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To examine the consequences of nigrostriatal denervation and L-dopa treatment on the basal ganglia output system, we analyzed, by quantitative in situ hybridization, the messenger RNA coding for glutamic acid decarboxylase (Mr 67,000) (GAD67 mRNA) in pallidal cells from patients with Parkinson's disease (PD), monkeys rendered parkinsonian by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) receiving or not receiving L-dopa, and their respective control subjects. In MPTP-treated monkeys, the expression of GAD67 mRNA was increased in cells from the internal pallidum, and this effect was abolished by L-dopa treatment. There were no differences in the levels of GAD67 mRNA between patients with PD, who were all treated with L-dopa, and control subjects. These results indicate that the level of GAD67 mRNA is increased in the cells of the internal pallidum after nigrostriatal dopaminergic denervation and that this increase can be reversed by L-dopa therapy.NEUROLOGY 1996;47: 219-224

In order to examine the consequences of nigrostriatal denervation on metabolic and functional activity of the basal ganglia, we analysed the distribution of cytochrome oxidase, a metabolic marker for neuronal functional activity, throughout the different basal ganglia structures in parkinsonian syndromes. The study was performed using enzyme histochemistry and densitometric measurements in patients with Parkinson's disease and in monkeys rendered parkinsonian by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyrydine (MPTP) intoxication. In MPTP-intoxicated monkeys compared to control animals, enzyme activity was significantly increased in the subthalamic nucleus and in the output nuclei of the basal ganglia, e.g. the internal segment of the globus pallidus and the substantia nigra pars reticulata, but remained unchanged in the external segment of the globus pallidus and the striatum. L-DOPA treatment reversed the increased enzyme activity in all of the affected structures studied. In contrast, in parkinsonian patients, who had all been chronically treated with L-DOPA, no changes in enzyme activity were detected compared to control subjects. The results in MPTP-intoxicated monkeys are in agreement with the accepted model of basal ganglia organization, in which the output nuclei of the basal ganglia are considered to be overactive after nigrostriatal denervation, partly due to increased activity of excitatory afferents from the subthalamic nucleus. Since the increased enzyme activity in MPTP-intoxicated monkeys was reversed by L-DOPA therapy, the unchanged cytochrome oxidase activity observed in parkinsonian patients might result from L-DOPA treatment, combined with the chronicity of nigrostriatal denervation.

The effects of nigrostriatal denervation and L-dopa therapy on GABAergic neurons were analysed in patients with Parkinson's disease and in monkeys rendered parkinsonian by MPTP intoxication. The expression of the messenger RNA coding for the 67 kDa isoform of glutamic acid decarboxylase (GAD67 mRNA), studied by quantitative in situ hybridization, was used as an index of the GABAergic activity of the striatal neurons. A significant increase in GAD67 mRNA expression, generalized to all GABAergic neurons, was observed in MPTP-treated monkeys compared to control monkeys in the putamen and caudate nucleus (+44 and +67% respectively), but not in the ventral striatum. L-Dopa therapy significantly reduced GAD67 mRNA expression in the putamen and caudate nucleus to levels similar to those found in control monkeys. However, the return to normal of GAD67 mRNA expression was not homogeneous across all neurons since it was followed by an increase of labelling in one subpopulation of GABAergic neurons and a decrease in another. These data suggest that in MPTP-treated monkeys the degeneration of nigrostriatal dopaminergic neurons results in a generalized increase in GABAergic activity in all the GABAergic neurons of the striatum, which is partially reversed by L-dopa therapy. As the expression of GAD67 mRNA is less intense in the ventral than in the dorsal striatum, this increase in striatal GABAergic activity may be related to the severity of nigrostriatal denervation. In parkinsonian patients who had been chronically treated with L-dopa, GAD67 mRNA expression was significantly decreased in all GABAergic neurons, in the caudate nucleus (by 44%), putamen (by 43.5%) and ventral striatum (by 26%). The opposite variation of GAD67 mRNA in patients with Parkinson's disease, compared with MPTP-treated monkeys, might be explained by the combination of chronic nigrostriatal denervation and long-term L-dopa therapy.

The effect of chronic alcoholism in the neuronal nuclear area (karyometry) of the lateral entorhinal cortex at three rostro-caudal levels (rostral, intermediate and caudal) has been studied in 19 alcoholic subjects and in 15 aged-matched controls. Cases were distributed into three groups according to their age (29–44, 45–60 and 61–70 years of age). In the second group (45–60 years), the nuclear size in layers II and III of the caudal entorhinal cortex showed a very significant decrease compared to controls. The first group (29–44 years) also showed a significant reduction in size, while the third group presented the smallest differences. The presence of cirrhosis in the alcoholic group did not vary the observed results. Thus, chronic alcoholism significantly decreases the nuclear size in layers II and III of the lateral entorhinal cortex, and thus the entorhinal output to the hippocampus may be altered in alcoholism.

Article abstract-We analyzed postmortem GABAergic neurons in the basal ganglia of three patients with progressive supranuclear palsy (PSP) and four matched controls by means of glutamic acid decarboxylase (Mr 67,000 (GAD67)) mRNA in situ hybridization. In PSP, we found a 50 to 60% decrease in the number of neurons expressing GAD67 mRNA in the caudate nucleus, ventral striatum, and the external and internal pallidum. The expression of GAD67 mRNA per neuron was reduced in the caudate nucleus and putamen (-43%), the ventral striatum (-55%), and the external and internal pallidum (-59% and -68%). Our data indicate that striatal and pallidal GABAergic neurotransmission is markedly reduced in PSP and we suggest that this alteration may account for the motor and cognitive symptoms observed in PSP. Furthermore, the destruction of the basal ganglia output systems may explain the lack of responsiveness to L-dopa therapy of PSP patients.NEUROLOGY 1995;45: 127-134

We analyzed the effect of two different schedules of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment on dopaminergic systems in the striatum of cynomolgus monkeys. Acute MPTP treatment produced a marked dopamine (DA) depletion, more severe in the caudate nucleus than in the putamen. Chronic MPTP induced a more pronounced reduction in DA levels, the putamen being slightly more affected than the caudate nucleus, in accord with immunohistochemical findings that showed a higher loss of tyrosine-hydroxylase positive neurons in ventral subpopulations of the substantia nigra pars compacta. A striking increment in the quotient DOPAC+HVA/DA was also observed in chronically but not in acutely treated monkeys, especially in the putamen. In chronically treated animals there was a nearly complete loss of DA in all subdivisions of the putamen. In the caudate nucleus, a rostrocaudal gradient of DA depletion was found, with a greater decrease in DA concentration in the rostral parts, especially in the dorsolateral portions. The pattern of striatal DA loss characteristic of Parkinson's disease can be reproduced to a certain extent in MPTP-intoxicated primates.

A common phenomenon in higher plants is the alternation of two phases in their life cycle: a conspicuous diploid sporophyte that develops from the zygote and a reduced haploid gametophyte that develops from spores produced by meiosis. The gametophytic phase has been progressively reduced both in terms of duration and relative biomass along the evolutionary line (Heslop-Harrison 1979). Its reduction is at its greatest in Angiosperms, where typically, the mature male gametophyte (microgametophyte) consists of three haploid cells (the vegetative cell and the two sperm cells), and the female gametophyte (megagametophyte) of six haploid cells within a single binucleate cell. The pollen grain of flowering plants acts as a vector for the delivery of the two sperm cells (male gametes) to the megagametophyte of the ovule, accomplishing a unique feature of Angiosperms: double fertilization. Several reports deal with the physiology of the male gametophyte from its development in the anther up to fertilization (different aspects reviewed in Knox 1984a,b; Shivanna and Johri 1985; Knox et al. 1986; Dickinson 1987; Heslop-Harrison 1987; Mascarenhas 1989, 1990a,b). For many years it had been assumed that the majority of the genome in the male gametophyte was repressed with only the genes required to germinate, produce the pollen tube, and achieve fertilization being active (Brink and MacGillivray 1924; Heslop-Harrison 1979). The male gametophyte, however, now appears to be not just a simple transmission vector for the genome, but also an independent organism expressing its own genetic information (Mascarenhas 1989, 1990a,b). As such, we could expect selection to operate in the gametophytic phase resulting in a change in gene frequencies in the subsequent generation. Jones, as early as 1928, proposed that ‘in the spermatophytes fertilization is dependent upon the ability of pollen tube to grow, and discrimination between the gametes from different individuals and between different gametes from the same individuals is made before the germ cells come in contact’. Genetic differences among microgametophytes, if expressed, would result in gametophytic competition and gametophytic selection leading to nonrandom fertilization (Snow 1986a; Mulcahy and Mulcahy 1987; Schlichting et al. 1990).

Hyperactivity in the subthalamic nucleus (STN) projections to the globus pallidus medialis (GPM) has been established as a crucial feature of parkinsonism in animal models of Parkinson's disease (PD). Recent experiments blocking the STN glutamatergic output to GPM or lesioning the STN support this concept by showing a dramatic reversal of parkinsonism. We review the role of stereotaxic surgery in the past and the possible future application of subthalamotomy for PD.

We have examined the influence of chronic GM-1 treatment (20mg/kg i.m. for 16 consecutive days) on the extent of dopaminergic damage induced by acute l-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration in cynomolgus monkeys using immunohistochemical and neurochemical analysis. The total number of tyrosine hydroxylase-immunoreactive neurons was reduced in different catecholaminergic mesencephalic regions of MPTP-treated monkeys such as substantia nigra pars compacta, mainly in the ventral portion of the nucleus (39% reduction), substantia nigra pars lateralis (31%), peri- and retrorubral catecholaminergic cell group and ventral tegmental area (A8 and A10 respectively, 20% reduction). A similar degree of neuronal loss was observed in the MPTP + GM-1-treated animals, suggesting that GM-1 ganglioside does not exert a protective effect against MPTP-induced dopaminergic cell loss. Moreover, no neurochemical recovery from the striatal dopaminergic depletion induced by MPTP was found after GM-1 treatment. However, the optical density of tyrosine hydroxylase fibers and the cellular tyrosine hydroxylase content were increased in the substantia nigra pars compacta and ventral tegmental area of the MPTP-treated monkeys which received GM-1 ganglioside, compared with animals treated only with the neurotoxin. These results indicate that GM-1 does not protect against cell death but exerts a neurotrophic effect on surviving dopaminergic neurons in the midbrain of MPTP-lesioned monkeys, suggesting that GM-1 ganglioside may be potentially useful for the treatment of neurodegenerative disorders such as Parkinson's disease.

GAD mRNA was detected in human and monkey brain postmortem by in situ hybridization with an [35S]-labelled copy RNA corresponding to a 2.7-kb fragment of the coding region of human GAD mRNA. A characteristic and reproducible pattern of hybridization was obtained with the anti-sense, but not the sense probe in both monkey and human brain. Microscopic examination of tissue sections showed that only neuronal perikarya, not glial cells, were labelled. The data confirm the heterogeneity of GAD mRNA distribution reported in rodent brain and non-human primate brain.

The effect of short-term ethanol intoxication in systems implicated in memory and other cognitive functions in rats has been assessed by studying the variation in the karyometry of the neurons in the different layers of the lateral entorhinal cortex. The analysis showed that short-term ethanol consumption produced a reduction in the nuclear area of neurons in layers V and VI, and to a lesser extent, in layers II and III. These results suggest that the deep layers of the entorhinal cortex are more sensitive to ethanol intoxication, thus more likely affecting cortical and subcortical projections than the hippocampal output.

The phase that elapses from pollination to fertilization is re-examined giving special attention to pollen pistil interaction in compatible matings. Pollination induces an activation of the pistil. A number of changes take place in the different tissues of this organ that appear to support male gametophyte development and to assist fertilization. Thus pollination induces stigma secretion, the release of starch from the transmitting tissue and prolongs embryo sac viability. It appears that even those pollen grains that do not achieve fertilization have a synergistic role supporting others to do so. The pistil also has an effect on pollen tube growth. Pollen tube growth along the pistil is not continuous, accelerations and decelerations take place depending on the different tissues they traverse. The fact that pollen tube growth is heterotrophic, at the expenses of the pistil reserves, and that these reserves are not continuously produced confers the pistil with a role controlling pollen tube growth kinetics.

During the gametophytic phase there is a luxurious production of individuals. However,from all of them, only a few achieve fertilization and pass into the next generation. While many are randomly lost, others are left behind during the time that goes from pollination to fertilization.

The topographical organization of the afferent input from the periaqueductal gray matter (PAG) to the cerebral cortex has been assessed in rats by retrograde transport of the fluorescent tracers Fast blue (FB) and Diamidino yellow (DY). The olfactory, medial frontal (infralimbic, prelimbic and anterior cingulate cortices), lateral frontal (motor), parietal, temporal, occipital and insular cortices were explored by placing two fluorescent tracers into two different cortical regions. The PAG contained the largest number of labeled neurons in medial frontal cortex injections, followed by olfactory and lateral frontal cortices. Fewer retrogradely labeled cells were seen after injections in parietal, temporal occipital and insular cortices. All labeled cells were exclusively located in the medial and lateroventral divisions of the PAG (PAGm and PAGlv). The longitudinal extent of the labeling in PAGm was more extensive than in PAGlv. The labeled neurons in the medial frontal cortex group extended through most of the PAG, while in the remaining groups it was restricted to the caudal one-third of the PAG. Neurons with projections to two different cortical regions were only a small fraction of the total population of labeled cells. Our data indicate that the medial frontal cortex is the most important recipient of a direct PAG input, followed by the lateral frontal cortex. Parietal, temporal, occipital and insular cortices receive only a minor projection. It is concluded that the PAG sends direct projections over the majority of the cortical mantle. Therefore, the possibility arises that the cerebral cortex receives a direct influence from the brainstem without a thalamic relay.

Cortical injections of the fluorescent tracers Fast blue and Diamidino yellow resulted in retrogradely labeled cells in the dorsal tegmental region of the rat. Both the laterodorsal tegmental nucleus and the ventromedial portion of the dorsal tegmental nucleus presented labeled cells. Topographically, the most robust projection was directed to the medial frontal cortex, followed by the olfactory and lateral frontal (motor) cortex. Fewer labeled cells appeared after parietal, temporal or occipital cortex injections.

summary Changes in the ovular tissues of peach (Prunus persica (L.) Batsch) were studied from anthesis to fertilization or degeneration in pollinated and unpollinated flowers. During this time the ovule undergoes a continuous developmental process. At anthesis the megagametophyte is immature and is not fully developed until 12 days later. During the first three weeks following anthesis the ovule increases in length from 400 to 1200μUm, and the nucellus and integuments undergo various changes particularly in the distribution of starch and cutin. These appear to be connected with early embryo sac nutrition and protection. As the ovule matures, starch accumulates mainly in the embryo sac, integuments and at the nucellar tip. This starch disappears during early embryo sac elongation. Concomitant with starch depletion, the cutin that separated the integuments from the nucellus vanishes. Other cutin accumulates between cells in the nucellar tip, thus protecting and isolating the embryo sac. Most of these changes appear to be a fixed feature of ovule development since they were also observed in a few long lived ovules in unpollinated flowers. However, in unpollinated flowers development of most of the ovules is soon interrupted: callose accumulates af the chalaza, starch disappears and the ovules degenerate.

Blood vessels are the way for nutrients present outside the brain to gain access into the cerebral parenchyma. When neurons are diseased, for example by toxin exposure, reactive glial cells secrete local factors that induce microangiogenesis, probably as part of a spontaneous neuroprotective mechanism related to the increased metabolic demand. In Parkinson's disease (PD) and non human primate models of PD, nigral degeneration is associated with gliosis and microvascular proliferation. Interestingly, microangiogenesis also facilitates the entrance into the brain parenchyma of neurotoxins and harmful cytokine-releasing blood cells, both of which have been linked to neuronal cell death in PD. In the present review we discuss the potential implications of vascular-related phenomena with mechanisms of neuronal damage in PD.

The protective effect of GM1 ganglioside against nerve cell death induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was analyzed in monkey mesencephalon. Administration of GM1 before and during MPTP treatment improved motor performances compared with MPTP-treated animals that received saline rather than GM1. Postmortem analysis revealed that GM1 did not protect dopaminergic cell bodies from MPTP intoxication but resulted in an increased immunoreactivity of tyrosine hydroxylase in the perikarya and processes of the surviving neurons. These data suggest that GM1 may be potentially used as a palliative rather than a curative therapy in Parkinson's disease.

7 Pags., Pollen tube growth has been studied in peach and has been related to changes in the pistil structures which the pollen tube has to traverse in its way from the stigma down to the ovule. Growth of the pollen tubes along the pistil is not continuous. While pollen tubes reach the base of the style 7 days after pollination, fertilization does not take place until 12 days later. Pollen tubes stop for 5 days at the top of the obturator and they further stop for 3 days before entering the ovule. The pollen tube growth is heterotrophic; starch, present all along the pistilar tract at anthesis, vanishes as the pollen tubes pass by. Discontinuous pollen tube growth appears to be controlled by the pistil. At anthesis the pistil is not fully matured. Maturation of the pistil implies a number of secretory processes that occur in a basipetal way starting from the stigma down to the style and ending in the ovule. Some of these secretions at the stigma and the style are triggered by pollination; others appear to be a maturative stage of the pistil and are produced in a discrete way. The fact that the pollen tube depends on these secretions together with the fact that these secretions are not continuously produced confer upon the pistil a role of controlling pollen tube kinetics and point out that, for a successful fertilization, male gametophyte development and pistil maturation need to by synchronized.

The structural events accompanying the maturation of the pistil of Petunia hybrida have been studied in detail, together with the changes in the protein spectrum of the transmitting tissue that occur over this period. These events have been considered in terms of the acquisition of the self-incompatibility response, which occurs while the pistil is enclosed in the bud. Apart from several minor differences, the young pistils differ only from the mature in that their transmitting tissue cells fail to respond to pollination by undergoing characteristic ultrastructural changes. Data from electrofocusing indicates that several proteins, mobilised in the mature transmitting tissue some three hours after pollination, are absent from bud pistils. It is proposed that the pollination-stimulated release of certain polypeptides, believed to be involved in the self-incompatibility response, does not take place in young pistils. These observations are considered with reference to currently-accepted models of the operation of the self-incompatibility mechanism in Petunia.

Changes in the obturator of the peach ( Prunus persica) have been investigated and related to pollen tube growth in this region. At anthesis, the cells of the obturator are active and rich in starch reserves. Twelve days after anthesis these cells produce a secretion that stains for carbohydrates and for proteins. As the secretion is produced, starch vanishes from these cells and they degenerate and collapse as callose is accumulated. Secretion is independent of pollination as it takes place in a similar fashion both in pollinated and in unpollinated flowers. Pollen tube growth along the obturator surface depends on this secretion for, although pollen tubes reach the base of the style seven days after pollination, they cannot grow on the obturator until five days later, when the secretion is produced. This discontinuous secretion taking place at the obturator may provide a mechanism that controls the entrance of pollen tubes into the ovary in the peach.

The observation that both compatible and incompatible pollen tubes grow at identical speeds on the stigma in many plants with 'gametophytically controlled' self-incompatibility (SI) systems has, in Petunia, been extended to cover all other facets of pollen behaviour on this tissue. On entry into the stylar transmitting tissue both types of tubes accelerate, but the compatible achieve a higher terminal velocity than do the incompatible, which eventually slow and stop. Grafting experiments show that the top 1 mm of the stylar tissue can play an important rôle in determining the future development of the pollen tube. Following mixed pollinations, proportionally too many 'compatible' pollen tubes reach the ovary than would be expected from the results of 'pure' compatible and incompatible pollinations indicating that incompatible pollen in some way helps 'prime' the style for growth of compatible pollen tubes. This data is considered in terms of recent structural studies of these tissues, and related to the pollination conditions pertaining to Petunia populations in the field.

2 Pags. The definitive and complet version (6 Pags.) is available at: https://link.springer.com/book/10.1007/978-3-642-73271-3, Siphonogamy, or the fact that fertilization is mediated through a pollen tube, is emerging as a uniquely adapted system for male-female interaction (Heslop-Harrison, 1983) and for male gametophyte selection (Mulcahy, 1979). However, we still know very little on the physiological mechani sms that control such selection. A better understanding of male-female interaction from pollination to fertilization may enlighten this process. In this respect most of the work has been done regardi ng poll en germination at the stigma (Heslop-Harrison and Heslop-Harrison, 1985) or concerning pollen tube growth in the style (van Went and Willemsen, 1984). However, there is a paucity of data regarding pollen tube growth in the ovary region (Knox, 1984).

Embryo sac development has been investigated in unpollinated, cross pollinated and gibberellic acid (GA2) treated flowers of Pyrus communis L. While pollination and GA3 treatments do not alter embryo sac development, they prolong embryo sac viability. In untreated unpollinated flowers, ovules degenerate between 12 and 21 d after anthesis, while in cross pollinated and GA3 treated flowers this degeneration is postponed by about 10 d. Thus, in a cross pollinated flower this extends the period over which a successful fertilization can take place. This increased period of viability is accompanied by an elongation of the embryo sac itself. Elongation takes place two weeks prior to fertilization in cross pollinated flowers.The extension of life span of embryo sacs following pollination and treatment with gibberellic acid indicates that a stimulus induced by 'pollination' could be mediated by GA3 Whatever its mechanism of operation, the prolongation of embryo sac viability by pollination represents a selective advantage, in that the period at which the ovules are receptive to fertilization must be significantly extended., Thanks are also due to CAICYT for financial support and for the award of a scholarship to M. G.

The structural events in the stigma and transmitting tissue of Petunia hybrida pistils that accompany compatible and incompatible intraspecific pollinations have been investigated in detail, together with the changes in reserve levels that also take place at this time. Many of these phenomena may be explained in terms of 3 phases of secretion by the cells in the upper regions of the transmitting tissue. The first, independent of pollination, results in the deposition of an intercellular matrix, rich in protein and carbohydrate. The second, triggered by pollination, although independent of the compatibility of the pollen grain, involves synthesis of molecules believed to be specific to the S(incompatibility)-gene system. The third phase of secretion occurs only following a compatible mating, and involves the transfer of stylar reserves to support the growth of the pollen tubes. These observations are discussed in terms of current models of the incompatibility mechanism operating in Petunia.

Unilateral lesion of the subthalamic nucleus (STN) produces both in humans and animals a violent and continuous hemidyskinesia (hemiballism) which may interfere with normal movement (Whittier and Mettler, 1949; Carpenter et al., 1950; Dierssen and Gioino, 1961). This well established observation has traditionally been used to support the crucial role of the STN in motor control. The prevailing view for many years was that the STN exerted a powerful inhibitory influence upon the medial globus pallidus (GPM) (Whittier and Mettler, 1949; Martin, 1967). However, as it is often the case, such clinicopathological deduction upon the normal physiology of the STN was not entirely correct.

The effective pollination period was determined in kiwifruit [Actinidia deliciosa (Chev.) Liang and Fergusonl andthe factors affecting it were evaluated. The effective pollination period, measured as the capability to set fruit after hand-pollinating flowers of different ages, was 4 days; 5 days after anthesis fruit set decreased and 2 days later it was nil. Pollentube growth did not appear to he a limiting factor since pollen tubes grew quickly and reached the base of the style 2 daysafter pollination and reached the ovules 1 day later. Ovules appeared viable for the 7 days following anthesis, and visiblydegenerated within the following 3 days. Stigmatic receptivity was determined by the ability to sustain pollen germinationafter hand pollinating flowers of different ages. The duration of stigmatic receptivity closely fit the effective pollinationperiod determined through fruit set. Thus, it appears that stigma receptivity is the main factor responsible for the shorteffective pollination period, We also thank INIA for providing a fellowship to M.V.G. Financial support came from projects INIA 9123 and 8559 and CICYT AGF 92-0739.

A Sanchez-Bahillo1, V Bautista-Hernandez1, Carlos Barcia Gonzalez1, R Bañon2, A Luna2, EC Hirsch3, Maria-Trinidad Herrero11Clinical and Experimental Neuroscience, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); 2Department of Legal Medicine, Department of Human Anatomy, School of Medicine, University of Murcia, Campus de Espinardo, Murcia 30100, Spain; 3INSERM U679 Hôpital de la Salpêtrière, Boulevard de l’Hôpital, Paris, FranceAbstract: Suicidal behavior is a problem with important social repercussions. Some groups of the population show a higher risk of suicide; for example, depression, alcoholism, psychosis or drug abuse frequently precedes suicidal behavior. However, the relationship between metabolic alterations in the brain and premorbid clinical symptoms of suicide remains uncertain. The serotonergic and noradrenergic systems have frequently been, implicated in suicidal behavior and the amount of serotonin in the brain and CSF of suicide victims has been found to be low compared with normal subjects. However, there are contradictory results regarding the role of noradrenergic neurons in the mediation of suicide attempts, possibly reflecting the heterogeneity of conditions that lead to a common outcome. In the present work we focus on the subgroup of suicide victims that share a common diagnosis of major depression. Based on post-mortem studies analyzing mRNA expression by in situ hybridization, serotonergic neurons from the dorsal raphe nucleus (DRN) from depressive suicide victims are seen to over-express cytochrome oxidase mRNA. However, no corresponding changes were found in the expression of tyrosine hydroxylase (TH) mRNA in the noradrenergic neurons of the Locus Coeruleus (LC). These results suggest that, despite of the low levels of serotonin described in suicide victims, the activity of DRN neurons could increase in the suicidally depressed, probably due to the over activation of serotonin re-uptake. No alteration was found in noradrenergic neurons, suggesting that they play no crucial role in the suicidal behavior of depressive patients.Keywords: depression, suicidal behavior, dorsal raphe nucleus, noradrenergic neurons

The expression of the protooncogene bcl-2, an inhibitor of apoptosis in various cells, was examined in the adult human brain. Several experimental criteria were used to verify its presence; mRNA was analyzed by northern blot with parallel experiments in mouse tissues, by RNase protection, and by in situ hybridization histochemistry. Bcl-2 protein was detected by western blot analysis and immunohistochemistry. Two bcl-2 mRNA species were identified in the human brain. The pattern of distribution of bcl-2 mRNA at the cellular level showed labeling in neurons but not glia. The in situ hybridization signal was stronger in the pyramidal neurons of the cerebral cortex and in the cholinergic neurons of the nucleus basalis of Meynert than in the Purkinje neurons of the cerebellum. Both melanized and nonmelanized neurons were labeled in the substantia nigra. In the striatum, bcl-2 mRNA was detected in some but not all neurons. In the regions examined for Bcl-2 protein, the expression pattern correlated with the mRNA results. In patients with Alzheimer's and Parkinson's diseases, quantification of bcl-2 mRNA in the nucleus basalis of Meynert and substantia nigra, respectively, showed that the expression was unaltered compared with controls, raising the possibility that the expression of other components of apoptosis is modulated.

The motor symptoms of Parkinson's disease (PD) (akinesia, rigidity, and tremor) very likely result from the progressive loss of substantia nigra pars compacta (SNpc) neurons, which produces a decreased dopamine concentration in the striatum. [1,2] This neuronal loss provokes a cascade of changes in the functioning of the basal ganglia; these changes are thought to participate in the development of this motor syndrome. Indeed, the activity of the output systems of the basal ganglia, represented by the internal segment of the pallidum (GPi) and the substantia nigra pars reticulata (SNpr), [3] is increased after nigrostriatal denervation. [4] However, although the hyperactivity of the GPi is well documented, this is not so for the activity of the SNpr. Furthermore, the SNpr differs from the GPi in terms of its (1) anatomic connections (afferent and efferent pathways) [5-7]; (2) biochemical content (methionine enkephalin and substance P) [8-10]; (3) direct contact with dendrites of the dopaminergic neurons of the SNpc, which may directly influence the activity of SNpr neurons [11,12]; and (4) involvement in the visuospatial and ocular motor function, resulting from its projection to the superior colliculus (SC), a structure related to the initiation of saccadic eye movements. [13,14] The goals of the present study were (1) to determine whether the SNpr is hyperactive after nigrostriatal denervation and (2) to analyze the possible functional consequences of any hyperactivity of the SNpr on the SC. Because SNpr efferent neurons use gamma-aminobutyric acid (GABA) as neurotransmitter, [15,16] we analyzed the consequences of nigrostriatal denervation on GABAergic activity in the SNpr of patients with PD and its effect on tectal GABAergic neurons. Since all PD patients had received L-dopa therapy, we tested the direct effect of nigrostriatal denervation on GABAergic activity in monkeys rendered parkinsonian by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) intoxication, some received L-dopa …

Treatment of gout and hyperuricemia can be difficult in patients with chronic renal failure. At present, there is no study available comparing the efficacy of the most widely used agent, allopurinol, and the uricosuric benzbromarone for the control of hyperuricemia in patients with renal insufficiency. We describe an open, randomized, actively controlled, comparative trial in patients with clearance of creatinine from 20 to 80 mL/ min/1.73 m(2). Patients were randomized to take benzbromarone (100-200 mg/day) or allopurinol (100-300 mg/day). Outcome variables were the following: reduction of serum urate (Sur), Sur & tl; 6 mg/dL (357 micromol/L), reduction of gouty bouts and reduction of tophi. During 9-24 months of follow-up 36 patients were studied.The reduction of Sur was higher with benzbromarone, and only 1 of 17 patients taking benzbromarone did not achieve Sur < 6 mg/dL versus 7 of 19 taking allopurinol. Patients who did not reach optimal Sur levels with allopurinol were more frequently taking diuretics and showed lower fractional excretion of urate and higher initial Sur levels than patients with proper control of Sur. Seven patients with suboptimal control of serum urate were changed to benzbromarone 100 mg/day, which showed efficacy similar in those who were initially randomized to benzbromarone. A reduction of gouty bouts and size of tophi was observed after proper control of Sur. Allopurinol is effective in controlling hyperuricemia, but patients with higher initial Sur levels or taking concomitant diuretic therapy are less prone to reach therapeutic goals.Benzbromarone is useful for the control of hyperuricemia in patients with renal insufficiency even with concomitant diuretic administration; patients benefited include those who previously had no improvement by taking allopurinol.

In most flowering plants, pollen is dispersed as monads. However, aggregated pollen shedding in groups of four or more pollen grains has arisen independently several times during angiosperm evolution. The reasons behind this phenomenon are largely unknown. In this study, we followed pollen development in Annona cherimola, a basal angiosperm species that releases pollen in groups of four, to investigate how pollen ontogeny may explain the rise and establishment of this character. We followed pollen development using immunolocalization and cytochemical characterization of changes occurring from anther differentiation to pollen dehiscence. Our results show that, following tetrad formation, a delay in the dissolution of the pollen mother cell wall and tapetal chamber is a key event that holds the four microspores together in a confined tapetal chamber, allowing them to rotate and then bind through the aperture sites through small pectin bridges, followed by joint sporopollenin deposition. Pollen grouping could be the result of relatively minor ontogenetic changes beneficial for pollen transfer or/and protection from desiccation. Comparison of these events with those recorded in the recent pollen developmental mutants in Arabidopsis indicates that several failures during tetrad dissolution may convert to a common recurring phenotype that has evolved independently several times, whenever this grouping conferred advantages for pollen transfer., Financial support for this work was provided by the Spanish Ministry of Science and Innovation (Project Grants AGL2004-02290/AGR, AGL2006-13529-C01, AGL2007-60130/AGR, AGL2008-04255 and BFU2008-00203), GIC-Aragón 43, Junta de Andalucía (AGR2742) and the European Union under the INCO-DEV program (Contract 015100). JL. was supported by a grant of the Junta de Andalucía. The authors thank K. Pinney for helpful suggestions to improve the manuscript.