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PubMed1981

[Synaptic excitation of reticulospinal neurons during the startle reaction in cats anesthetized with chloralose].

Synaptic processes in the bulbar and pontine reticulospinal neurons (RS-neurons) were studied in chloralose-anesthetized cats during startle reaction to somatic stimulation ("spino-bulbo-spinal"--SBS-reflex). Excitatory PSPs were found to be a main type of synaptic responses in the RS-neurons; they were oligosynaptic (including monosynaptic) and polysynaptic. The comparison between synaptic responses of RS-neurons and SBS-reflexes showed that the polysynaptic EPSPs were most effective in generation of a SBS descending volley. It was also shown that about half of bulbar and pontine RS-neurons were simultaneously involved in suprasegmental relay of the SBS-reflexes. Conduction velocities in their axons ranged between 30 and 98 m/s (mean 64.5 +/- 16.5 m/s). Some functional features of the reticular centre of startle reaction are discussed.

Anesthesia, General↗
PubMedDate not supplied

Elevated cerebellar cyclic GMP levels during the deltamethrin-induced motor syndrome.

Adult male Porton albino rats received deltamethrin (0.5--40.0 mg/kg IP) or glycerol formal solvent IP. Their behaviour was observed during the subsequent 110 minutes and the incidence and latency of salivation, tremor and incoordination and spontaneous choreiform episodes were noted. Cyclic GMP levels in the cerebellum were determined by radioimmunoassay at various times after deltamethrin administration. The development of the motor syndrome was dose-dependent and followed a specific time course. The threshold dose for profuse salivation and tremor and incoordination was 2.5 mg/kg IP, and for spontaneous choreiform episodes, 5.0 mg/kg IP. The latency of tremor and incoordination decreased significantly as the deltamethrin dose was increased. The first significant increase in cyclic GMP levels in the cerebellum was at 70 minutes, which was 10 minutes after the mean latency of tremor and incoordination. The levels increased further at 100 minutes which was approximately 20 minutes after the mean latency of spontaneous choreiform episodes. Deltamethrin did not have a dose-dependent effect on cyclic GMP levels. The results suggest that deltamethrin changes cerebellar cyclic GMP levels indirectly.

Animals↗
PubMed1982

Central and peripheral nervous system effects of metals: a survey.

There are several categories of neurologic dysfunction which have been associated with metal intoxication. Many examples of case histories or animal studies where toxicity by metals has produced clinical manifestations and pathophysiologic changes similar to those found in certain primary neurological disorders have been reported. It is easy to make a diagnosis of metal intoxication in a subject whose work history and circumstances of exposure to specific substances is known. Observation of defined safety standards and time weighted averages for a work day in conjunction with environmental monitoring procedures are intended to reduce risk of undue absorption of known potential intoxicants. However, when a patient is seen by a physician and a probable neurological diagnosis is to be made in the absence of a detailed life-work history, the possible relationship to previous or current intoxication may be overlooked. This communication will review several neurological syndromes which have been found in association with metal accumulation.

Behavior↗
PubMed1983

[Neuroendocrine modulation of haloperidol-induced catalepsy].

Evidence has been accumulated implicating sex hormones as possible modulators of extrapyramidal motor function. In the present study we have investigated the effects of estrogens, progesterone, testosterone, prolactin and calcitonin on behavioral parameters related to nigro-striatal dopaminergic system, such as haloperidol-induced catalepsy in male rats. It was found that 7-days estradiol benzoate treatment (5 micrograms/rat/day) significantly increases haloperidol-induced catalepsy, suggesting a possible antidopaminergic activity of estrogens. On the other hand, prolactin facilitates nigro-striatal dopaminergic transmission. Interestingly, 7 day treatment with medroxy-acetate progesterone (MAP, 5 mg/Kg, i.p.) brings about a trend to a decrease in haloperidol-induced catalepsy, while no significantly effect was observed following acute MAP administration at the same dose. So, it is tempting to speculate that chronic progestinic treatment may result in an increase in dopaminergic tonus. Testosterone, acutely administered (5mg/kg.s.c.) induces changes similar to those observed following progesterone administration. Finally, also calcitonin is able to influence haloperidol-induced catalepsy by markedly increasing it.

Androgens↗
PubMed1984

[Clinico-immunologic evaluation of the sequelae of closed craniocerebral injuries].

Sixty-four patients were examined clinically and immunologically at a long-term period following craniocerebral trauma. In patients with a history of head trauma impaired adaptation mechanisms were shown to underlie the neurologic disorders, which was reflected in changes in the natural immunity system. The severity and duration of natural resistance impairments were correlated with the gravity of clinical manifestations. The study of the time-course of natural resistance parameters allows the objective evaluation of the degree of central nervous system recovery following closed craniocerebral trauma.

Acute Disease↗
PubMed1984

Calciotropic hormones as possible modulators of rat extrapyramidal motor system.

In the present study the Authors have investigated the effects of chronic treatment with calcitonin and parathyroid hormone on rat extrapyramidal motor system. Although it seems that calcitonin and parathyroid hormone may act as a neuromodulators at extrapyramidal level by influencing, directly or indirectly, nigro-striatal dopaminergic transmission, the role played by calcium metabolism at peripheral level, is not clear. In order to put light on this matter, different groups of animals were treated with calciotropic hormones plus EDTA, which is a drug that blocks Ca2+ ions, or EDTA alone. The results obtained don't show any change either in nigral GAD activity or apomorphine induced hyperactivity in EDTA injected animals. Furthermore, EDTA doesn't seem to modify the effects of both PTH and ct, as shown by results obtained in animals treated with ct or PTH plus EDTA.

Animals↗
PubMedDate not supplied

The purely neuroleptic effects and its relation to the "neuroleptic threshold".

Since 1953 when for the first time author pointed at correlation between clinical-neuroleptic effectiveness and the extrapyramidal system, more than 50,000 investigations with 30 different short-term and long-term neuroleptics have been carried out on approximately 850 schizophrenics whose extrapyramidal fine movements were tested according to author's handwriting-test. The results have been comprehended by author as follows: 1. the neuroleptic threshold; 2. the neuroleptic potency according to the neuroleptic threshold; 3. the neuroleptic therapeutic range; 4. the disposition to the neuroleptic threshold-dosage.

Basal Ganglia Diseases↗
PubMed1984

[Role of the reticular formation in regulating movement. Several intrareticular mechanisms and functional properties of the reticulospinal system].

The aim of this work was to obtain further information about some mechanisms of participation of the reticular formation and its descending reticulo-spinal systems in the regulation of the motor functions of the spinal cord. Following questions were studied: membrane characteristics of the reticulospinal neurons with slow and rapid axonal conduction and peculiarities of monosynaptic control influences on these groups of reticulospinal neurons from the motor cortex; characteristics of population responses of the reticular formation with respect to its ability to discriminative sensory and motor functions; reactions of the reticular formation neurons correlated with learned movements. Data obtained evidence that the reticular formation can be involved in control of specialized motor actions. Functional significance of the specific properties of the reticular formation as well as further prospects of exploration of its functional organization are discussed.

Animals↗