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Biomedical subjects

L L Butcher

Publications and source records attributed to L L Butcher.

At least 91 records · Page 5Linked to original sources
PubMed1977

Morphological characteristics of acetylcholinesterase-containing neurons in the CNS of DFP-treated monkeys. Part 2. Diencephalic and medial telencephalic structures.

The distribution and morphological characteristics of neurons containing acetylcholinesterase (AChE, EC 3.1.1.7.) in diencephalic and medial telencephalic structures of the rhesus monkey (Macaca mulatta) were studied by means of a pharmaco-histochemical method that involves staining for AChE (Karnovsky-Roots' procedure) at various times after the administration of di-isopropylfluorophosphate (DFP). At medial telencephalic levels, numerous, mostly multipolar, AChE-containing neurons of medium to large size are present in the bed nucleus of the anterior commissure, in the ascending division of the nucleus of the diagonal band of Broca, and in the so-called "substantia innominata". This last structure is composed of medial and lateral AChE cell groups that extend caudad, beneath the lenticular nucleus, for a considerable distance. The AChE neurons lying within the substantia innominata correspond, at least in part, to the basal nucleus of Meynert. Most neurons of the olfactory tubercle are devoid of AChE but lie within a lightly-stained AChE background. In addition, clusters of amorphous and highly reactive AChE material are found within the islands of Cajella and along the ventromedial edge of the olfactory tubercle. At the level of the thalamus, the strongest AChE staining is seen in the periokarya of the anterior dorsal nucleus and of most nuclei located within the fibrous or lamellar thalamic structures--i.e., the reticular nucleus, the intralaminar nuclei, and the midline nuclei except nuclei parataenialis and reuniens. In most of these nuclei the neuronal somata are of medium size and stain moderately for AChE. Their proximal processes are either lightly stained or devoid of AChE. At the level of the hypothalamus of the monkey, intense AChE staining can be seen within the neuronal somata of the supraoptic and paraventrivular nuclei. In the paraventricular necleus, the AChE-positive perikarya are of medium size and have numerous AChE-containing processes. Moderately reactive AChE neurons of smaller size with unstained processes are also present in the paraventricular nucleus. Most perikarya of the main rostral portion of the supraoptic nucleus are moderately stained for AChE, are closely packed, and their processes are difficult to discern. The main cellular aggregate of the supraoptic nucleus extends caudad and is composed of a large group of moderately to intensely stained neurons lying along the optic tract and which constitute the caudal, or infundibular, portion of the supraoptic nucleus. Other moderately to intensely stained AChE neurons were found in the lateral and perifornical areas and most particularly in the dorsal hypothalamic area. These neurons are of medium size and mostly multipolar. Moderately stained AChE neurons were also observed in the supramammillary nucleus, as well as those of the acruate nucleus, however, are only weakly reactive. The median eminence and most neurons of the ventromedial nucleus of the monkey hypothalamus are virtually devoid of AChE...

Acetylcholinesterase↗
PubMed1977

Morphological characteristics of the acetylcholinesterase-containing neurons in the CNS of DFP-treated monkeys.

The distribution of acetylcholinesterase (AChE, EC3.1.1.7) within extrapyramidal and related structures was studied in 4 monkeys following the i.m. administration of bis-(1-methylethyl) phosphorofluoridate (di-isopropylfluorophosphate: DFP). In 1 animal, sacrificed 4 hr after the injection of 0.43 mg/kg C, AChE is virtually absent in all structures. In the other 3 animals, which received 0.20 mg/kg DFP 10, 12 and 18 hr prior to sacrifice, AChE activity is greatly reduced in the neuropil of those structures which normally show intense AChE activity in pharmacologically unmanipulated monkeys. As a consequence of the lower background AChE activity in the latter 3 DFP-treated monkeys, the perikarya and processes of several groups of neurons can be readily identified. The perikarya and processes of two types of neurons of the neostriatum, representing a small percentage of all neurons in this structure, are intensely stained. They apparently correspond to the chromatic giant aspiny neurons and the achromatic medium-size "spidery aspiny" neurons. Most perikarya and processes of the neurons of the medial and lateral divisions of the pallidum, as well as the morphologically similar neurons of the pars reticulata of the substantia nigra, display light to moderate AChE activity. The pars compacta of the substantia nigra contains a small number of intensely stained elongated and triangular neurons and numerous moderately stained ovoid neurons whose processes are very lightly reactive. The cell bodies of the neurons of the subthalamic nucleus and associated groups of neurons (nucleus ansae peduncularis) are moderately stained whereas the perikarya and processes of the subnucleus compactus of the pedunculopontine tegmental nucleus are intensely and moderately stained, respectively. Numerous large and multipolar neurons associated with the lenticular nucleus (intralamellar groups) or the pallidum (peripallidal groups) including the nucleus ansae lenticularis have somata and processes which show an intense AChE activity. Certain of the latter groups of neurons, partially interspersed with the neurons of the substantia innominata, correspond in part to the nucleus basalis of Meynert. The present data are compatible with the idea that the large AChE neurons of the neostriatum may be the source of the acetylcholinesterasic striatopallidal and strionigral fibers. The similarity between the neurons of the pallidum and those of the pars reticulata of the substantia nigra suggests that the latter structure may represent a caudal extension of pallidal tissue. Therefore, the nigrothalamic projection, which has been claimed to originate in the pars reticulata of the substantia nigra, would correspond to pallidothalamic projections.

Acetylcholinesterase↗
PubMed1976

Organization and morphologies of acetylcholinesterase-containing neurons in the thalamus and hypothalamus of the rat.

The distribution and morphologies of neurons containing acetyl cholinesterase (AChE, EC 3.1.1.7) in the thalamus and hypothalamus of the rat were studied by means of a pharmaco-histochemical technique involving staining for AChE (Karnovsky-Roots' procedure) at various times after administration of bis-(u-methylethyl)phosphorofluoridate. This method enables visualization of individual AChE-containing neuronal somata and their processes to a degree not possible with other protocols for the enyzme. The strongest AChE activity occurring at the level of the thalamus is found within the small, round to oval, somata of nucleus anterior dorsalis. Most of the intralaminar nuclei, as well as nucleus reticularis, are composed of medium-sized multipolar neurons displaying moderate to strong AChE activity. Moderately stained AChE neurons are also found in pars ventralis of nucleus geniculatus lateralis and in pars lateralis of nucleus habenularis. Most of the neurons of the lateral and posterior thalamic territories, however, are nearly devoid of AChE. At the level of the hypothalamus, the neurons of nuclei supraoptics and paraventricularis show strong AChE activity. The AChE neurons of nucleus supraopticus are surrounded by numerous AChE-containing processes of some large lateral preoptic area neurons that stain intensely for the enzyme. Numerous intensely stained AChE perikarya occur in the lateral, dorsal, and supra-mammillary hypothalmic areas. These neurons often possess several AChE-containing processes. Nuclei arcuatus and ventomedialis consist mainly of neurons displaying a weak to moderate intensity of AChE staining. At the level of the mamillary bodies most neurons show moderate AChE activity except the neuronal somata of nucleus mammillaris lateralis which stain very strongly for the enzyme.

Acetylcholinesterase↗
PubMed1976

Postnatal development of acetylcholinesterase in the caudate-putamen nucleus and substantia nigra of rats.

The postnatal development of acetylcholinesterase (AChE, EC 3.1.1.7) and NADH-diaphorase was examined in the caudate-putamen nucleus and substantia nigra of rats ranging from 3 to 90 days in age. From 3 to 15 days post partum islands of AChE and NADH-diaphorase activity were observed in the caudate-putamen nucleus. Individual neuronal somata could also be seen in AChE-stained sections up to 15 days. At later ages neuropil staining became increasingly dense, and this presumably accounted for the infrequent visualization of cell bodies in the brains of older animals. During development AChE appeared in the caudate-putamen nucleus in a lateral to medial topographic order; analogously, enzyme staining in the neostriatum reappeared in the same lateral to medial topographic order in adult rats following irreversible AChE inhibition by intramuscularly injected bis-(1-methylethyl)phosphorofluoridate (di-isopropylfluorophosphate: DFP). Furthermore, DFP treatment in mature animals revealed the presence of AChE in striatal neurons having morphologies similar to those observed in newborn rats. A similar time-course of postnatal AChE development was observed in the substantia nigra. In both the pars compacta and pars reticulata individual cell bodies, which were visible at early ages (3-10 days), became increasingly obscured at later times after birth by extra-somata staining. Between the 6th and 15th postnatal days AChE-containing fibers were seen projecting apparently from pars compacta into pars reticulata. Comparison of the present results with histochemical data of other investigators on the postnatal development of monoamines indicated the likelihood of cholinergicmonoaminergic interactions in the neostriatum and substantia nigra.

Acetylcholinesterase↗
PubMed1976

Fast fixation of brain in situ by high intensity microwave irradiation: application to neurochemical studies.

The levels of acetylcholine and choline were measured in various brain regions of the rat after fixation by microwave irradiation of the head and after decapitation and subsequent freezing in liquid nitrogen. Levels of acetylcholine were increased by approximately 50% after microwave irradiation, while choline levels were reduced. These biochemical findings were correlated with virtually complex loss of acetylcholinesterase and NADH-diaphorase activity after 1 s exposure to microwave irradiation at a level of 5 kW.

Acetylcholine↗
PubMed1975

Acetylcholinesterase neurons in dopamine-containing regions of the brain.

A pharmaco-histochemical regimen was used to examine the morphology and internal organization of acetylcholinesterase (AChE, EC 3.1.1.7) neurons in brain areas--the caudate-putamen nucleus, nucleus accumbens, olfactory tubercule, and subtantia nigra--monoaminergically characterized in terms of their dopamine content. Intense, homogenous staining is produced in these neural regions by other histochemical protocols for AChE; individual AChE-containing neurons cannot be observed reliably or consistently. With the present technique, based on the differential regeneration of AChE in the separate subcellular compartments of the neuron (i.e., axon, dendrite, soma) after intramuscular injection of bis-(1-methylethyl)-phosphorofluoridate (di-isopropylfluorophosphate: DFP), it was shown that AChE was associated with neurons whose cell bodies lay within the brain areas studied. Although the significance of dopaminergic-cholinergic relationships in the caudate-putamen complex, nucleus accumbens, and olfactory tubercule could not be established on the basis of these new histochemical data, arguments were presented indicating that dopamine neurons in the zona compacta of the substantia nigra also contained AChE.

Acetylcholinesterase↗
PubMed1975

Degenerative processes after punctate intracerebral administration of 6-hydroxydopamine.

Various doses of the neurotoxin 6-hydroxydopamine (6-OHDA) were infused into the substantia nigra-ventromedial tegmental area, caudateputamen nucleus, and red nucleus. A maximum of four successively occurring zones of neuropathology could by detected at all injection sites: (1) A zone of complete absence of neural, glial, and vascular elements due to tissue displacement by the cannula, (2) an area of glial cells, developing over time, which surrounded the cannula tract, (3) a region exhibiting virtually complete loss of neuronal elements, and (4) a zone of selective neuropathological reaction or cellular loss in which some neurons were affected and others were not. All investigators who have histochemically and/or histologically evaluated the effects of intracerebrally administered 6-OHDA agree on the existence and genesis, some non-selective process, of the first three zones. Although some scientists maintain that the fourth zone is where 6-OHDA operates selectively, data are presented in this report that other, well-established processes can account for neuropathology beyond zone 3. Prominent among these are retrograde and anterograde degeneration, ischemia as a function of interruption of blood supply, and nonselective traumatization. In addition, the topography of the injected site (e.g., morphology of affected neurons, degree of myelination) was found to be as important a determinant of the locus of tissue damage as the presumed selectivity of 6-OHDA's action. Furthermore, monoamine oxidase inhibition by nialamide did not appear to increase the neurotoxicity of 6-OHDA. Similarly, 1-(2,5-dihydroxy-4-methylphenyl)-2-aminopropane was not a more potent cytotoxin than 6-OHDA even though this new neurotoxin has a propane side chain which renders it immune to monoamine oxidase. These observations, taken together, suggest that considerable cautioon should be exercised in interpreting data from experiments in which 6-OHDA, or related neurotoxins, are used to uncover catecholaminergic mechanisms of behavior and other functional processes.

Acetylcholinesterase↗
PubMed1975

Catecholamine correlates of isolation-induced aggression in mice.

Drugs differentially affecting catecholaminergic neurotransmission mechanisms were injected into isolated mice to assess effects on aggression. L-DOPA in combination with a peripheral decarboxylase inhibitor produced a dose-dependent decrease in the number of fights and average fight durations accompanied by an increase in attack latencies. Central dopamine levels were increased whilst brain noradrenaline and 5-hydroxytryptamine were reduced. Virtually identical effects on aggression were observed after apomorphine. Pimozide decreased fighting, but neither attack latencies nor average fight durations were effected. All doses of disulfiram virtually abolished all components of aggressive responses. The effect of D-amphetamine on number of fights was biphasic; lower doses potentiated aggression, but higher doses reduced fighting accompanied by increased attack latencies and reduced average fight durations. We conclude that catecholamines may be intimately involved in mediating certain components of aggressive responses but that balance relationships among various putative neurotransmitters may be a more meaningful correlate of this behavior.

Aggression↗
PubMed1975

Acetylcholinesterase-containing neurons in the neostriatum and substantia nigra revealed after punctate intracerebral injection of di-isopropylfluorophosphate.

Infusion of 1 mul arachis oil containing 1.5 mug bis-(1 -methylethyl)phosphorofluoridate (di-isopropylfluorophosphate: DFP) into the caudate--putamen nucleus and substantia nigra of rats produced a considerable reduction of histochemical staining for acetylcholinesterase (AChE) in these two brain regions 30--120 min after injection. Thereafter, regeneration of AChE occurred within the zone of DFP effect. These new stores of AChE were associated with discrete neuronal perikarya and their processes. Intracerebral DFP administration had little or no histochemically detectable effect on NADH-diaphorase. Thionin staining was similarly unaffected. The results with punctate intracerebral application of DFP were replicated by intramuscular injection of 1.5 mg/kg DFP. Although the significance of dopaminergic--cholinergic interactions in the neostriatum could not be elucidated on the basis of these histochemical data, the thesis was advanced that dopamine neurons in the pars compacta of the substantia nigra also contained AChE, possibly to inactivate acetylcholine released from cholinergic fibers afferent to this neural structure.

Acetylcholinesterase↗