bluuebunny/crossref_metadata_2025 huggingface dataset:
Ergot mesylates for alzheimer's disease: A year‐long double‐blind trial of 3 mg vs 12 mg daily
Authors: Jenike Michael A. , Albert Marilyn , Baer Lee , Gunther Jeanette , Corvino Christine
Published: January 2005

Of 25 patients who entered a year‐long double‐blind comparison study of high (12 mg/day) versus low (3 mg/day) dosages of ergot mesylates (Hydergine), 17 completed the full year of study and no patients suffered problematic side‐effects. On a number of complex tests of memory function, there was no difference between the patients receiving low‐dose versus high‐dose Hydergine. There were also no significant between‐group differences in recognition memory, incidental memory, naming ability, figure drawing, mood or other psychiatric symptoms. These data confirm that Hydergine is safe and that trials in a low dosage range may suffice.
Idiopathic basal ganglia calcification presenting as hypomania
Authors: Wylie Kevan R. , Harris Stephen J.
Published: January 2005

A sixty‐four‐year‐old lady manifested a hypomanic psychosis and later developed features of a subcortical dementia and movement disorders of Parkinsonism and chorea. Computerized tomography revealed bilateral basal ganglia calcification. No evidence of parathyroid disorder or any other cause for the calcification was present. There has been only one previously reported case of organic mood disorder of a manic type presentation of idiopathic basal ganglia calcification (IBGC). The oldest reported age of onset of IBGC presenting with psychosis is 53 years and with dementia is 68 years.
Acetyl‐L‐Carnitine in dementia
Authors: Livingston G. A. , Sax K. B. , McClenahan Z. , Blumenthal E. , Foley K. , Willison J. , Mann A. H. , James I. M.
Published: January 2005

This study was designed to test the benefit of acetyl‐l‐carnitine in patients with dementia. Seventy‐one patients of 65 years and over, living in their own homes or in residential care, took part in a 24‐week randomized, double‐blind, placebo‐controlled, parallel‐group clinical trial. The outcome was measured by comparing psychometric tests at 24 weeks to baseline measures. The active treatment group improved in mean scores in seven out of eight psychometric in one test. recognition memory (P>0.01). Linear discriminant function analysis indicated that active and placebo therapy could be distinguished according to the pattern of responses to the eight psychological test (p>0.01). In this small trial, acetyl‐l‐carnitine was shown to be non‐toxic and possibly beneficial. Further large‐scale trials are needed over long periods of time.
An audit of the use of antipsychotics in a geriatric psychiatry continuing care unit in Scotland
Authors: Connelly Pete R. J.
Published: January 2005

Behaviour problems, dependency levels and use of antipsychotic medication were assessed, using an audit approach, in 104 patients in a geriatric psychiatry continuing care unit. High levels of dependency and behaviour disturbance were found. 37.5% of the population were receiving regular antipsychotic medication. The severity of a cluster of four symptoms (diurnal restlessness, agitation, irritability and active aggression) tended to discriminate this group from those on no antipsychotics, though frequency of problems and total number of problems were also higher in the group on regular antipsychotics. Antidepressants were rarely used, though conversely there was only one case of ‘missed’ depression. Changes following the audit are described and recommendations for improved monitoring of medication use are made.
Quantal components of the synaptic potential induced in hippocampal neurons by activation of granule cells, and the effect of 2‐amino‐4‐phosphonobutyric acid
Authors: Yamamoto Chosaburo , Higashima Masato , Sawada Satsuki , Kamiya Haruyuki
Published: January 2005

The probabilistic nature of excitatory postsynaptic potentials (EPSPs) induced monosynaptically in CA3 neurons by impulses of granule cells was studied in thin transverse sections of the guinea pig hippocampus. More than 600 EPSPs were recorded under several conditions, their amplitudes were measured, and histograms representing the EPSP amplitude distribution were constructed. Quantal parameters were estimated by the method of maximum likelihood. Of 9 neurons examined in the control solution, one neuron showed an exceptionally large number of transmission failures. The amplitude distribution of EPSPs recorded from this neuron could be described by Pascal statistics, but not by binomial or Poisson statistics. The EPSP amplitude distribution from the other neurons could be described by either binomial, Poisson, or Pascal predictions with a minor preference for the last statistic. When an apparently homogeneous group of data was divided into two subgroups and parameters were estimated separately, inconsistent values were obtained in some neurons with no failures. 2‐Amino‐4‐phosphonobutyric acid (APB) suppressed the EPSPs reversibly at relatively low concentrations. Theoretical curves calculated according to the Pascal statistics fit quite well to the entire amplitude distribution of EPSPs recorded under the action of APB. The suppression of EPSPs by APB was accompanied by a marked decrease in mean quantal content (m) with no significant reduction in mean quantal amplitude (q). A quantum induced an increase in membrane conductance of about 150 pS. These results suggest that the release probability of the mossy fiber terminal fluctuates temporally according to a gamma distribution, and that APB reduces the liberation of the transmitter from mossy fiber terminals, thereby suppressing transmission between mossy fibers and CA3 neurons.
The effect of acute alcohol intoxication on psychometric testing and 5‐HT‐induced platelet aggregation in normal subjects: Modulatory role of evening primrose oil
Authors: Corbett R. , Meagher J. B. A. , Leonard B. E.
Published: January 2005

Groups of university students were exposed acutely to alcohol (100 ml vodka) and their performance in the Bexley Maudsley Automated Psychological Screening Tests (BMAPS) was assessed. Blood samples were also taken to assess platelet aggregation to 5‐HT challenge. After 1 week's administration of evening primrose oil (EPO) or placebo under double‐blind conditions the students were re‐assessed. No mean difference was found in the psycho‐metric testing of any of the groups either before or after the administration of EPO. However 5‐HT‐induced platelet aggregation was significantly potentiated in those groups exposed to alcohol, and was further increased in the group receiving EPO. These results suggest that platelet aggregation in response to 5‐HT is more sensitive than psychometric tests commonly used to assess alcoholism in detecting changes due to acute alcohol intoxication.
Adverse lithium‐neuroleptic interactions—are there permanent effects?
Authors: Schou Mogens
Published: January 2005

An interaction between lithium and neuroleptics may occur, at least when the latter are given in high dosage: however, the four cases described by Cohen and Cohen, although the first reported, can hardly be considered representative. Permanent brain damage is not a distinctive feature of a lithium‐neuroleptic interaction.
Some pharmacological aspects relating to the issue of possible neurotoxic interactions during combined lithium‐neuroleptic therapy
Authors: Waddington John L.
Published: January 2005

The debate on the issue of whether serious neurotoxic reactions are more likely or more problematic during combined lithium‐neuroleptic therapy, in comparison with either agent given alone, has not yet been satisfactorily resolved. Clinical pharmacokinetic studies do not indicate any profound effects of either drug on the plasma levels, distribution, and clearance of the other when given concurrently. At the preclinical pharmacodynamic level, a variety of fundamental cellular processes have been studied both in vitro and in vivo, but these either fail to indicate any basis for toxic synergism or else demonstrate interactions only at very high concentrations of questionable clinical relevance. In animal behavioural studies, there is no convincing evidence that such neurotoxic reactions occur during combined lithium‐neuroleptic administration. However these pharmacological studies must be interpreted conservatively. As such approaches also fail to model or explain the phenomena of tardive dyskinesia and neuroleptic malignant syndrome, negative findings cannot be regarded as conclusive.
Neoplasia and the neuroleptic malignant syndrome
Authors: Wooduff P. W. R. , Palazidou E. , Cranston I. , Toone B. K. , Summers B. , Eddleston A. L. W. F.
Published: January 2005

The association of neuroleptic malignant syndrome with neoplasia has not been previously reported. We report the case of a 64‐year‐old female patient who developed the classical picture of neuroleptic malignant syndrome in relation to a uterine leiomyosarcoma. This raises the question as to whether a biological predisposition exists in patients who develop neuroleptic malignant syndrome.
Moclobemide and fluvoxamine co‐administration: A prospective study in healty volunteers to investigate the potential development of the ‘serotonin syndrome’
Authors: Wallnöfer A. , Guentert T. W. , Eckernäs S. A. , Dingemanse J.
Published: January 2005

The combination of serotonin re‐uptake inhibitors and classical inhibitors of monoamine oxidase (MAO) has been associated with the severe adverse effects of the so‐called ‘serotonin syndrome’. In the present study the combined administration of moclobemide, a novel, selective and reversible inhibitor of MAO‐A and fluvoxamine, a selective serotonin re‐uptake inhibitor, was studied in 25 healthy male volunteers. Ascending doses of moclobemide or placebo were added to a steady state dosing regimen of fluvoxamine.

The highest incidence of adverse events occurred in the run‐in phase. Three subjects were withdrawn when treated with fluvoxamine alone. In the 13 volunteers receiving the active combination tiredness, dizziness and headache were more frequently noted than in the nine controls receiving fluvoxamine and placebo. The types of adverse events observed before and after the addition of moclobemide to fluvoxamine were very similar. Fluvoxamine plasma concentrations remained unchanged over the period of moclobemide co‐administration. Plasma concentrations of moclobemide were slightly higher than those observed in previous studies.

In conclusion, the combined administration of fluvoxamine and moclobemide did not precipitate symptoms of the ‘serotonin syndrome’. This is of particular relevance for the therapeutic practice if switching of the antidepressant medication is necessary.
Correlation between the sites labelled by [3H]‐8 hydroxy‐2‐(di‐N‐propylamino)tetralin and [3H]‐imipramine in human platelets
Authors: Marazziti Donatella , Rossi Alessandra , Giannaccini Gino , Martini Claudia , Castrogiovanni Silvia , Micali Maria Grazia , Lucacchini Antonio , Cassano Giovanni Battista
Published: January 2005

The authors investigated the possible correlations between the binding parameters, maximum binding capacity (Bmax) and dissociation constant (Kd), of [3H]‐8 hydroxy‐2‐(di‐N‐propylamino) tetralin and [3H]‐imipramine in platelets of 13 healthy subjects. The in vitro pharmacological characterization was also carried out for a further comparison.

The results, showing that the Bmax values were significantly and positively correlated, together with the findings of the displacement studies, suggest that in human platelets, [3H]‐8 hydroxy‐2‐(di‐N‐propylamino)tetralin and [3H]‐imipramine bind to the same protein.
Localization and response of the 14‐3‐2 brain protein
Authors: Haglid K. G. , Hydén H. , Lange P. W.
Published: January 2005

The 14‐3‐2 acidic protein specific for nerve tissue has been localized to bands 4 and 5 counted from the anodal front band in a polyacrylamide‐gel eletrophoretic pattern. The material consisted of cut‐out layers of pyramidal nerve cells of the CA3 hippocampal region of the rat. Extracted protein samples were subjected to immunoprecipitation, Coons' double‐layer immunofluorescence, microcompletment fixation, and a localization experiment using microdensitometry on a 400 μΦ gel electrophoresis pattern with a without extra added 14‐3‐2 protein. The protein fractions 4 and 5, now shown to contain 14‐3‐2 protein, have recently been found to incorporate increased precursors at training as compared to controls.
Vinblastine: Influence on nerve conduction and synaptic transmission
Authors: Felder M.
Published: January 2005

Vinblastine injected into the eyes of pigeons had a detrimental effect on the amplitude of the postsynaptic evoked potential in the optic tectum; impulse conduction of the optic nerve was not influenced. The depression of the postsynaptic evoked potential was dependent on the dosage. Only 20 and 100 μg vinblastine had an influence; no influence was observed with 10 μg vinblastine. The reversible depression was seen from the third day after injection to between the 21st and the 28th day after injection, and in that period it remained constant. The latency of the response was not influenced by vinblastine.
Regional transport of phenylalanine across the blood‐brain barrier
Authors: Pollay Michael
Published: January 2005

In adult rats, using the single‐pass brain uptake technique with a tritiated water standard, L‐phenylalanine was shown to enter brain across the blood‐brain barrier (BBB) by both a saturable and diffusionary process. A kinetic analysis of the data revealed Michaelis constant (Ka) of 0.42 mM and V max of 35 nmoles g−1 min−1 The saturable component of L‐phenylalanine transport was adversely affected by dinitrophenol or low sodium concentration in the intracarotid injection solution. Intravascular ouabain did not affect transport and only partial inhibition was observed with 1.5 mM L‐leucine. It appears that there is no regional difference in the capacity of the BBB to more L‐phenylalanine from blood to brain. This process is directly or indirectly coupled to sodium movement and is partially dependent on cellular energy.
Behavioral effects and binding affinities of two stereoisomeric psychotomimetic glycolates
Authors: Lowy Karl , Abood Leo G. , Raines Holly
Published: January 2005

A comparison was made of the behavioral effects in cats of the dextro and levo isomers of 3‐quinuclidinyl benzilate (QB), using a special computer‐controlled program. Such psychophysical parameters as rate of response and tendency to use the left or right paw for lever pressing were used primarily to evaluate drug efficacy. The drug did not alter auditory threshold or the percentage of errors in level pressing. The l‐isomer was found to be at least 100 times as potent as the d‐isomer, the effects of both being qualitatively similar. After a single dose of 5μ/Kg of 1‐QB, the cat' performance did not return to normal until 5–7 days late. Pretreatment of the cats with a dose of 2 mg/Kg of atropine, an antimuscarinic agent, did not prevent the behavioral effects of 1‐QB. The binding affinity of the two isomers for synaptic membranes and phosphatidyl serine was identical.
A vestibulothalamic pathway: Electrophysiological demonstration in the cat by localized cooling
Authors: Sans Alain , Raymond Jacqueline , Marty Robert
Published: January 2005

Localized cooling was used in the search for vestibulothalamic pathways and a study was made of its effect on the activity of the thalamic neurons brought into action by stimulation of the vestibular nerve. Two cell populations were identified by their distinctive latencies in the ventral part of the posterior thalamus. Short latency responses were transmitted monosynaptically by means of a direct controlateral pathway whose course was identified. For long latency responses, the hypothesis of a polysynaptic path seems probable.
Mesencephalic lesions resulting in normophagia, reduced weight and altered metabolism
Authors: Bellinger L. L. , Bernardis L. L. , Goldman J. K.
Published: January 2005

The effects of bilateral lesions of the ventral noradrenergic bundle (VNA) were studied in male rats. In contrast to data reported by others, hyperphagia and obesity were not observed following VNA lesions. Indeed, except for a depression during the first three postoperative days, food intake (FI) of the VNA lesioned animals (VNAL) was normal. Interestingly, the body weight (BW) of the VNAL was significantly reduced compared to the controls, and a pair feeding study indicated that this depression of BW was not due to their FI. Computation of FI per metabolic size showed that the VNAL actually had a significantly increased FI compared to the controls. After a two day fast the VNAL lost more metabolic size than controls and upon refeeding they defended their pre‐fast BW. The VNAL rats showed normal body composition and circulating glucose, insulin and prolactin. They had reduced free fatty acids, triglycerides, growth hormone and body length. The data suggest that the mesencephalon influences BW set point, some metabolites and possibly overall metabolism.
Pattern of labeling of poly (A)‐associated RNA in the CA3 region of rat hippocampus during training
Authors: Cupello Aroldo , Hydén Holger
Published: January 2005

Newly synthesized poly (A)‐associated mRNA was analysed in the hippocampal CA3 pyramidal nerve cells in rats subjected to training to reverse handedness.

The nerve cells of trained animals showed a smaller percentage of poly (A)‐associated mRNA than did the active controls. However, a specific fraction of this poly (A) hippocampal RANA with a SE value of around 25 was reproducibly stimulated. This qualitative nerve cell mRNA change is discussed in relation to similar changes in the protein pattern as a function of training.
Excitability and functional organization of cutaneous tactile units of the bullfrog (R. catesbeiana)
Authors: Holloway James A. , Ramsundar C. F. , Wright L. E.
Published: January 2005

Frog skin touch receptors are discrete structures which appear as dome‐shaped translucent elevations of the epidermis. These domes are particularly responsive to direct touch. Tactile stimulation adjacent skin never caused impulse activity, except when the skin distortion disturbed the domes. On stimulation at threshold intensity, the response of all units studied always consisted of a single impulse whether the stimulus energy was electrical or mechanical. While most tactile units discharged one impulse upon application of mechanical stimulation, a few also discharged one impulse upon stimulus release (on‐off response). No after discharge was seen at stimulus strengths of three or four times threshold or after repetitive stimulation at 1,000 pps. The range of distribution of active domes/receptive field was 1–14. Generally the most sensitive domes appeared to be in or near center field.

Twice as many of the tactile units responded more readily to cold than to warmth. The impulse frequency of units responding to thermal stimulation ranged from 3–11/Sec. The conduction velocity of tactile units measured was within a range of 9–25m/sec, with a mean of 12 m/sec. The results suggest the following: (1) the existence of discrete structures which respond to tactile stimuli; a phylogenetic relationship might be postulated; (2) cold/touch receptors which appear to be present in greater quantity in the frog's skin than are warm/touch receptors, (3) touch units which should be considered primarily as mechanoreceptros with a possible secondary function as thermoreceptors.
Responses of single units in the cat cochlear nucleus to sinusoidal amplitude modulation of tones and noise: Linearity and relation to speech perception
Authors: Hirsch Henry R. , Gibson Mary Morton
Published: January 2005

Responses to the sinusoidal modulation envelopes of amplitude‐modulated tone and noise carriers were recorded from single units in the cochlear nucleus of the cat. The unit discharges were synchronized to the peaks of the modulation envelope. Population‐averaged firing rates were independent of the modulation index of the stimulus. Temporal firing patterns, as represented by the shapes and magnitudes of modulation‐cycle histograms, were strongly dependent on stimulus intensity and modulation index. Nonlinear nonsinusoidal responses to sinusoidal modulation envelopes were observed, but only at very high values of sound intensity. These and other results are discussed in the context of psychological studies concerning the perception of speech information.
Brain colchicine‐binding protein (tubulin) during postnatal development in the rat
Authors: Gonzales Linda W. , Geel Stanley E.
Published: January 2005

A time‐decay colchicine‐binding assay was used under optimal conditions for measuring tubulin concentration in the cerebral cortex and cerebellum during postnatal development. In both brain areas soluble tubulin concentration (pmoles colchicine bound/mg tissue) declined by about 35% between 4 and 12 days of age after which the decrease was more gradual up to adulthood. Colchicine‐binding protein concentration of particulate fractions, on the other hand, increased between 4 and 12 days of age followed by relatively little change. The concentration of tubulin the soluble and particulate fractions of the cerebral cortex was 45% and 75% greater, respectively, than corresponding fractions of the cerebellum. The expression of tubulin on the basis of DNA, revealed marked regional differences which can be considered a reflection of differences in the relative extent of morphological differentiation in these areas during the postnatal period. Tubulin in both soluble and particulate fractions exhibited a marked increase in lability for colchicine binding from approximately 12 days of age. The half‐life for loss of colchicine‐binding activity was 2.5‐fold greater in particulate colchicine‐binding reaction provides additional support for the hypothesis that it represents a functionally significant association of tubulin with membranous components.
Stereospecific opiate binding in human erythrocyte membranes and changes in heroin addicts
Authors: Abood Leo G. , Atkinson Holly G. , Macneil Mary
Published: January 2005

Stereospecific opiate binding has been demonstrated in human erythrocyte membranes, having a Kd of 9 · 10–9 M. In most respects the binding characteristics resemble those of snyaptic membranes. These included the correlation of binding affinity and pharmacological potency of opiates; competition by naloxone; inhibition by Ca2+ and Na+; and sensitivity to phospholipases and tryspin. A comparison of stereospecific opiate binding in control human subjects and heroin addicts revealed a 43% increase in the addict group.
Effects of local illumination of the hypothalamus on spontaneous and flash‐induced multiunit activity recorded from the gonadotropic hypothalamic areas in quail
Authors: Oliver J. , Baylé J. D.
Published: January 2005

Multiple unit activity (MUA) was obtained from gonadotropic areas of the hypothalamus in quail. Pellets of radioluminous paint (RLP) were implanted unilaterally either in the nucleus tuberis or in the n. posterior medialis hypothalami. Control data were obtained from birds receiving nonluminous material (RP). Spontaneous MUA was decreased by 25% in gonadotropic areas in RLP‐treated quail. Direct permanent photostimulation of hypothalamic neuronal population was not as effective in decreasing MUA as environmental photostimulation (50%). Activation in firing rats, which was constant in nonphotostimulated intact birds in response to repetitive flash‐light stimulations, was completely suppressed after implantation of RLP.
Theoretical considerations of local neuron circuits and their triadic synaptic arrangements (TSA) in subcortical sensory nuclei
Authors: Lábos E.
Published: January 2005

Certain sequential models of the so‐called synaptic triadic arrangements (TSA) occurring in sensory nuclei are analyzed. The considerations addressed mainly to the lateral geniculate body. The model is based on the assumption that the neurons establishing these triads consist of conditionally coupled decision‐making subunits. It might be concluded that this and similar arrangements could play a role in the discrimination between stationary and moving retinal inputs and in the detection of temporal correlations in certain input channels.
Topographical distribution of acetylcholinesterase and butyrylcholinesterase in the diencephalon and mesencephalon of the garden lizard (Calotes versicolor)
Authors: Tewari H. B. , Sethi J. S.
Published: January 2005

The present report incorporates the histochemical mapping of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) among the various and fiber tracts of the diencephalons and mesencephalon of Calotes versicolor.

The various nuclei, for both enzymes, present varying degrees of staining, ranging from negative nuclei, on the one hand, to mild and intense staining on the other hand. Almost all the fiber tracts reveal intense activity in BChE preparations, while they demonstrate mild and moderate activities for AChE.

The nature of the various nuclei in relation to enzymativ patterns is discussed.
Incorporation of [3H] lysine into the brain and spinal cord of the Cebus (Cebus appella) and Rhesus (Macacca mulata) monkeys
Authors: Zanakis Michael F. , Wells Michael R. , Bernstein Jerald J.
Published: January 2005

The relative amounts of incorporation of [3H]lysine into various brain areas and segments of the spinal cord in adult Cebus and Rhesus monkeys were studied. One hour after subcutaneous injection of [3H]lysine, animals were sacrificed and the brain and spinal cord samples taken and processed for3H}lysine incorporation into protein (Lowry et al., 1951; Wells and Bernstein, 1976). Analysis revealed Marked differences in metabolism among brain areas within each species of monkey as well as across species. Cortical structures were generally higher in radioactive uptake than subcortical structures in both species. The Cebus monkey had the greatest variation among brain areas, particularly between cortical regions, whereas the Rhesus monkey did not show cortical variation in uptake. The ratio of incorporated to nonincorporated lysine in the brain and spinal cord was higher in the Rhesus than the Cebus monkey. Both species showed a rostrocaudal gradient of radioactivity following [3H]lysine incorporation into the spinal cord. Considering weight, size, and availability differences, the metabolism of [3H] lysine appears to differ by brain areas and spinal cord segments between species.
Neurochemical effects of cocaine following acute and repeated injection
Authors: Taylor Dorothy , Ho Beng T.
Published: January 2005

Following repeated injection in the rat, cocaine decreased the concentration of serotonin in the septum‐caudate and increased the metabolism of hypothalamic norepinephrine and also striatal dopamine to a lesser extent. Furthermore, cocaine significantly decreased the activity of the rate‐limiting enzyme, tryptophan hydroxylase. In a comparative study d‐amphetamine and methylphenidate were found to exert an effect opposite to cocaine in the activation of tryptophan hydroxylase. These findings indicate that cocaine may lower central serotonin function by decreasing its availability for neural transmission. This count account for the stimulation of locomotor activity observed after cocaine administration.
Pineal‐induced alterations in reproductive function and pituitary prolactin in the female rat: The effects of bilateral superior cervical ganglionectomy and nervi conarii transection
Authors: Blask David E. , Reiter Russel J. , Johnson Linda Y.
Published: January 2005

The reproductive organs of female rats subjected to blinding and anosmia were hypotrophic while pituitary prolactin stores were markedly depressed in these animals. All of the effects of dual sensory deprivation were reversed by either superior cervical ganglionectomy or nervi conarii transection. It was concluded that both of these surgical procedures were as effective as pinealectomyin reversing the pineal‐induced alterations in the reproductive physiology of the blind‐anosmic female rat.
Covalent coupling of calf brain prolidase
Authors: Hui Koon‐Sea , Weiss Benjamin , Hui Maria , Lajtha Abel
Published: January 2005

Calf brain prolidase covalently bound to CNBr‐Sepharose 4B, retained about 32% of the activity of the uncoupled enzyme. The free enzyme showed slightly greater stability than the bound preparation when stored at 20°C or at 0°C. However, in either case the free and bound enzymes were more stable at the lower temperature. Greater thermal stability was shown by the free enzyme than by the bound preparation over a temperature range of 25°C–60°C. The free and bound prolidase, with and without Mn+2, had maximal activity at pH 4.0. Although the bound enzyme showed a single maximum, the free preparation exhibited three pH maxima of 4.0, 9.0, and 66.8, in decreasing order of activity. The ions Ag+, Cu+, Hg+2, and Zn+2 were strongly inhibitory on the free enzyme, whereas inhibition of the bound enzyme, with the exception of Zn+2, was less. Unlike the coupled enzyme, a stimulatory effect was obtained on the free preparation with Co+3, Mg+2, and Mn+2. Various other compounds were studied and their effects were noted.
Sodium exchange between blood, brain, and CSF in normal and hydrocephalic cats
Authors: Hochwald G. M. , Wald A. , Marlin A. E. , Stern J. , Malhan C.
Published: January 2005

The exchange of sodium between blood, brain, and cerebrospinal fluid was studied in normal and kaolin‐induced hydrocephalic cats. The ventricles were perfused to measure fluid formation and Na+ exchange rates. 22Na was added to the perfusion fluid or injected intravenously as a tracer for Na+ movement. Na+ and 22Na were also measured in cortical gray and white matter. Na+ relative specific activities were calculated for brain, effluent fluid, and serum. With 22Na in the perfusion fluid, Na+ exchange was not different from nascent Na+ influx for both normal and hydrocephalic cats. Na+ relative specific activities of cortical gray and white matter were 10 times greater in hydrocephalic than in normal cats. This difference in Na+ relative specific activity for brain may be due to a higher diffusion constant or to a lower brain capillary permeability.

When 22Na was given intravenously, the Na+ diffusional exchange for normal cats was less than that measured when 22Na+ was in the perfusion fluid. In hydrocephalic cats, the Na+ diffusional exchange was effectively zero. Na+ relative specific activities of cortical gray and white matter were the same for normal and hydrocephalic cats. These findings suggest that the impaired Na+ diffusional exchange may be due to pathological changes in the choroid plexus.
Developmental changes of RNA, DNA, lipid, protein and glutamic acid decarboxylase of rat forebrain, anterior midbrain, posterior midbrain, and cerebellum
Authors: Gaitonde M. K. , Tannock Christine , Evans Gwyneth
Published: January 2005

The concentration of glutamic acid decarboxylase (μmoles of glutamic acid decarboxylated/hr/gm) was found higher in the anterior midbrain than in several other regions of the adult rat brain. It was the highest in the anterior colliculus.

A developmental study of the forebrain, cerebellum, anterior midbrain, and posterior midbrain showed that the four regions behaved as distinct organs as regards the deposition of structural constituents and the activity of glutamic acid decarboxylase. There was evidence of postnatal cell acquisition by the four regions. The rate of accretion of DNA, RNA, phospholipid, and protein was the highest in the cerebellum, but that of glutamic acid decarboxylase was highest in the forebrain during postnatal development. The results indicated that the average size of the cerebellar cell in the adult rat was smaller than that of the cell of the forebrain, anterior midbrain, and posterior midbrian. The phospholipid content compared to that of protein was higher in the posterior midbrain than in the other three brain regions.

The presence of fully differentiated GABAergic neurons in the cerebellum appear by the end of the first postnatal week.
Activation of brain typtophan hydroxylase by a phosphorylating system
Authors: Lysz Thomas W. , Sze Paul Y.
Published: January 2005

A significant activation of tryptophan hydroxylase (TPH) was achieved by the addition of 1 mM ATP and 10 mM MgCl2 to 100,000g supernatant prepared from mouse midbrain. The activation produced an increase of enzyme activity by 50–70% above control. Cyclic AMP was not a necessary component in the activation as initially suspected; neither was the involvement of a cyclic AMP‐dependent protein kinase detected. The enzyme activation by Mg+2‐ATP was totally retained after dialysis, thus excluding the possibility of an allosteric effect. In contrast to the activation, TPH was found to be sensitive to inactivation by acid phosphatase, a dephosphorylating enzyme. These findings are consistent with the proposal that the enzyme activation may involve a phosphorylation process. Furthermore, the activation by Mg+2‐ATP in the brain preparations was only minimally observed from neonatal mice and could be abolished from adult mice by administration of hydrocortisone. It appears that the phosphorylation process, as postulated here, may be under developmental and hormonal influences.
Cannabis sativa: Ultrastructural changes in organelles of neurons in brain septal region of monkeys
Authors: Myers William A. , Heath Robert G.
Published: January 2005

Ultrastructural studies of layer V pyramidal neurons of the septal region of rhesus monkeys exposed to smoke of active marihuana and of those exposed to intravenous delta‐9‐THC revealed low volume density and various degrees of fragmentation and disorganization of rough endo‐plasmic reticulum. In contrast, no changes were observed in these neurons of the septal region of control monkeys (unexposed monkeys and one monkey exposed to smoke of inactive marihuana). There were no significant differences in volume density of mitochondria or golgi apparatus between exposed animals and controls.
Molecular forms of cholinesterases in cerebrospinal fluid, blood plasma, and brain tissue of the beagle dog
Authors: Scarsella G. , Toschi G. , Bareggi S. R. , Giacobini E.
Published: January 2005

In the present study we have investigated the activity of AChE and BuChE in the cisternal CSF of the Beagle dog and have outlined the characteristics of the molecular forms of both enzymes. The same enzymes were also investigated in samples from blood plasma and brain tissue. It is concluded that AChE in CSF originates from the spinal cord and brain tissues as a result of some secretory process. A combined origin from both blood plasma and brain tissue appears to be probable for the BuChE of the CSF.
A regional study of electrophoretically separated proteins from the crude synaptosomal fractions of the developing rat brain
Authors: Davis Leonard G. , Brunngraber Eric G. , Routtenberg Aryeh
Published: January 2005

Albino rats of 1, 5, 9, 16, and 25 days of age were sacrificed, and six brain regions were dissected free. Crude synaptosomal preparations from each brain region and age were obtained by differential centrifugation. Protein content in these fractions from the six brain regions increased almost threefold between 1 and 25 days of age. The preparations were delipidated, solubilized, and subjected to polyacrylamide gel electrophoresis. The densitometric patterns of five samples from each age and brain region were analyzed for changes in the relative amount of stained protein bands. Of the polyacrylamide gel‐separated protein bands, 16 regional differences at specific ages and 20 developmental changes in specific brain regions were found to be statistically significant. The hippocampal region showed the greatest number of statistical changes in the protein pattern as a function of age, whereas the cerebellum showed none. The results suggest the importance of considering regional differences in studies of biochemical developmental changes.
Distribution of glutamate in layers of the rabbit hippocampal fields CA1, CA3, and the dentate area
Authors: Nitsch Cordula , Okada Yasuhiro
Published: January 2005

The distribution of L‐glutamic acid in single layers dissected from freezedried sections of the rabbit hippocampus was estimated by means of an enzymatic cycling procedure. Although the regional variation in glutamate content is less than that of other transmitter candidates, there were present significant differences in it between the projection fields of certain fiber connections. Glutamate concentration was highest in the termination areas of commissural fibers and Schaffer's collaterals.
Effects of excitatory and inhibitory amino acids on phasic respiratory neurons
Authors: Toleikis J. R. , Wang L. , Boyarsky L. L.
Published: January 2005

The responsiveness of phasically active brainstem respiratory neurons to several amino acids was investigated in cats under Dial anesthesia. Four‐barreled microelectrodes were used to extrude iontophoretically the putative neurotransmitters L‐glutamate, L‐aspartate, glycine, and gamma‐aminobutyric acid (GABA). L‐glutamate and L‐aspartate caused increased activity when applied to either inspiratory or expiratory neurons and appeared to be equal in efficacy. Likewise, GABA and glycine depressed ongoing phasic neural activity of both inspiratory and expiratory units. In this case, however, the dosage of GABA required to produce a given depression was significantly less than the required dosage of glycine. These findings support the hypothesis that L‐glutamate and/or L‐aspartate may act as excitatory neurotransmitter agents at the synapses of brainstem respiratory neurons and conversely, GABA may act as the natural inhibitory neurotransmitter.
Effects of anoxia and depolarization on the movement of carbon atoms derived from glucose into macromolecular fractions in rat brain slices
Authors: Domańska‐Janik Krystyna , Zalewska Teresa
Published: January 2005

Incorporation of U‐14 C‐glucose into macromolecules (lipid, protein and nucleic acid fractions) of rat brain cortex slices was studied in vitro under conditions of anoxia and reoxygenation. Additionally, the influence of depolarization on control and postanoxic U‐14 C‐glucose metabolism was investigated.

Potassium‐induced depolarization of the slices lowered their capacity to incorporate 14C from U‐14C glucose into proteins and nucleic acids without any changes in the labeling the lipids. Fifteen and 30 minutes of anoxia depressed the rate of 14C incorporation into each of the above macromolecules. When slices after 15 minutes of anoxia were transferred to an oxygenated medium their capacity to incorporate 14C from glucose into macromolecules was partly restored compared to the control.

Excess of potassium in the medium during the reoxygenation period inhibited restoration of the synthetic capacity of the slices except lipids, into which incorporation of 14C was even stimulated under depolarizing conditions.

The influence of anoxia and depolarization were investigated also in different classes of lipids and proteins. 14C incorporation into SDS‐extractable and residual proteins and phospholipid fraction containing phosphoinositol was closest to the control during reoxygenation which suggests the relatively highest resistance of these fractions to anoxia.
Similarities in effects of acetylcholine and dopamine on horizontal cells in the fish retina
Authors: Negishi K. , Drujan B. D.
Published: January 2005

The effect of acetylcholine (ACh) on cone‐ and rod‐connected horizontal cells (generating photopic and scotopic L‐type S‐potentials, respectively) in the fish (Eugerres plumieri) retina was compared with that of dopamine (DA), and some similarities were found in the effects. About two‐thirds of the L‐type horizontal cells examined were sensitive to a test solution containing ACh (10 mM in concentration) and BW‐anticholinesterase (BW; 1.0 mM). ACh with BW augmented a center response and attenuated a surround response as did DA (0.2 mM), although the latter effect was more pronounced and longer‐lasting. ACh with BW frequently produced oscillations of the horizontal cell membrane potential as did DA with clonidine (α‐adrenergic stimulant). Phentolamine (α‐adrenergic blocker) interrupted both the effects of DA and ACh on the center and surround responses, while hexamethonium (cholinergic antagonist) appeared to interfere selectively with the effect of ACh. Therefore, the ACh‐induced changes observed in the horizontal cell membrane potential are assumed to be mediated by the adrenergic system in the fish retina.
Effects of some amino acids on horizontal cells in the fish retina
Authors: Negishi K. , Drujan B. D.
Published: January 2005

Effects of some amino acids on horizontal cells were examined in the fish (Eugerres plumieri) retina. L‐aspartate (5 mM in concentration) and L‐glutamate (10 mM) consistently depolarized all types of horizontal cells, although the effect of L‐aspartate was more pronounced. γ‐Aminobutyric acid (GABA; 10 mM) consistently hyperpolarized the cone‐connected L‐ and C‐type horizontal cells, whereas the effect on the rod‐connected cells was slight or nonexistent. The hyperpolarizing effect of GABA on the cone‐horizontal cells was markedly diminished by picrotoxin (0.1 mM). Usually, glycine (10 mM) showed slight and variable effects. It merely depolarized some cone‐horizontal cells but weakly hyperpolarized some rod‐horizontal cells. In a few cases, however, glycine began to drastically hyperpolarize the cone‐horizontal cells in retinas that had been repeatedly treated with certain agents used. Taurine and β‐alanine (10 mM each) had negligible effects, although the former slightly depolarized and the latter merely hyperpolarized both cone‐ and rod‐horizontal cells.
Effects of cortical ablation on the neurotoxicity and receptor binding of kainic acid in striatum
Authors: Biziere Kathleen , Coyle Joseph T.
Published: January 2005

Lesions of the cerebral cortex alter striatal neuronal vulnerability to locally injected kainic acid. Whereas extensive lesions involving the frontal‐parietal‐occipital cortex are most effective, lesions limited to the frontal or to the dorsal‐lateral parietal cortex offer partial protection. The extensive cortical lesions are associated with selective, marked reductions in the presynaptic markers for glutamatergic afferents in striatum. The protective effects of decortication appear between 6 and 24 hours the lesion and are maintained up to 30 days after decortication. Whereas decortication results in only a transient reduction of specific receptor binding of [3H] kainic acid to striatal membranes, lesion of striatal intrinsic neurons with kainic acid causes a delayed but marked reduction in specific binding of the ligand. Coadministration of L‐glutamic acid (1 μmole) with kainic acid (9 nmoles) partially restores the neurotoxic action of kainic acid in the decorticate striatum; GABA, alanine, and proline (1 μmole) are ineffective with regard to restoring kainate's toxicity for striatal GABAergic neurons. These results suggest that afferent input exerts a permissive effect on the neurotoxic action of kainic acid and that neurotoxicity may involve a cooperative interaction between kainic acid at specific receptors on vulnerable neurons and synaptically released endogenous neurotransmitters, in particular L‐glutamic acid.
Some mechanisms underlying actions of ketamine on electromechanical coupling in skeletal muscle
Authors: Marwaha J.
Published: January 2005

The effects on excitation contraction coupling (ECC) of ketamine (a dissociative general anesthetic) were investigated using the sartorius muscle of the frog. Extracellular studies revealed that ketamine depressed action potential production in a concentration‐dependent manner. Ketamine decreased both the conduction velocity and the compound action potential while concomitantly increasing the threshold current. Intracellular studies showed that ketamine caused a slight non‐significant decrease in the membrane potential and also decreased the threshold potential (mechanical threshold). Ketamine (1.5 × 10−4 M and 3.0 × 10−4 M) initially potentiated and then blocked the twitch response elicited by direct muscle stimulation. Both of these effects were statistically different from control values. These findings suggest that ketamine alters action potential production in frog skeletal muscle. This property of ketamine contributes in part to the disruption of ECC observed with this drug. The results suggest that ketamine probably interferes with calcium binding, its release and/or its fluxes which may contribute to the initial potentiation and subsequent depression of twitch tension.
Partition coefficients of 2,2,6,6‐tetramethylpiperidine‐1‐oxyl (TEMPO) in erythrocyte lipids in multiple sclerosis
Authors: Berner Bret , Blanco Cesar E. , Ellison George W. , Myers Lawrence W. , Hirsch Hilde E.
Published: January 2005

Electron spin resonance (ESR) was used in a search for a possible generalized membrane defect underlying myelin instability in multiple sclerosis (MS). In contrast to most ESR studies of biological membranes, a small, nonelectrolyte spin label, TEMPO, was chosen; its partition coefficient was determined in extracted erythrocyte lipids from MS patients and normal controls. No differences were observed. The advantages and limitations of TEMPO in comparison with lipid spin labels as probes for the study of biological membranes are discussed.
Depth‐duration profile of the immobility reflex: Theoretical implications for its triggering, sustaining, and terminating mechanisms
Authors: Rakshit A. , Klemm W. R.
Published: January 2005

Immobility reflex (IR) durations of rabbits were remarkably consistent (weighted average range of 0.36–0.70 minutes/trial), under the special conditions when rabbits were “habituated” by approximately 25 preliminary trials and when termination of IR was operationally defined as the point at which any attempt, even abortive, at righting occurred. When the mean duration for each rabbit was normalized (into quartile duration points) and then rabbits were tested at these points to determine arousal threshold, each rabbit revealed a clear progressive decrease in the “depth” of IR as the duration of a given episode progressed.

Both duration and depth were decreased when body hair was removed. The hippocampal EEG revealed persistent theta activity throughout a given trial; but the specific frequency the theta increased briefly just prior to induction of IR and decreased immediately afterwards. In Short‐duration trials, theta frequency increased progressively until the IR terminated spontaneously. In long‐duration trials frequency changes oscillated.

Each of these observations in interpreted to support the theory that, during IR, reverberating neural circuits (in the brainstem reticular formation) are activated and their output inhibits spinal motor neurons.
Behavioural effects of chronic treatment with apomorphine in combination with neuroleptic drugs
Authors: Kenny Marie , Leonard B. E.
Published: January 2005

Groups of male Wistar rats were injected with either apomorphine alone twice daily for one week or with apomorphine in combination with chlorpromazine or thioridazine. The neuroleptics were adminsitered once daily so that it was possible to assess their duration of effect on the apomorphine responses. Other groups were injected with saline (controls) chlorpromazine or thioridazine.

The nature and time of onset and duration of the stereotyped response following apomorphine injection was determined twice daily. In addition, the behaviour of the rats on the hole board apparatus was also assessed after seven days of drug treatment.

Apomorphine was found to induce either a “sniffing/burrowing” or a “fighting” stereotypy. Chlorpromazine in creased the latency and reduced the duration of both types of stereotypy. In contrast thioridazine only increased the latency and reduced the duration of response in the “fighting” group. On the hole board apparatus, both neurolepties reduced the ambulation and rearing scores of the “fighting” groups alone.

It is suggested that the different types of stereotypy induced by chronic apomorphine administration, and their sensitivity to the two neuroleptics, are mediated by different types of dopamine receptors.