The origins and early history of neurochemistry and its societies.

At the 2017 joint meeting of the International Society for Neurochemistry (ISN) and the European Society for Neurochemistry, 150 years of neurochemistry - the 50th anniversary of ISN, 40 years of European Society for Neurochemistry, and 60 years of the Journal of Neurochemistry (JNC) - was celebrated with a historical symposium that explored the foundations of neurochemical societies, key international figures in the discipline of neurochemistry, and the pre-eminent role of the JNC. The foundations of neurochemistry were laid in Europe, notably France and Germany, in the late 18th and early 19th centuries. Neurochemists in the United Kingdom made globally relevant contributions before and after the Second World War, and Swedish contributions were especially prominent in the 1950s and 1960s. As neurochemistry is a truly international branch of neuroscience, the important contributions of neurochemists in the Americas and the Asia-Pacific were also recognized, as were the seminal roles of the American, Asia-Pacific, and Japanese Societies of Neurochemistry. Although ISN was only formed in 1967, earlier international meetings in Europe and the Americas reflected the growing recognition of the importance of chemistry and biochemistry for understanding and responding to the pathophysiology of clinical conditions and diseases of the central and peripheral nervous systems. JNC was first published in 1956, but the ISN only assumed complete ownership of the journal under tempestuous circumstances in 1970. The ISN-JNC interface and the sterling work of the JNC Editors has meant that the income generated by the journal has allowed the ISN Council to implement diverse programs for supporting neurochemistry internationally, including sustaining regional neurochemical societies, and supporting neurochemists in the developing world and schools of neurochemistry.

Soups and Sparks Revisited John Eccles' Path from the War on Electrical Transmission to Mental Sparks.

In the famous debate whether neurons communicate via chemical mediators or electrical signals, Henry Dale and Otto Loewi mounted powerful evidence on the mediation of nervous activity by chemical transmitters, while John Eccles led the campaign for the electrophysiologists. Eventually, Eccles converted to chemical transmission, when he identified excitatory and inhibitory postsynaptic potentials initiated by the release of chemical neurotransmitters in the synaptic cleft. This well-known episode from the history of neurophysiology counts as a rare instance of philosophy of science advancing scientific research, because the philosopher Karl Popper had encouraged Eccles to theorize an experiment proving the falsity of his own interpretation ­ according to Popper's philosophy of science progressing by falsification. The paper shows how Eccles' intellectual mobilization was grounded in a series of geographical moves, technological adaptations and re-arrangements of his group. This massive travel of people, ideas, instruments, and techniques mediated between the contradictory views, long before Popper kindled Eccles to reflect about the conflicting paradigms and the new theorizing did hardly change his experimental practice. Popper's immediate effect was a critical and reflexive distance that enabled Eccles to present his evidence more persuasively, as can be shown from archival sources. The exchanges between Eccles and Popper thus shaped the philosophy of falsification to a powerful strategy for writing science.

La neurohormona GnRH en la mujer / Neurohormone GnRH in the woman

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CNS drug development: lessons from the development of ondansetron, aprepitant, ramelteon, varenicline, lorcaserin, and suvorexant. Part I.

This column is the first in a two-part series exploring lessons for psychiatric drug development that can be learned from the development of six central nervous system drugs with novel mechanisms of action over the past 25 years. Part 1 presents a brief overview of the neuroscience that supported the development of each drug, including the rationale for selecting a) the target, which in each case was a receptor for a specific neurotransmitter system, and b) the indication, which was based on an understanding of the role that target played in a specific neural circuit in the brain. The neurotransmitter systems on which the development of these agents were based included serotonin for ondansetron and lorcaserin, dopamine for varenicline, substance P (or neurokinin) for aprepitant, melatonin for ramelteon, and orexin for suvorexant. The indications were chemotherapy-induced nausea and vomiting for ondansetron and aprepitant, smoking cessation for varenicline, weight loss for lorcaserin, and insomnia for suvorexant and ramelteon.

Differential responses of components of the autonomic nervous system.

This chapter conveys several concepts and points of view about the scientific and medical significance of differential alterations in activities of components of the autonomic nervous system in stress and disease. The use of terms such as "the autonomic nervous system," "autonomic failure," "dysautonomia," and "autonomic dysfunction" imply the existence of a single entity; however, the autonomic nervous system has functionally and neurochemically distinctive components, which are reflected in differential responses to stressors and differential involvement in pathophysiologic states. One can conceptualize the autonomic nervous system as having at least five components: the sympathetic noradrenergic system, the sympathetic cholinergic system, the parasympathetic cholinergic system, the sympathetic adrenergic system, and the enteric nervous system. Evidence has accumulated for differential noradrenergic vs. adrenergic responses in various situations. The largest sympathetic adrenergic system responses are seen when the organism encounters stressors that pose a global or metabolic threat. Sympathetic noradrenergic system activation dominates the responses to orthostasis, moderate exercise, and exposure to cold, whereas sympathetic adrenergic system activation dominates those to glucoprivation and emotional distress. There seems to be at least as good a justification for the concept of coordinated adrenocortical-adrenomedullary responses as for coordinated adrenomedullary-sympathoneural responses in stress. Fainting reactions involve differential adrenomedullary hormonal vs. sympathetic noradrenergic activation. Parkinson disease entails relatively selective dysfunction of the sympathetic noradrenergic system, with prominent loss of noradrenergic nerves in the heart, yet normal adrenomedullary function. Allostatic load links stress with degenerative diseases, and Parkinson disease may be a disease of the elderly because of allostatic load.

[From shock therapies to new neuromodulation techniques]. / Des thérapies de choc aux nouvelles techniques de neuromodulation.

The first shock therapies date back to 1933 with the Sakel therapy. Electric induction experiments led to electroconvulsive therapy first used by Ugo Cerletti and Lucio Bini in 1938. Today, transcranial magnetic stimulation offers new therapeutic perspectives for the treatment of mental disorders. Similarly, deep brain stimulation techniques have been developed for the treatment of compulsive obsessive disorders and severe and treatment-resistant depression.

Scopoli's work in the field of mercurialism in light of today's knowledge: past and present perspectives.

The Idrija Mercury Mine (1490-1994) appointed its first physician, Joannes Antonius Scopoli, in 1754. Most of his descriptions of mercurialism are still relevant today. This study highlights Scopoli's observations on the interaction between elemental mercury (Hg degrees ) and alcohol, on the appearance of lung impairment, insomnia, and depressive mood in mercurialism. This presentation is based on Scopoli's experiences presented in his book, De Hydrargyro Idriensi Tentamina (1761), current knowledge, and our own experience acquired through health monitoring of occupational Hg degrees exposure. Some studies have confirmed Scopoli's observation that alcohol enhances mercurialism and his hypothesis that exposure to high Hg degrees concentrations causes serious lung impairment. Neurobiological studies have highlighted the influence of Hg degrees on sleep disorder and depressive mood observed by Scopoli. Although today's knowledge provides new perspectives of Scopoli's work on mercurialism, his work is still very important and can be considered a part of occupational medicine heritage.

Acetylcholine--from Vagusstoff to cerebral neurotransmitter.

This paper is concerned with some of the events in physiology that followed Otto Loewi's description of a substance that he named "Vagusstoff"; events that led eventually to the establishment of acetylcholine as a transmitter substance in the nervous system. Much of the work achieving this recognition of acetylcholine as a neurotransmitter took place in the middle third of the twentieth century; a period that witnessed the dislocation of many people as a result of National Socialist policies in Germany, that country's expansionist conquests, and the Second World War. A few of the people who were obliged to emigrate from Europe played prominent roles in these discoveries. This paper describes some of their achievements and, in a way, pays tribute to them.

Towards a clinical methodology for neuropsychopharmacological research.

Neuropsychopharmacology is dedicated to the study of the pathophysiology and treatment of mental pathology with the employment of centrally acting drugs. In neuropsychopharmacological research the clinical effects of a psychotropic drug are linked to the effects of the substance on brain structures involved in its mode of action. It is assumed, that knowledge about the mode of action of a selectively effective psychotropic drug will provide clues about the pathophysiology of the illness, and conversely, that knowledge about the pathophysiology of an illness, will provide clues for developing clinically more effective psychotropic drugs. Since the currently employed clinical methodology for the demonstration of therapeutic efficacy links the mode of action of psychotropic drugs to pharmacologically heterogeneous populations, neuropsychopharmacological research does not provide the necessary feedback for developing more effective drugs. To resolve the pharmacological heterogeneity within currently used diagnoses, attempts were made to split syndrome-based psychiatric diagnoses into discrete neurobiological deficits, and to replace traditional psychiatric nosology by a genetic psychiatric nosology. Yet, to date, there is no alternative methodology to psychopathology-based psychiatric nosology for classifying mental pathology in a clinically relevant manner. As we are moving from the "neurotransmitter era" to a "genetic era" in neuropsychopharmacology, the need for identifying pharmacologically homogenous populations is becoming imminent. All primary targets of psychotropic drugs in the brain are encoded by genes which are identified, and any nosologic entity or psychiatric syndrome that corresponds with a treatment responsive population is a candidate for the generation of genetic hypotheses relevant to mental illness. Recognition that progress in neuropsychopharmacology, and molecular genetic research, depends on the speed clinical research can resolve the pharmacological heterogeneity within currently used diagnoses, led to the development of methodologies for the identification of treatment responsive form(s) of illness, such as the Composite Diagnostic Evaluation (CODE) System, and nosologic homotyping. The CODE System is a methodology for the identification of treatment responsive forms of illness if covered up by consensus-based diagnoses; it consists of a set of diagnostic algorithms that can assign simultaneously a diagnosis from several classifications to a patient. Nosologic homotypes are identical in elementary units of mental illness and are assigned the same position in the nosologic matrix, based on three "nosologic organizing principles. The empirically derived diagnostic categories are suitable for testing hypotheses relevant to the relationship between the "processing of mental events" and "signal transduction" in the central nervous system.

Turning off neurotransmitters.

The historic discovery that the catecholamine neurotransmitters of the sympathetic nervous system, norepinephrine and epinephrine, are inactivated through their reuptake by presynaptic nerve terminals provided new insights into neurotransmitter action and paved the way for the development of modern antidepressant drugs.

The glutamate story.

Glutamatergic synaptic transmission in the mammalian central nervous system was slowly established over a period of some 20 years, dating from the 1950s. Realisation that glutamate and like amino acids (collectively known as excitatory amino acids (EAA)) mediated their excitatory actions via multiple receptors preceded establishment of these receptors as synaptic transmitter receptors. EAA receptors were initially classified as N-methyl-D-aspartate (NMDA) and non-NMDA receptors, the latter subdivided into quisqualate (later AMPA) and kainate receptors after agonists that appeared to activate these receptors preferentially, and by their sensitivity to a range of differentially acting antagonists developed progressively during the 1970s. NMDA receptors were definitively shown to be synaptic receptors on spinal neurones by the sensitivity of certain excitatory pathways in the spinal cord to a range of specific NMDA receptor antagonists. Importantly, specific NMDA receptor antagonists appeared to be less effective at synapses in higher centres. In contrast, antagonists that also blocked non-NMDA as well as NMDA receptors were almost universally effective at blocking synaptic excitation within the brain and spinal cord, establishing both the existence and ubiquity of non-NMDA synaptic receptor systems throughout the CNS. In the early 1980s, NMDA receptors were shown to be involved in several central synaptic pathways, acting in concert with non-NMDA receptors under conditions where a protracted excitatory postsynaptic potential was effected in response to intense stimulation of presynaptic fibres. Such activation of NMDA receptors together with non-NMDA receptors led to the phenomenon of long-term potentiation (LTP), associated with lasting changes in synaptic efficacy (synaptic plasticity) and considered to be an important process in memory and learning. During the 1980s, it was shown that certain glutamate receptors in the brain mediated biochemical changes that were not susceptible to NMDA or non-NMDA receptor antagonists. This dichotomy was resolved in the early 1990s by the techniques of molecular biology, which identified two families of glutamate-binding receptor proteins (ionotropic (iGlu) and metabotropic (mGlu) receptors). Development of antagonists binding to specific protein subunits is currently enabling precise identification of discrete iGlu or mGlu receptor subtypes that participate in a range of central synaptic processes, including synaptic plasticity.

GABA and glycine as neurotransmitters: a brief history.

gamma-Aminobutyric acid (GABA) emerged as a potentially important brain chemical just over 50 years ago, but its significance as a neurotransmitter was not fully realized until over 16 years later. We now know that at least 40% of inhibitory synaptic processing in the mammalian brain uses GABA. Establishing its role as a transmitter was a lengthy process and it seems hard to believe with our current knowledge that there was ever any dispute about its role in the mammalian brain. The detailed information that we now have about the receptors for GABA together with the wealth of agents which facilitate or reduce GABA receptor mechanisms make the prospects for further research very exciting. The emergence of glycine as a transmitter seems relatively painless by comparison to GABA. Perhaps this is appropriate for the simplest of transmitter structures! Its discovery within the spinal cord and brainstem approximately 40 years ago was followed only 2 years later by the proposal that it be conferred with 'neurotransmitter' status. It was another 16 years before the receptor was biochemically isolated. Now it is readily accepted as a vital spinal and supraspinal inhibitory transmitter and we know many details regarding its molecular structure and trafficking around neurones. The pharmacology of these receptors has lagged behind that of GABA. There is not the rich variety of allosteric modulators that we have come to readily associate with GABA receptors and which has provided us with a virtual treasure trove of important drugs used in anxiety, insomnia, epilepsy, anaesthesia, and spasticity, all stemming from the actions of the simple neutral amino acid GABA. Nevertheless, the realization that glycine receptors are involved in motor reflexes and nociceptive pathways together with the more recent advent of drugs that exhibit some subtype selectivity make the goal of designing selective therapeutic ligands for the glycine receptor that much closer.

Acetylcholine.

This article traces the development of knowledge about the physiology and pharmacology of acetylcholine and its receptors between 1930 and 2005, with emphasis on contributions by members of the British Pharmacological Society, and by other British pharmacologists and physiologists.

Purinergic signalling.

While there were early papers about the extracellular actions of purines, the role of ATP as a purinergic neurotransmitter in nonadrenergic, noncholinergic nerves in the gut and bladder in 1972 was a landmark discovery, although it met considerable resistance for the next 20 years. In the early 1990s, receptors for purines were cloned: four P1 receptor subtypes and seven P2X ionotropic and eight P2Y metabotropic receptor subtypes are currently recognized and characterized. The mechanisms underlying ATP release and breakdown are discussed. Purines and pyrimidines have major roles in the activities of non-neuronal cells as well as neurons. This includes fast signalling roles in exocrine and endocrine secretion, platelet aggregation, vascular endothelial cell-mediated vasodilation and nociceptive mechanosensory transduction, as well as acting as a cotransmitter and neuromodulator in most, if not all, nerve types in the peripheral and central nervous systems. More recently, slow (trophic) purinergic signalling has been implicated in cell proliferation, migration, differentiation and death in embryological development, wound healing, restenosis, atherosclerosis, ischaemia, cell turnover of epithelial cells in skin and visceral organs, inflammation, neuroprotection and cancer.