Neostriatal muscarinic receptor subtypes involved in the generation of tremulous jaw movements in rodents implications for cholinergic involvement in parkinsonism

Several studies have shown that a number of pharmacological and neurochemical conditions in rats can induce jaw movements that are described as "vacuous" or "tremulous". For several years, there has been some debate about the clinical significance of various drug-induced oral motor syndromes. Nevertheless, considerable evidence now indicates that the non-directed, chewing-like movements induced by cholinomimetics have many of the characteristics of parkinsonian tremor. These movements are characterized largely by vertical deflections of the jaw, which occur in the same 3-7 Hz peak frequency that is typical of parkinsonian tremor. Cholinomimetic-induced tremulous jaw movements are suppressed by a number of different antiparkinsonian drugs, including scopolamine, benztropine, L-DOPA, apomorphine, bromocriptine, ropinirole, pergolide, amantadine, diphenhydramine and clozapine. A combination of anatomical and pharmacological research in rats has implicated M4 receptors in the ventrolateral neostriatum in the generation of tremulous jaw movements. Mice also show cholinomimetic-induced jaw movements, and M4 receptor knockout mice demonstrate subtantially reduced levels of jaw movement activity, as well as increased locomotion. Taken together, these data are consistent with the hypothesis that a centrally-acting M4 antagonist may be useful as a treatment for parkinsonian symptoms, including tremor.     

Atypical task-invariant organization of multi-segment tremors in patients with Parkinson’s disease during manual tracking

The objective of the study was to investigate the interplay between involuntary tremulous activities and task performance under volitional control for patients with Parkinson’s disease (PD) during position tracking. A volunteer sample of nine untreated patients and nine age-matched healthy subjects participated in this study. They performed a sinusoidal tracking maneuver with a shoulder and a static pointing task; meanwhile, a position trace of the index and accelerometer data in the upper limb were recorded to characterize tracking performance and postural–kinetic tremors. In reference to postural tremor, the kinetic tremor of control subjects during tracking was considerably modulated, leading to a lower regularity and greater spectral deviation. In contrast, patients with PD demonstrated greater postural and kinetic tremors than control subjects, and tremulous movements of the patients were comparatively task-invariant. The prominent coherence peak, which occurred at 8–12 Hz in control subjects, was atypically presented at 5–8 Hz for PD patients with poorer tracking performance. Functionally, congruency of position tracking was related to amplitude of kinetic tremor after subtracting from amplitude of postural tremor. In conclusion, task-dependent organization of tremulous movements was impaired in patients with PD. The inferior tracking performance of the patients correlated implicitly with kinetic tremor, signifying some sharing of neural substrates for manual tracking and tremor generation.     

Assessing the effect of complex ground types on ground‐dwelling arthropod movements with video monitoring: Dealing with concealed movements under a layer of plant residues

Understanding the effect of ground types on foraging movements of ground‐dwelling arthropods is a key step to managing their spatial distribution as required for successful conservation biological control. Indeed, fine movements at the centimeter scale can strongly influence the foraging ability of pest predators. However, because radio frequency identification or harmonic tracking techniques are not yet suitable for small species and video tracking focuses on uniform and light backgrounds, foraging movements have rarely been studied in relation to ground types. We present a method to track a ground‐dwelling arthropod (the earwig Euborellia caraibea) at night, walking on two contrasted ground types: bare soil and soil partly covered with a stratum of banana plant residues allowing individuals to hide periodically. The tracking of individuals within these ground types was achieved by infrared light, tagging individuals, video treatments, and semi‐automatic cleaning of trajectories. We tested different procedures to obtain segments with identical durations to quantify speeds and sinuosities. These procedures were characterized by the junction time gap between trajectory fragments, the rediscretization time of trajectories, and whether or not to use interpolation to fill in missing points in the trajectories. Earwigs exhibited significantly slower and more sinuous movements on soil with banana plant residues than on bare soil. Long time gaps for trajectory junction, extended rediscretization times, and interpolation were complementary means to integrate concealed movements in the trajectories. The highest slowdown in plant residues was detected when the procedure could account for longer periods under the residues. These results suggest that earwigs spent a significant amount of time concealed by the residues. Additionally, the residues strongly decreased the earwigs'' movement. Since the technical solutions presented in this study are inexpensive, easy to set up, and replicate, they represent valuable contributions to the emerging field of video monitoring.     

Short interval leaf movements of cotton

Gossypium hirsutum L. cv. Lankart plants exhibited three different types of independent short interval leaf movements which were superimposed on the circadian movements. The different types were termed SIRV (short interval rhythmical vertical), SIHM (short interval horizontal movements), and SHAKE (short stroked SIRV). The 36-minute period SIRV movements occurred at higher moisture levels. The 176-minute period SIHM occurred at lower moisture levels and ceased as the stress increased. The SHAKE movements were initiated with further stresses. The SLEEP (circadian, diurnal) movements ceased with further stress. The last to cease just prior to permanent wilting were the SHAKE movements.     

Hypoglossal-facial nerve anastomosis for reinnervation of the paralyzed face.

The hypoglossal-facial nerve crossover is a valuable surgical procedure for the treatment of certain types of facial paralysis. It is most effective when used as an integral part of a primary ablative operation for the treatment of cancer in this region. In the treatment of long-standing facial paralysis, its application requires an intact peripheral facial nerve system and some functioning mimetic muscles with an obliterated proximal facial nerve segment. It is recognized that other procedures are available for repair in patients who meet essentially these same criteria. The disadvantages are minimal intraoral crippling, mass movements of the face and, in some instances, hypertonia of the face. The advantages are improved facial tone, protection of the eye, intentional facial movements controlled by the tongue, and movements associated with physiological functions of the tongue.     

Conditioned Whisking in the Rat

The rat's mystacial vibrissae are active during exploratory and discriminative behaviors, with individual vibrissae serving as elements in a receptive array scanned across object surfaces. To facilitate neurobehavioral analysis of this sensorimotor system, we have developed an experimental paradigm that confines vibrissa movements to a defined physical location, makes possible on-line monitoring of “whisking” activity, and brings such activity under associative control using operant conditioning procedures. Rats were secured, and movements of an identified bilaterally homologous pair of vibrissae (right and left gamma straddlers) were detected by laser-based photodetectors. Subjects were maintained on a water deprivation schedule, and whisker movements were monitored during adaptation to the test situation and after the clipping of other vibrissae on both sides of the snout. Rats were reinforced with water delivery for emitting vibrissa movements in the presence of a conditioned stimulus (tone) whose presentation was made contingent upon a prior period of nonwhisking. The rate and temporal distribution of vibrissa movements were brought under experimental control by means of interval and ratio reinforcement schedules. Although the procedures provide minimal information about the kinematics or topography of conditioned vibrissa movements, they permit the investigator to manipulate response parameters normally under the voluntary control of the animal in a preparation amenable to neurophysiological analysis     

Abatement by acetate of an ethanol withdrawal syndrome

Acetate, the main end product of ethanol metabolism in the liver and a substrate of the cerebral small-pool Krebs-cycle, was tested for its ability to abate an ethanol withdrawal syndrome. Male Sprague-Dawley derived rats were rendered physically dependent on ethanol by intragastric administration of ethanol at a dosage of 9 to 15 grams per kilogram per day over a 4-day period. Oral administration of acetate was effective in abating the tremulous component of the ethanol withdrawal syndrome.     

Suppression of an ethanol withdrawal syndrome in rats by butyrate, lactate and beta-hydroxybutyrate

Butyrate, lactate and beta-hydroxybutyrate, compounds which may be elevated in blood of ethanol dependent rats and substrates of the cerebral small-pool Krebs-cycle, were tested for their ability to suppress an ethanol withdrawal syndrome. Male Sprague-Dawley rats were rendered physically dependent on ethanol by intragastric administration of ethanol at a dosage of 9 to 15 grams per kilogram per day over a 4-day period. Oral administration of a mixture of butyrate, lactate and beta-hydroxybutyrate was effective in suppressing the tremulous component of the ethanol withdrawal syndrome.     

Development and application of methods for investigating the ratio of rheoreaction types of fish in a circular tank

Methods for evaluating the motivational component of the fish rheoreaction (ratio of rheoreaction types) are developed and tested in a circular hydrodynamic tank for three fish species (Danio rerio, Poecilia reticulata, and Inpaichthys kerri). Three rheoreaction types of fish were distinguished: a positive type (fish movements against water current), a negative type (fish movements along with water current), and a compensatory type (fish maintaining their position in relation to immobile reference points). The main distinguishing features of these new methods are unrestricted distance for fish movements, continuous monitoring of individual fish movements (video recording), and evaluation of ratio between the types of rheoreaction in terms of duration of demonstration of these types by each. The minimum required observation time and water current velocities are determined. It is shown that these methods can be used for investigating the types of rheoreaction in different fish species. Every single individual repeatedly demonstrated all these three rheoreaction types during the test.     

Examination of the λ equilibrium point hypothesis when applied to single degree of freedom movements performed with different inertial loads

 One of the theories of human motor control is the λ Equilibrium Point Hypothesis. It is an attractive theory since it offers an easy control scheme where the planned trajectory shifts monotionically from an initial to a final equilibrium state. The feasibility of this model was tested by reconstructing the virtual trajectory and the stiffness profiles for movements performed with different inertial loads and examining them. Three types of movements were tested: passive movements, targeted movements, and repetitive movements. Each of the movements was performed with five different inertial loads. Plausible virtual trajectories and stiffness profiles were reconstructed based on the λ Equilibrium Point Hypothesis for the three different types of movements performed with different inertial loads. However, the simple control strategy supported by the model, where the planned trajectory shifts monotonically from an initial to a final equilibrium state, could not be supported for targeted movements performed with added inertial load. To test the feasibility of the model further we must examine the probability that the human motor control system would choose a trajectory more complicated than the actual trajectory to control. Received: 20 June 1995 / Accepted in revised form: 6 August 1996     

The Effects of Rhythmicity and Amplitude on Transfer of Motor Learning

We perform rhythmic and discrete arm movements on a daily basis, yet the motor control literature is not conclusive regarding the mechanisms controlling these movements; does a single mechanism generate both movement types, or are they controlled by separate mechanisms? A recent study reported partial asymmetric transfer of learning from discrete movements to rhythmic movements. Other studies have shown transfer of learning between large-amplitude to small-amplitude movements. The goal of this study is to explore which aspect is important for learning to be transferred from one type of movement to another: rhythmicity, amplitude or both. We propose two hypotheses: (1) Rhythmic and discrete movements are generated by different mechanisms; therefore we expect to see a partial or no transfer of learning between the two types of movements; (2) Within each movement type (rhythmic/discrete), there will be asymmetric transition of learning from larger movements to smaller ones. We used a learning-transfer paradigm, in which 70 participants performed flexion/extension movements with their forearm, and switched between types of movement, which differed in amplitude and/or rhythmicity. We found partial transfer of learning between discrete and rhythmic movements, and an asymmetric transfer of learning from larger movements to smaller movements (within the same type of movement). Our findings suggest that there are two different mechanisms underlying the generation of rhythmic and discrete arm movements, and that practicing on larger movements helps perform smaller movements; the latter finding might have implications for rehabilitation.     

Behavior and fine structure of spindle fibers during mitosis in endosperm

Endosperm ofHaemanthus katherinae has been used as material. Changes in arrangement of spindle fibers, their movements, and behavior of substructures as seen in living cells with the Nomarski system are described. The same cell has been observed with the light microscope and subsequently after the usual procedures with the electron microscope. Arrangement of microtubules forming different types of spindle fibers and their relation to each other during the progress of mitosis is described. Kinetochore structure has also been studied. It is suggested that kinetochore fibers are transported to the poles during anaphase. This conclusion is supported by fine structure studies.     

Study of different kinds of locomotor movements in rats

The kinematics and electromyographic activity of the hind limb muscles of intact rats fixed in a special frame were investigated during locomotor movements of different kinds. A change in the external conditions determining the degree of limb loading (the presence or absence of support, and so on) was shown to lead to changes in the pattern and (or) amplitude of the movements. Six types of locomotion were distinguished, and in accordance with the kinematics of the hind limb movements these can be divided into two types: swimming and stepping. The analysis showed marked variability of the parameters (frequency, duration of the swing phase and of the support phase) of the different locomotor movements.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 17, No. 2, pp. 183–189, March–April, 1985.     

Protective movements during sideways falls from standing height

To examine the effect of protective movements during sideways falls from standing height (i.e., from the standing position), a two-step study was performed. In the first step, 80 young male and female volunteers freely fell onto a sport-mat. All falls were recorded on videotape, and replayed to analyze movements in response to the falls. Several protective movements were observed; forward flexion and lateral flexion were observed with a particularly high frequency. In the second step, impact velocities of the head and hip were measured by a three-dimensional motion analyzer regarding three types of falls: stiff falls, forward flexion falls and lateral flexion falls. Both types of flexion reduced impact velocities of the head, but not those of the hip. The reduction of the impact velocity on the head correlated with the lowering of the height of the head from the floor.     

Control of human eye movements: II. a model for the extraocular plant mechanism

Control of eye movements is essential in accomplishing visual or perceptive tasks. The brain and central nervous system process retinal information and send nervous signals to the extraocular muscles, which exert forces that cause the eye to move. A model for the human extraocular plant, which consists of the nervous input signals, the extraocular muscles, the orbit and the globe, is proposed. The derivation is based on anatomical and physiological data as well as experiments concerned with a variety of eye movements under normal and abnormal conditions. The nervous activity controlling eye movements was estimated from electromyography and single unit studies of the extraocular nuclei. The equations describing muscle properties were discussed in a previous paper by the authors; these results were incorporated into the present model. The characteristics of the isolated globe and its visco-elastic interaction with the orbit were computed from length- tension curves and isotonic experiments. Simulations using the resulting representation accurately depicted the isotonic experiments on the isolated globe and on the total extraocular plant, the isometric forces during three different types of eye movements, and the weighted globe experiment. A future paper will show that the model accurately simulates normal eye movements of different types and amplitudes.     

Monitoring Escape and Feeding Behaviours of Cruiser Fish by Inertial and Magnetic Sensors

A method was developed and applied for monitoring two types of fast-start locomotion (feeding and escape) of a cruiser fish, Japanese amberjacks Seriola quinqueradiata. A data logger, which incorporated a 3-axis gyroscope, a 3-axis accelerometer and a 3-axis magnetometer, was attached to the five fish. The escape, feeding and routine movements of the fish, which were triggered in tank experiments, were then recorded by the data logger and video cameras. The locomotor variables, calculated based on the high resolution measurements by the data logger (500 Hz), were investigated to accurately detect and classify the types of fast-track behaviour. The results show that fast-start locomotion can be detected with a high precision (0.97) and recall rate (0.96) from the routine movements. Two types of fast-start movements were classified with high accuracy (0.84). Accuracy was greater if the data were obtained from the data logger, which combined an accelerometer, a gyroscope and a magnetometer, than if only an accelerometer (0.80) or a gyroscope (0.66) was used.     

The Cartagena Protocol on Biosafety and living modified fish

The Cartagena Protocol on Biosafety is an international treaty under the Convention on Biological Diversity that promotes biosafety by establishing practical rules and procedures for the safe transfer, handling and use of living modified organisms (LMOs), with a specific focus on regulating transboundary movements of these organisms from one country to another. The Protocol includes the advance informed agreement procedure which sets rules on how Parties should take decisions regarding the transboundary movement of LMOs for intentional introduction into the environment, including living modified fish for biocontrol of non-native and invasive species. The advance informed agreement procedure places great emphasis on risk assessment and the Protocol includes an annex with general principles, methodological steps and points to consider when conducting a risk assessment. In recent years, the Parties to the Protocol have begun to develop guidance on risk assessment for specific types of LMOs although they have not, to date, specifically addressed living modified fish. Other relevant aspects of the Protocol include its provisions on unintentional and illegal transboundary movements; the handling, transport, packaging and identification of LMOs; and liability and redress.     

Dynamics of neuronal interaction in the human thalamic nucleus reticularis produced by significant and non-significant verbal stimuli

Dynamics of neuronal interaction recorded by microelectrodes were examined in 90 arrays of cells of the human thalamic reticular nucleus (Rt) during stereotaxic surgical procedures. Cooperative interaction between adjacent neurons was found to occur in neuronal arrays after presentation of verbal (or sensory-cum-acoustic) functionally significant stimulus (FSS) as well as at stages of initiation and performance of goal-directed movement. Specialized dynamics were noted in the pattern of interaction between neuronal arrays of two types (A and B) with irregular background activity and 2–5 Hz bursting rhythm (types A and B respectively). This dynamic local neuronal interaction correlates with the stage of significant verbal stimulus presentation and that of performing goal-directed movements. The matching transient correlation between activity of A and B cell arrays reflects matching operation of two sequences of regulatory and control processes involved in processing of functionally significant verbal (or sensory) information and performance of goal-directed movement.Institute of Chemical Physics, Academy of Sciences of the USSR, Moscow Institute of Neurosurgery, Academy of Medical Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 22, No. 4, pp. 451–459, June–July, 1990.     

A stochastic model of the distribution of unequal competitors between resource patches

We present a stochastic model of individuals' movements between two patches of resources. The population is made up of two types of individual with differing competitive abilities, and two types of movements occur, with individuals moving either to increase their intake rate or at random. Several previous models have used simulations to evaluate the likely distribution of individuals. We instead derive equations for the equilibrium distribution of the population, which can be solved numerically. This avoids the need to choose an initial distribution for the population, and enables us to obtain the probability with which rare events occur. This may not be possible when simulations are used, since a rare event may not occur at all. We find that when random movements are rare, an increase in the rate of random movements out of a patch can increase the number of individuals on that patch. We consider an approximation to the model with rare random movements, which provides an explanation for this phenomenon.     

Dispersal behaviour in fragmented landscapes: Routine or special movements?

Dispersal is a key process in ecology, evolutionary and conservation biology. Studies like mark-release-recapture work, show patterns of movement, but do not provide insight into the behavioural mechanisms. We review and comment recent results on animal dispersal behaviour. Dispersal through a landscape can be realised in two different ways: as a by-product of routine movements associated with resource exploitation (like foraging or mate-searching) with high levels of returning, or, as special, fast and directed movements designed for displacement. We illustrate and discuss both classes of movements as behaviourally different types. These types of movement imply different assumptions and consequences. We point at potential biases of current studies (like mark-release-recapture studies) towards routine, explorative movements. A more accurate knowledge of the dispersal behaviour is important to model dispersal with more biological realism, but also to better understand evolutionary consequences (e.g. uncoupled evolution of routine and special movements) and conservation (e.g. relative importance of corridors). The contribution of routine movements to dispersal is expected to decline with habitat fragmentation. A species’ mobility is not a static trait, but a multiple trait, the components of which may evolve rapidly. The possibility of uncoupled selection on routine movements and real dispersal movements remains to be evaluated. Yet, we are only at the beginning of understanding the behavioural ecology of dispersal movements. A more careful treatment of behavioural components of mobility within observational and experimental studies of animal dispersal is needed.