The Dopaminergic Control of Movement-Evolutionary Considerations

Dopamine is likely the most studied modulatory neurotransmitter, in great part due to characteristic motor deficits in Parkinson’s disease that arise after the degeneration of the dopaminergic neurons in the substantia nigra pars compacta (SNc). The SNc, together with the ventral tegmental area (VTA), play a key role modulating motor responses through the basal ganglia. In contrast to the large amount of existing literature addressing the mammalian dopaminergic system, comparatively little is known in other vertebrate groups. However, in the last several years, numerous studies have been carried out in basal vertebrates, allowing a better understanding of the evolution of the dopaminergic system, especially the SNc/VTA. We provide an overview of existing research in basal vertebrates, mainly focusing on lampreys, belonging to the oldest group of extant vertebrates. The lamprey dopaminergic system and its role in modulating motor responses have been characterized in significant detail, both anatomically and functionally, providing the basis for understanding the evolution of the SNc/VTA in vertebrates. When considered alongside results from other early vertebrates, data in lampreys show that the key role of the SNc/VTA dopaminergic neurons modulating motor responses through the basal ganglia was already well developed early in vertebrate evolution.

Social Symptoms of Parkinson’s Disease

Parkinson’s disease (PD) is typically well recognized by its characteristic motor symptoms (e.g., bradykinesia, rigidity, and tremor). The cognitive symptoms of PD are increasingly being acknowledged by clinicians and researchers alike. However, PD also involves a host of emotional and communicative changes which can cause major disruptions to social functioning. These incude problems producing emotional facial expressions (i.e., facial masking) and emotional speech (i.e., dysarthria), as well as difficulties recognizing the verbal and nonverbal emotional cues of others. These social symptoms of PD can result in severe negative social consequences, including stigma, dehumanization, and loneliness, which might affect quality of life to an even greater extent than more well-recognized motor or cognitive symptoms. It is, therefore, imperative that researchers and clinicans become aware of these potential social symptoms and their negative effects, in order to properly investigate and manage the socioemotional aspects of PD. This narrative review provides an examination of the current research surrounding some of the most common social symptoms of PD and their related social consequences and argues that proactively and adequately addressing these issues might improve disease outcomes.

Molecular Mechanisms and Clinical Manifestations of Catecholamine Dysfunction in the Eye in Parkinson’s Disease As a Basis for Developing Early Diagnosis

This review provides information onthe non-motor peripheral manifestations of Parkinsons disease (PD) associated with a pathology of the visual analyzer and the auxiliary apparatus of the eye. The relationship between neurodegenerative processes that take place in the brain and in the eye opens new prospects to use preventive ophthalmologic examination todiagnose PD long before the characteristic motor symptoms appear. This will encourage the use of neuroprotective therapy, which stops, or at least slows down, neuronal death, instead of the current replacement therapy with dopamine agonists. Animportant result of an eye examination of patients with PD may be a non-invasive identification of new peripheral biomarkers manifesting themselvesas changes in the composition of the lacrimal fluid.

Social Symptoms of Parkinson’s Disease

Parkinson’s disease (PD) is typically well-recognized by its characteristic motor symptoms (e.g., bradykinesia, rigidity, and tremor). The cognitive symptoms of PD are increasingly being acknowledged by clinicians and researchers alike. However, PD also involves a host of emotional and communicative changes which can cause major disruptions to social functioning. These include problems producing emotional facial expressions (i.e., facial masking) and emotional speech (i.e., dysarthria), as well as difficulties recognizing the verbal and non-verbal emotional cues of others. These social symptoms of PD can result in severe negative social consequences, including stigma, dehumanization, and loneliness, which might affect quality of life to an even greater extent than more well-recognized motor or cognitive symptoms. It is therefore imperative that researchers and clinicians become aware of these potential social symptoms and their negative effects, in order to properly investigate and manage the socioemotional aspects of PD. The present review provides an examination of the current research surrounding some of the most common social symptoms of PD and their related social consequences, and argues that proactively and adequately addressing these issues might improve disease outcomes.

The effect of haloperidol, aminooxyacetic acid and (-)-nuciferine on prolonging survival time of mice with tetanus

Introduction. Tetanus, also known as lockjaw, is a very dangerous, infectious, acute, usually afebrile disease characterised by muscle spasms. The causative agent of the disease is the bacterium Clostridium tetani. This pathogen produces a specific neurotoxin, termed tetanus toxin, with two components: tetanospasmin and tetanolysin. Light chains of tetanospasmin cleavage synaptobrevin, which in turn prevent release of the inhibitory neurotransmitter GABA into the synaptic cleft. The ?-motor neurons are, therefore, under no inhibitory control, as a result of which they undergo sustained excitatory discharge causing the characteristic motor spasms of tetanus. Materials and Methods. In this research, we attempted to normalise disorders caused by tetanus toxin by using haloperidol (at doses of 4, 5, 6, 7 and 8 mg/kg b.w.), alone and in combination with (-)-nuciferine (at a dose of 5 mg/kg b.w.) or aminooxyacetic acid (at a dose of 20 mg/kg b.w.). Experiments were conducted on albino mice. Experimental tetanus was induced by application of tetanus toxin. Results and Conclusions. Application of haloperidol (alone and in combination with (-)-nuciferine and aminooxyacetic acid) was carried out 24 h following the application of tetanus toxin. It was found that haloperidol, given alone in a dose of 4 mg/kg, prolonged the average survival time of mice with experimental tetanus by 24.35 h compared to the control animals. Additionally, the combination of haloperidol with (-)-nuciferine slightly, but non-significantly, extended survival time , while the combination of haloperidol with aminooxyacetic acid produced the best effect on extension of survival time (mice survived on average 27.74 h longer than control mice).

Facets of Pantomime

Objectives: Exploring the nature of defective pantomime in apraxia. Methods: Critical review of behavioral associations and dissociations between defective pantomime, imitation of gestures, and real tool use. Analysis of congruencies between crucial lesions for pantomime, imitation, and tool use. Results: There are behavioral double dissociations between pantomime and imitation, and their cerebral substrates show very little overlap. Whereas defective pantomime is bound to temporal and inferior frontal lesions, imitation is mainly affected by parietal lesions. Pantomime usually replicates the motor actions of real use but on scrutiny there are important differences between the movements of real use and of pantomime that cast doubt on the assumption that pantomime is produced by the same motor programs as actual use. A more plausible proposal posits that pantomime is a communicative gesture that uses manual actions for conveying information about objects and their use. The manual actions are constructed by selection and combination of distinctive features of tools and actions. They frequently include replications of characteristic motor actions of real use, but the main criterion for selection and modification of features is the comprehensibility of the gestures rather than the accurate replication of the motor actions of real use. Conclusions: Pantomime of tool use is a communicative gesture rather than a replication of the motor actions of real use. (JINS, 2017, 23, 121–127)

SPECT Molecular Imaging in Parkinson's Disease

Parkinson's disease (PD) is a common disorder, and the diagnosis of Parkinson's disease is clinical and relies on the presence of characteristic motor symptoms. The accuracy of the clinical diagnosis of PD is still limited. Functional neuroimaging using SPECT technique is helpful in patients with first signs of parkinsonism. The changes detected may reflect the disease process itself and/or compensatory responses to the disease, or they may arise in association with disease- and/or treatment-related complications. This paper addresses the value of SPECT in early differential diagnosis of PD and its potential as a sensitive tool to assess the pathophysiology and progression, as well as the therapeutic efficacy of PD.