei, is a patented Chinese herbal compound, has been clinically widely used to improve learning and memory impairment, but whether it can play a neuroprotective role by protecting cholinergic neurons and reducing oxidative stress injury remains unclear.MethodsMale ICR mice were intraperitoneally injected with scopolamine (3 mg/kg) to establish a learning and memory disordered model. An LC‐MS method was established to study the chemical compounds and in vivo metabolites of GAPT. After scopolamine injection, a step‐down passive‐avoidance test (SDPA) and a Y maze test were used to estimate learning ability and cognitive function. In addition, ELISA detected the enzymatic activities of acetylcholinesterase (AChE), acetylcholine (ACh), choline acetyltransferase (ChAT), malondialdehyde (MDA), glutathione peroxidase (GPX), and total superoxide dismutase (T‐SOD). The protein expressions of AChE, ChAT, SOD1, and GPX1 were observed by western blot, and the distribution of ChAT, SOD1, and GPX1 was observed by immunohistochemical staining.ResultsAfter one‐half or 1 month of intragastric administration, GAPT can ameliorate scopolamine‐induced behavioral changes in learning and memory impaired mice. It can also decrease the activity of MDA and protein expression level of AChE, increase the activity of Ach, and increase activity and protein expression level of ChAT, SOD, and GPX in scopolamine‐treated mice. After one and a half month of intragastric administration of GAPT, echinacoside, salvianolic acid A, ginsenoside Rb1, ginsenoside Rg2, pachymic acid, and beta asarone could be absorbed into mice blood and pass through BBB.ConclusionsGAPT can improve the learning and memory ability of scopolamine‐induced mice, and its mechanism may be related to protecting cholinergic neurons and reducing oxidative stress injury.

Neuroanatomical organization of the cholinergic system in the central nervous system of a basal actinopterygian fish, the senegal bichirPolypterus senegalus

Polypterid bony fishes are believed to be basal to other living ray-finned fishes, and their brain organization is therefore critical in providing information as to primitive neural characters that existed in the earliest ray-finned fishes. The cholinergic system has been characterized in more advanced ray-finned fishes, but not in polypterids. In order to establish which cholinergic neural centers characterized the earliest ray-finned fishes, the distribution of choline acetyltransferase (ChAT) is described in Polypterus and compared with the distribution of this molecule in other ray-finned fishes. Cell groups immunoreactive for ChAT were observed in the hypothalamus, the habenula, the optic tectum, the isthmus, the cranial motor nuclei, and the spinal motor column. Cholinergic fibers were observed in both the telencephalic pallium and the subpallium, in the thalamus and pretectum, in the optic tectum and torus semicircularis, in the mesencephalic tegmentum, in the cerebellar crest, in the solitary nucleus, and in the dorsal column nuclei. Comparison of the data within a segmental neuromeric context indicates that the cholinergic system in polypterid fishes is generally similar to that in other ray-finned fishes, but cholinergic-positive neurons in the pallium and subpallium, and in the thalamus and cerebellum, of teleosts appear to have evolved following the separation of polypterids and other ray-finned fishes.

A comparison of the distribution and morphology of ChAT-, VAChT-immunoreactive and AChE-positive neurons in the thoracolumbar and sacral spinal cord of the pig

Present knowledge concerning the organization of cholinergic structures of the spinal cord has been derived primarily from studies on small laboratory animals, while there is a complete lack of information concerning its structure in the pig. In the present study we employed choline acetyltransferase (ChAT) and vesicular acetylcholine transporter (VAChT) immunocytochemistry and acetylcholinesterase (AChE) histochemistry to identify the cholinergic neuronal population in the thoracolumbar and sacral spinal cord of the pig. The distribution of ChAT-, VAChT- and AChE-positive cells was found to be similar. Distinct groups of cholinergic neurons were observed in the gray matter of the ventral horn, intermediolateral nucleus, intermediomedial nucleus as well as individual stained cells were found in the area around the central canal and in the base of the dorsal horn. Double staining confirmed complete colocalization of ChAT with AChE in the ventral horn and intermediolateral nucleus although in the intermediomedial nucleus only 64% of the AChE-positive neurons expressed ChAT-immunoreactivity, indicating unique, region restricted, diversity of ChAT and AChE staining. Our results revealed details concerning spatial distribution and morphological features of the cholinergic neurons in the thoracolumbar and sacral spinal cord of the pig. We also found that the pattern of distribution of cholinergic neurons in the porcine spinal cord shows great similarity to the organization of the cholinergic system in other mammalian species studied.

The psoriasis variant palmoplantar pustulosis can be improved after cessation of smoking

The psoriasis variant palmoplantar pustulosis can be improved after cessation of smoking

Distribution of choline acetyltransferase and NADPH diaphorase in the spinal cord of the pigeon.

Acetylcholine is the neurotransmitter of somatic and autonomic motor systems of the spinal cord. However, there are also intrinsic cholinergic systems which have modulatory functions. Modulatory functions have also been assigned to nitric oxide (NO). Acetylcholine is synthesized by choline acetyltransferase and NO by nitric oxide synthase, which is a NADPH diaphorase. The distribution of both enzymes in the mammalian spinal cord is well known. However, there is a lack of comparative data in avian species. Therefore, the distribution of both enzymes in the spinal cord of the pigeon was studied using histochemical and immunohistochemical methods. Aside from somatic motor neurons and autonomic preganglionic neurons choline acetyltransferase-immunoreactivity was found throughout the spinal cord in lamina III of the superficial dorsal horn and near the central canal. The location of choline acetyltransferase-positive preganglionic neurons in the centrally located column of Terni and the lack of an intermediolateral column typical of the mammalian spinal cord can be confirmed. In lumbosacral segments the axons of centrally located cholinergic neurons crossed to the contralateral side to form a tract in the ventral funiculus, which then innervates the contralateral grey substance. A dense band of NADPH diaphorase staining was found in lamina II and in centrally located neurons of all segments. Part of the centrally located neurons double-labelled for choline acetyltransferase and NADPH diaphorase. In contrast to mammals, preganglionic neurons labelled only weakly for NADPH diaphorase. Altogether, despite the divergent evolution of both classes of vertebrate intrinsic modulatory choline acetyltransferase and NADPH diaphorase systems of birds seem to be largely similar to those of the mammalian spinal cord.

Occurrence, co-occurrence and topographic distribution of choline acetyl transferase, Met-enkephalin and neurotensin in the stellate ganglion of the cat.

The presence of the classical ganglionic transmitter acetylcholine (ACh), its occurrence and possible co-occurrence with the neuromodulator peptides methionine enkephalin (Met-ENK) and neurotensin (NT), as well as the possible coexistence of these peptides in the preganglionic axon terminals of the cat stellate ganglia were investigated with light and confocal microscopy using immunofluorescence. Choline acetyltransferase (ChAT), Met-ENK, and NT immunoreactivity was detected with light microscopy in axon terminals near tyrosine hydroxylase (TH) immunoreactive (IR) cells. Cell bodies immunopositive for ChAT or Met-ENK were also detected and were TH-negative or TH-positive. Denervation by sectioning preganglionic axons produced two effects: the almost complete elimination of IR fibers and an increase in the number of ChATIR and Met-ENKIR cell bodies, together with the appearance of NTIR cell bodies. Preganglionic ChATIR fibers and boutons form a dense network throughout the entire ganglion, with a homogeneous regional distribution. ChAT, Met-ENK, and NT are essentially stored in different nerve endings, although a low level of co-occurrence was detected. NTIR and Met-ENKIR networks of boutons were observed to have independent and somewhat complementary regional distributions. Further analysis with simultaneous triple labeling for NT, Met-ENK, and TH, and confocal microscopy showed fibers and boutons containing Met-ENK or NT reached distinct neurons separately, or both converge onto the same cells. This finding suggests that modulation (the facilitation-inhibition balance) of ganglionic transmission is achieved mainly by the selective and complementary innervation of boutons containing NT (facilitation) and Met-ENK (inhibition) and only rarely by terminals which coexpress both peptides.

Prenatal exposure to methylazoxymethanol acetate in the rat alters neurotrophin levels and behavior: considerations for neurodevelopmental diseases

We did a single injection of methylazoxymethanol acetate (MAM) in pregnant rats on gestational day (GD) 11 or 12 to investigate the long-lasting effects of early entorhinal cortex (EC) and hippocampus maldevelopment on behavior, brain nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) levels, and the neurotrophin receptor p75 and choline acetyltransferase (ChAT) immunoreactivity. Adult animals treated with MAM had compromised EC development and showed changes in locomotion and displacement activities. In addition, rats treated on GD 12 had increased concentration of NGF and BDNF in the EC and hippocampus if compared to control rats. Prenatal MAM administration did not affect significantly p75 and ChAT distribution in the EC and septum. Results are discussed in reference to the neurodevelopmental hypothesis of psychiatric disorders.

The cat neostriatum: relative distribution of cholinergic neurons versus serotonergic fibers.

The distribution of choline acetyltransferase (ChAT)-containing neurons and serotonin (5-HT)-containing nerve fibers in the cat neostriatum was investigated by use of immunohistochemical techniques. Both ChAT- and 5-HT-staining techniques were applied to alternate brain sections, thereby allowing a precise comparison of the distribution pattern of ChAT-immunopositive cells (ChAT cells) and 5-HT-immunopositive fibers (5-HT fibers). In the neostriatum, ChAT cells were strongly stained throughout their cell bodies and proximal (first-order) dendrites. The majority of them were multipolar cells with a soma diameter of 20-50 microm (long axis)x10-30 microm (short axis). In the caudate nucleus, ChAT cells were evenly and diffusely distributed except for the dorsolateral region of its rostral half, in which latter region they were distributed in loosely formed clusters. In the rostral portion of the putamen, the density of ChAT-cell distribution was like that in the medial region of the caudate nucleus. In contrast, this distribution was more dense in the caudomedial region of the putamen, adjacent to the globus pallidus. 5-HT fibers in the neostriatum were dark-stained, of quite fine diameter (<0.6 microm), and they contained small, round varicosities (diameter, usually 0.5-1.0 microm, but some >1.0 microm). Such 5-HT fibers were distributed abundantly throughout the caudate nucleus and putamen. In the rostrocaudal portion of the caudate nucleus, their density was high in its dorsal and ventral components, and low in the middle component. Throughout the putamen, 5-HT fibers were distributed homogeneously in the mediolateral and dorsoventral directions. In the caudal portion of the putamen adjacent to the globus pallidus, the 5-HT fibers had a higher density while maintaining their homogenous distribution pattern. In the two main divisions of the striatum, the so-called 'patch' (acetylcholinesterase (AChE)-poor) and 'matrix' (AChE-rich) compartments, there was a near-even distribution of 5-HT fibers and terminals. The above results suggest that the 5-HT-dominated, raphe-striatal pathway is optimally arranged for modulating the activity of both the intrinsic and the projection neurons of the neostriatum.

Choline acetyltransferase detection in normal and denervated electrocyte from Electrophorus electricus (L.) using a confocal scanning optical microscopy analysis.

Acetylcholine is the neurotransmitter responsible for the transmission of impulses from cholinergic neurons to cells of innervated tissues. Its biosynthesis is catalyzed by the enzyme Choline acetyltransferase that is considered to be a phenotypically specific marker for cholinergic system. It is well known that the regulation of Choline acetyltransferase activity under physiological and pathological conditions is important for development and neuronal activities of cholinergic functions. We observed the distribution of Choline acetyltransferase in sections from the normal and denervated main electric organ sections of Electrophorus electricus (L.) by immunofluorescence using a anti-Choline acetyltransferase antibody. The animals were submitted to a surgical procedure to remove about 20 nerves and after 30 and 60 days, they were sacrificed. After 30 days, the results from immunohistochemistry demonstrated an increase on the Choline acetyltransferase distribution at denervated tissue sections when compared with the sections from the normal contralateral organ. A very similar labeling was observed between normal and denervated tissue sections of the animals after 60 days. However, Choline acetyltransferase activity (nmolesACh/ min/ mg of protein) in extracts obtained from electrocyte microsomal preparation, estimated by Fonnun's method (Fonnun 1975), was 70% lower in the denervated extracts.

Chronic antipsychotic treatment selectively alters nerve growth factor and neuropeptide Y immunoreactivity and the distribution of choline acetyl transferase in rat brain regions

Neuropeptides and neurotrophins play a number of roles in the central nervous system (CNS). Nerve growth factor (NGF), the first characterized member of the family of neurotrophins, influences the synthesis of some neuropeptides, including neuropeptide Y (NPY), a peptide amply expressed in the CNS, interacting with catecholamines and modifying behaviour. In this study we investigated whether antipsychotic treatment affects the constitutive levels of NGF-, NPY- and choline acetyl transferase (ChAT)-like immunoreactivities (-LI) in the CNS. Rats were fed food supplemented with haloperidol (1.15 mg/100 g food), risperidone (1.15 or 2.3 mg/100 g food), or vehicle. After 29 d treatment animals were sacrificed with focused high-energy microwave irradiation for radioimmunoassay (RIA) of NPY-LI, by decapitation for analysis of NGF, and by perfusion for immunocytochemistry. Haloperidol and risperidone elevated NGF-LI concentrations in the hypothalamus but decreased NGF-LI in the striatum and hippocampus. In contrast, antipsychotics did not alter NPY-LI in the striatum. Haloperidol increased NPY-LI concentration in the occipital cortex, while risperidone increased NPY-LI in the occipital cortex, hippocampus, and hypothalamus. Significant decreases in ChAT immunoreactivity in large-size neurons following both haloperidol and risperidone treatments in the septum as well as Meynert's nucleus were observed. Our findings demonstrate that antipsychotic drugs alter the regional brain levels of NGF-LI, NPY-LI and ChAT-LI and raise the possibility that these effects are implicated in their pharmacological and therapeutic properties.

The distribution of choline acetyltransferase- and acetylcholinesterase-like immunoreactivity in the palmar skin of patients with palmoplantar pustulosis.

The distribution of choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) in involved skin in patients with palmoplantar pustulosis (PPP) and in normal palmar skin in healthy non-smokers and smokers has been studied by immunohistochemistry, especially in relation to the sweat gland apparatus. The sweat gland and its duct showed ChAT- and AChE-like immunoreactivity (LI) of varying intensity in all three groups and with stronger reactivity than in the epidermis. ChAT-LI was present in the coil and in the duct except in the corneal layer. Smokers and patients with PPP displayed significantly fewer ChAT+ acrosyringia than non-smokers. In the patients with PPP, the granulocytes in the pustules and in the papillary dermis displayed ChAT-LI. Western blot analysis of granulocytes from peripheral blood from healthy donors confirmed the presence of ChAT-like proteins in large amounts in neutrophils and small amounts in eosinophils. AChE-LI of varying intensity was found in all parts of the sweat gland apparatus in all three groups. The strongest AChE-LI in the acrosyringia was seen in the lowest part of the stratum corneum, where the PPP pustules are located. No significant differences in staining pattern or intensity were found between the coils, nerve fibres surrounding the coils or ducts. The number of mast cells in the papillary dermis was about four times larger in the patients with PPP than in the control subjects. AChE-LI was observed in about 25% of the mast cells in non-smoking control subjects and in patients with PPP, but only in 10% of those in the smoking control subjects. Our findings indicate that the (non-neuronal) cholinergic system may be involved in cutaneous inflammatory processes.

Distribution of choline acetyltransferase (ChAT) immunoreactivity in the central nervous system of a chondrostean, the siberian sturgeon (Acipenser baeri).

All studies to date of cholinergic systems of bony fishes have been done in teleosts. To gain further insight into the evolution of the cholinergic systems of bony fishes, we have studied the brain of a chondrostean fish, the Siberian sturgeon (Acipenser baeri, Brandt), by using an antibody against choline acetyltransferase (ChAT). This study showed the presence of ChAT-immunoreactive (ChAT-ir) neurons in the preoptic region (parvocellular and magnocellular preoptic nuclei and suprachiasmatic nucleus), the periventricular and tuberal hypothalamus, the saccus vasculosus, the dorsal thalamus, and the habenula. The mesencephalic tegmentum contained ChAT-ir cells in the torus semicircularis and torus lateralis. The isthmus contained several cholinergic populations: the nucleus isthmi, the lateral nucleus of the valvula, the secondary visceral nucleus, and the dorsal tegmental nucleus. The motor neurons of the cranial nerves and the spinal motor column were strongly immunoreactive. The medial (sensory) trigeminal nucleus also contained a ChAT-ir neuronal population. The distribution of ChAT-ir neurons in the sturgeon brain showed some notable differences with that observed in teleosts, such as the absence of cholinergic cells in the telencephalon and the optic tectum. Several brain regions were richly innervated by ChAT-ir fibers, particularly the telencephalon, optic tectum, thalamus, posterior tubercle, and interpeduncular nucleus. The hypothalamo-hypophyseal tract, the tract of the saccus vasculosus, the fasciculus retroflexus, and an isthmo-mesencephalo-thalamic tract were the most conspicuous cholinergic bundles. Comparative analysis of these results suggests that teleosts have conserved most traits of the cholinergic system of the sturgeon, having acquired new cholinergic populations during evolution.

Distribution of choline acetyltransferase (ChAT) immunoreactivity in the brain of the adult trout and tract-tracing observations on the connections of the nuclei of the isthmus.

The distribution of cholinergic neurons and fibers was studied in the brain and rostral spinal cord of the brown trout and rainbow trout by using an antiserum against the enzyme choline acetyltransferase (ChAT). Cholinergic neurons were observed in the ventral telencephalon, preoptic region, habenula, thalamus, hypothalamus, magnocellular superficial pretectal nucleus, optic tectum, isthmus, cranial nerve motor nuclei, and spinal cord. In addition, new cholinergic groups were detected in the vascular organ of the lamina terminalis, the parvocellular and magnocellular parts of the preoptic nucleus, the anterior tuberal nucleus, and a mesencephalic tegmental nucleus. The presence of ChAT in the magnocellular neurosecretory system of trout suggests that acetylcholine is involved in control of hormone release by neurosecretory terminals. In order to characterize the several cholinergic nuclei observed in the isthmus of trout, their projections were studied by application of 1,1;-dioctadecyl-3,3,3;, 3;-tetramethylindocarbocyanine perchlorate (DiI) to selected structures of the brain. The secondary gustatory nucleus projected mainly to the lateral hypothalamic lobes, whereas the nucleus isthmi projected to the optic tectum and parvocellular superficial pretectal nucleus, as previously described in other teleost groups. In addition, other isthmic cholinergic nuclei of trout may be homologs of the mesopontine system of mammals. We conclude that the cholinergic systems of teleosts show many primitive features that have been preserved during evolution, together with characteristics exclusive to the group.

Distribution of acetylcholinesterase and choline acetyltransferase in the main and accessory olfactory bulbs of the hedgehog (Erinaceus europaeus).

The distribution of cholinergic markers was studied in the main olfactory bulb (MOB) and accessory olfactory bulb (AOB) of the western European hedgehog (Erinaceus europaeus) by using choline acetyltransferase (ChAT) immunocytochemistry and acetylcholinesterase (AChE) histochemistry. A dense network of AChE-containing and ChAT-immunoreactive fibers was observed innervating all layers of the MOB except the olfactory nerve layer, where neither AChE- nor ChAT-labeled elements were found. The highest density of AChE- and ChAT-positive axons was found in the glomerular layer (GL)/external plexiform layer (EPL) boundary, and in the internal plexiform layer. This general distribution pattern of ChAT- and AChE-stained axons resembled the distribution pattern found in rodents. Nevertheless, some interspecies differences, such as the lack of atypical glomeruli in the hedgehog, were also found. In addition to fibers, a population of noncholinergic and presumably cholinoceptive AChE-active neurons was observed in the hedgehog. All mitral and tufted cells of the hedgehog MOB showed a dark AChE staining unlike previous observations in the mitral and tufted cells of rodents. As in other species previously reported, subpopulations of external tufted cells and short-axon cells were also AChE-active. Finally, a population of small AChE-containing cells was observed in the EPL of the hedgehog MOB. The size, shape, and location of these cells coincided with those of satellite and perinidal cells, two neuronal types described previously in the EPL of the hedgehog and not present in the rodent MOB. The AOB of the hedgehog showed a distribution of AChE- and ChAT-positive fibers similar to the rodent AOB. Nevertheless, a heterogeneous innervation of vomeronasal glomeruli by bundles of AChE- and ChAT-labeled axons found in the hedgehog has not been previously found in any other species. As in the MOB, all mitral cells in the AOB showed a strong AChE activity. These results demonstrate some similarities but also important differences between the distribution of ChAT and AChE in the MOB and AOB of rodents and this primitive mammalian. These variations may indicate a different organization of the cholinergic modulation of the olfactory information in the insectivores.

Distribution of choline acetyltransferase (ChAT) immunoreactive nerve fibers in the nasal mucosa; especially in the respiratory epithelium

The distribution and morphological construction of cholinergic nerve fibers in the respiratory nasal mucosa of the rat and human were investigated using choline acetytransferase (ChAT) activities by means of light microscopy, confocal laser scanning microscopy and electron microscopy. It was observed that ChAT-immunoreactive (IR) nerve fibers were distributed to form fine varicosities around the blood vessels and seromucous glands under the epithelium and at the basement membrane and within the epithelium. Electron microscopy showed that the ChAT-IR nerve fibers within the epithelium terminated as free nerve endings. Some of them were in close contact with goblet cells. The distribution of ChAT immunoreactive fibers resembled that of vasoactive intestinal polypeptide-IR nerve fibers.

Cholinergic innervation of the primate hippocampal formation: II. Effects of fimbria/fornix transection.

The distribution of choline acetyltransferase (ChAT)-immunoreactive and acetylcholinesterase (AChE)-positive fibers and terminals was analyzed in the hippocampal formation of macaque monkeys subjected to transection of the fimbria/fornix. Cases with either unilateral or bilateral transections were prepared, with post transection survival times ranging from 2 weeks to 1.5 years. The fimbria/fornix transection resulted in a dramatic decrease in the number of cholinergic fibers in most regions of the hippocampal formation. Some hippocampal regions, however, showed relatively greater sparing of ChAT- or AChE-positive fibers. In practically all regions of the hippocampal formation, residual AChE-positive fibers were more abundant than ChAT-immunoreactive fibers. In animals with unilateral lesions, the distribution patterns and density of AChE and ChAT staining on the side contralateral to the lesion were generally similar to those of sections from unlesioned control brains. The largest decreases in the densities of positive fibers were observed in the dentate gyrus, CA3 and CA2 fields of the hippocampus, subiculum, parasubiculum, and medial and caudal parts of the entorhinal cortex. Fibers were relatively better preserved in the rostral or uncal portion of the hippocampus and dentate gyrus and in the rostral portion of the entorhinal cortex. The presubiculum demonstrated remarkable sparing that contrasted with the almost complete loss of fibers in the parasubiculum. Interestingly, animals killed approximately 1.5 years after the fornix transection showed essentially the same pattern of fiber loss as the cases with shorter survival periods. This indicates that the residual ChAT-immunoreactive fibers, many of which reach the hippocampal formation through a ventral cholinergic pathway, are not capable of reinnervating the denervated portions of the hippocampal formation. This appears to distinguish the monkey from the rat, for which substantial sprouting and reinnervation of cholinergic fibers have been reported after similar lesions.

Distribution of choline acetyltransferase and acetylcholinesterase in vocal control nuclei of the budgerigar (Melopsittacus undulatus).

The present study used histochemical methods to map the distributions of choline acetyl transferase (ChAT) and acetylcholinesterase (AChE) in the vocal control nuclei of a psittacine, the budgerigar (Melopsittacus undulatus). The distributions of ChAT and AChE in budgerigars appeared similar to that in oscine songbirds despite evidence that these systems have evolved independently. The magnicellular nucleus of the lobus parolfactorius in budgerigars, like the area X in songbirds, contained many ChAT labeled somata, fibers, and varicosities and stained densely for AChE. In contrast, the robust nucleus of the archistriatum (RA) and the supralaminar area of the frontal neostriatum in budgerigars, like the RA and the magnicellular nucleus of the neostriatum (MAN) in songbirds, respectively, contained few or no ChAT labeled somata, fibers, and varicosities and stained lightly for AChE. The central nucleus of the lateral neostriatum in budgerigars, like the higher vocal center (HVC) in songbirds, contained no ChAT labeled somata, moderate densities of ChAT labeled fibers and varicosities, and moderate levels of AChE staining. Two nuclei, the oval nucleus of the hyperstriatum ventrale (HVo) and the oval nucleus of the anterior neostriatum (NAo), contained no ChAT labeled somata, dense ChAT labeled fibers and varicosities, and moderate to high levels of AChE staining. The HVo and the NAo have no counterparts in songbirds but may be important vocal control nuclei in the budgerigar. Cholinergic enzymes are also described in other regions which may be involved in budgerigar vocal behavior, including the basal forebrain, the torus semicircularis, and the hypoglossal nuclei (nXII).

Distribution of choline acetyltransferase and acetylcholinesterase in vocal control nuclei of the budgerigar (Melopsittacus undulatus)

The present study used histochemical methods to map the distributions of choline acetyl transferase (ChAT) and acetylcholinesterase (AChE) in the vocal control nuclei of a psittacine, the budgerigar (Melopsittacus undulatus). The distributions of ChAT and AChE in budgerigars appeared similar to that in oscine songbirds despite evidence that these systems have evolved independently. The magnicellular nucleus of the lobus parolfactorius in budgerigars, like the area X in songbirds, contained many ChAT labeled somata, fibers, and varicosities and stained densely for AChE. In contrast, the robust nucleus of the archistriatum (RA) and the supralaminar area of the frontal neostriatum in budgerigars, like the RA and the magnicellular nucleus of the neostriatum (MAN) in songbirds, respectively, contained few or no ChAT labeled somata, fibers, and varicosities and stained lightly for AChE. The central nucleus of the lateral neostriatum in budgerigars, like the higher vocal center (HVC) in songbirds, contained no ChAT labeled somata, moderate densities of ChAT labeled fibers and varicosities, and moderate levels of AChE staining. Two nuclei, the oval nucleus of the hyperstriatum ventrale (HVo) and the oval nucleus of the anterior neostriatum (NAo), contained no ChAT labeled somata, dense ChAT labeled fibers and varicosities, and moderate to high levels of AChE staining. The HVo and the NAo have no counterparts in songbirds but may be important vocal control nuclei in the budgerigar. Cholinergic enzymes are also described in other regions which may be involved in budgerigar vocal behavior, including the basal forebrain, the torus semicircularis, and the hypoglossal nuclei (nXII). © 1996 Wiley-Liss, Inc.

Cholinergic innervation of the primate hippocampal formation. I. Distribution of choline acetyltransferase immunoreactivity in the Macaca fascicularis and Macaca mulatta monkeys.

The cholinergic innervation of the hippocampal formation of Macaca fascicularis (cynomolgus) and Macaca mulatta (rhesus) monkeys was investigated by immunohistochemical procedures using a monoclonal antibody directed against choline acetyltransferase. The distribution of choline acetyltransferase in the monkey demonstrated both similarities and differences with the staining patterns observed in the rat or with acetylcholinesterase in the monkey. While both of these latter preparations demonstrated labeled cells, for example, no choline acetyltransferase labeled neurons were observed in the monkey hippocampal formation. Choline acetyltransferase activity was restricted to fibers which varied in thickness and number of varicosities and in their regional and laminar distribution. The highest densities of labeled fibers were observed in the uncal portion of the hippocampus, in the parasubiculum, and in the entorhinal cortex; the lowest densities of labeled fibers were observed in CA1 and in midrostrocaudal levels of the dentate gyrus. In the dentate gyrus, immunoreactive fibers were densely distributed in the molecular layer and in an infragranular plexus. One of the few striking noticeable interspecies differences was observed in the dentate gyrus. In the rhesus monkey, labeled fibers in the molecular layer were divided into a superficial denser and an inner lighter lamina, whereas in M. fascicularis, the cholinergic fibers were distributed more homogeneously throughout the molecular layer. In the hippocampus proper, there was a progressive decrease in the density of ChAT-immunoreactive fibers from CA3/CA2 into CA1. The subiculum also demonstrated modest labeling which was nonetheless higher than in CA1; the border of these fields demonstrated increased fiber labeling. The density of choline acetyltransferase staining was high in the presubiculum and parasubiculum. In the entorhinal cortex, a relatively clear boundary was observed between the more heavily stained superficial layers (I, II, and III) and the more weakly labeled deep layers (V and VI), especially in the intermediate and caudal fields. A transverse decreasing gradient was observed with the densest plexus of cholinergic fibers found in the medially situated olfactory field of the entorhinal cortex and the lowest density in the laterally located caudal and lateral fields.

Choline acetyltransferase (ChAT) immunoreactivity in a sub-population of mammalian intestinal endocrine cells.

1. The distribution of choline acetyltransferase (ChAT) in rat and guinea-pig intestine has been analysed using an indirect immunofluorescence technique. 2. ChAT immunoreactivity was apparent in nerve fibres and cell bodies of the myenteric and submucous plexus and in fibres throughout the muscle coats and the mucosa. 3. Staining was also evident in a sub-population of mucosal endocrine cells in the small intestine, implying the existence of this enzyme and its product (acetylcholine) in these cells. 4. These data are consistent with previous observations on the distribution of ChAT activity in mammalian intestine.