Neurobehavioral Effects of Acute Exposure to Aromatic Hydrocarbons

This article reports the results of neurobehavioral tests on representative aromatic constituents, specifically C9 to C11 species. The testing evaluated effects in several domains including clinical effects, motor activity, functional observations, and visual discrimination performance. Exposures ranging from 600 to 5000 mg/m3, depending on the molecular weights of the specific aromatic constituents, produced minor, reversible effects on the central nervous system (CNS), particularly in the domains of gait and visual discrimination. There was little evidence of effects at lower exposure levels. There was some evidence of respiratory effects at 5000 mg/m3 in 1 study, and there were also minor changes in body weight and temperature. The CNS effects became less pronounced with repeated exposures, corresponding to lower concentrations in the brain of 1 representative substance, 1,2,4-trimethyl benzene (TMB). At high exposure levels, the alkyl benzenes apparently induced their own metabolism, increasing elimination rates.

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Neurobehavioral Effects of Acute Exposure to Isoparaffinic and Cycloparaffinic Hydrocarbons

International Journal of Toxicology ◽

10.1177/1091581811423844 ◽

2011 ◽

Vol 30 (6) ◽

pp. 715-734 ◽

Cited By ~ 9

Author(s):

Richard H. McKee ◽

J. H. C. M. Lammers ◽

H. Muijser ◽

David E. Owen

Keyword(s):

Central Nervous System ◽

Visual Discrimination ◽

Discrimination Performance ◽

Clinical Effects ◽

Occupational Exposure Limits ◽

Exposure Limits ◽

Discrimination Testing ◽

Effect Level ◽

Neurobehavioral Effects ◽

Cns Effects

This article reports neurobehavioral tests in rats with C5-C11 isoparaffinic and cycloparaffinic hydrocarbons. Testing, conducted shortly after exposure, evaluated the effects in several domains including clinical effects, motor activity, functional observations, and visual discrimination performance. Isopentane and cyclopentane did not produce any evidence of acute central nervous system (CNS) effects at levels up to 20 000 mg/m3. A C6/C7 mixed cycloparaffinic solvent produced minor, reversible changes in latency to response in visual discrimination testing at 14 000 mg/m3; the no-effect level was 4200 mg/m3. A C8 isoparaffin produced no effects at 14 000 mg/m3, the highest level tested. A C9/C11 isoparaffinic solvent produced minor acute CNS effects at 5000 mg/m3, with 1500 mg/m3 as the no-effect level. A C10 cycloparaffinic solvent did not produce any statistically significant CNS effects at 5000 mg/m3. These studies were designed to provide data that may be useful in setting occupational exposure limits for C5-C11 isoparaffinic and cycloparaffinic hydrocarbons.

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Neurobehavioral Effects of Acute Exposure to Normal (n-) Paraffins

International Journal of Toxicology ◽

10.1177/1091581810385148 ◽

2011 ◽

Vol 30 (1) ◽

pp. 47-58 ◽

Cited By ~ 11

Author(s):

J. H. C. M. Lammers ◽

H. Muijser ◽

D. E. Owen ◽

B.M. Kulig ◽

R. H. McKee

Keyword(s):

Molecular Weight ◽

Central Nervous System ◽

Visual Discrimination ◽

Discrimination Performance ◽

Clinical Effects ◽

Compelling Evidence ◽

Effect Level ◽

Neurobehavioral Effects ◽

Cns Effects ◽

Metabolic Induction

This article reports the results of neurobehavioral tests on C5-C10 normal paraffinic constituents (n-paraffins). Shortly after exposure, effects were evaluated in several domains including clinical effects, motor activity, functional observations, and visual discrimination performance. The representative C5 n-paraffin, n-pentane, did not produce any evidence of acute central nervous system (CNS) effects at levels up to 20 000 mg/m3. Similarly, there was no compelling evidence that n-octane (C8) produced CNS effects at 14 000 mg/m3, the highest concentration tested. n-decane (C10) produced minor, reversible acute CNS effects at 5000 mg/m3, with 1500 mg/m3 as the no-effect level. Consistent with literature data, there seemed to be a relationship between increasing molecular weight up to C10 and acute CNS effects. However, the CNS effects were reversible. Repeated exposures did not provide evidence of metabolic induction.

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Neurobehavioral Effects of Cyclohexane in Rat and Human

International Journal of Toxicology ◽

10.1177/1091581809345534 ◽

2009 ◽

Vol 28 (6) ◽

pp. 488-497 ◽

Cited By ~ 14

Author(s):

J. H. C. M. Lammers ◽

H. H. Emmen ◽

H. Muijser ◽

E. M. G. Hoogendijk ◽

R. H. McKee ◽

...

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Discrimination Performance ◽

Internal Exposure ◽

Psychomotor Speed ◽

Significant Treatment ◽

High Exposure ◽

Observational Measures ◽

Human Volunteers ◽

Neurobehavioral Effects

The neurobehavioral effects of inhaled cyclohexane in rats and humans are investigated to define relationships between internal doses and acute central nervous system effects. Rats are exposed for 3 consecutive days at target concentrations of 0, 1.4, 8, and 28 g/m3, 8 h/d. Measurements include standardized observational measures, spontaneous motor activity assessments, and learned visual discrimination performance. Cyclohexane concentrations in blood and brain are measured to assess internal exposure. Human volunteers are exposed for 4 hours to 86 or 860 mg/m3 in 2 test sessions. Neurobehavioral effects are measured using a computerized neurobehavioral test battery. In rats, there are slight reductions in psychomotor speed in the high-exposure group but minimal central nervous system effects. In humans, there are no significant treatment-related effects at the levels tested.

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Effects of serial disconnection of striate and temporal cortex on visual discrimination performance in monkeys.

Journal of Comparative and Physiological Psychology ◽

10.1037/h0027641 ◽

1969 ◽

Vol 68 (1, Pt.1) ◽

pp. 139-146 ◽

Cited By ~ 8

Author(s):

Sandra L. Reitz

Keyword(s):

Visual Discrimination ◽

Temporal Cortex ◽

Discrimination Performance

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Aluminium hydroxide implants on the inferotemporal cortex of the monkey: Their mode of influencing visual discrimination performance

Experimental Neurology ◽

10.1016/0014-4886(71)90118-x ◽

1971 ◽

Vol 33 (3) ◽

pp. 459-474 ◽

Cited By ~ 9

Author(s):

D. Gautrin ◽

G. Fenton ◽

G. Ettlinger

Keyword(s):

Aluminium Hydroxide ◽

Visual Discrimination ◽

Discrimination Performance ◽

Inferotemporal Cortex

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Confidence in perceptual decision-making is preserved in schizophrenia

10.1101/2019.12.15.19014969 ◽

2019 ◽

Cited By ~ 1

Author(s):

Nathan Faivre ◽

Matthieu Roger ◽

Michael Pereira ◽

Vincent de Gardelle ◽

Jean-Christophe Vergnaud ◽

...

Keyword(s):

Visual Discrimination ◽

Discrimination Performance ◽

Perceptual Decision Making ◽

Task Execution ◽

Bayesian Analyses ◽

Functional Deficits ◽

Evidence Accumulation ◽

Narrative Assessment ◽

Mental Operations ◽

Healthy Participants

AbstractMetacognition is the set of reflexive processes allowing humans to evaluate the accuracy of their mental operations. Deficits in synthetic metacognition have been described in schizophrenia using mostly narrative assessment and linked to several key symptoms. Here, we assessed metacognitive performance by asking individuals with schizophrenia or schizoaffective disorder (N=20) and matched healthy participants (N = 21) to perform a visual discrimination task and subsequently report confidence in their performance. Metacognitive performance was defined as the adequacy between visual discrimination performance and confidence. Bayesian analyses revealed equivalent metacognitive performance in the two groups despite a weaker association between confidence and trajectory tracking during task execution among patients. These results were reproduced using a bounded evidence accumulation model which showed similar decisional processes in the two groups. The inability to accurately attune confidence to perceptual decisions in schizophrenia remains to be experimentally demonstrated, along with the way such impairments may underpin functional deficits.

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Heterogeneity of the mechanisms of action of antidepressants

V M BEKHTEREV REVIEW OF PSYCHIATRY AND MEDICAL PSYCHOLOGY ◽

10.31363/2313-7053-2021-1-11-17 ◽

2021 ◽

pp. 11-17

Author(s):

V. L. Kozlovskii ◽

M. Yu. Popov ◽

D. N. Kosterin ◽

O. V. Lepik

Keyword(s):

Molecular Mechanisms ◽

Therapeutic Response ◽

Pathological Process ◽

Clinical Activity ◽

Clinical Effects ◽

Drug Induced ◽

Neuronal Interactions ◽

Neurophysiological Studies ◽

The Central Nervous System ◽

Monoamine Receptors

The article discusses the heterogeneous mechanisms of the pharmacodynamics of antidepressants that underlie the therapeutic response. Sharing the similar clinical activity, antidepressants determine the development of drug-induced homeostasis by means of different molecular mechanisms (selective or nonselective blockade of monoamine reuptake, inhibition of monoamine oxidase, blockade of certain monoamine receptors). However, an increase of serotonin and other monoamines concentrations in the synapses of the central nervous system is only the initiating factor in the development of specific clinical effects. The latter are probably determined by other neurochemical effects, including changes in the density of postsynaptic receptors and an increase in the synthesis of neurotrophic factors. However, the primary mechanisms that increase monoamine concentrations in the synapses might not always “work properly”, leading to the lack of efficacy of the initial antidepressant, while the probability of the therapeutic response to the subsequent antidepressant remains rather high. Thus, the efficacy of an antidepressant may depend on the baseline differences in the neurochemical state contributing to the pathological “depressive” homeostasis. The heterogeneous neurochemical effects of antidepressants can determine the dissociation of existing neuronal interactions, leading to the development of the new — druginduced — homeostasis. At the same time, it is possible that stimulation of general neurotrophic processes by antidepressants may contribute to the progression and chronicity of pathology due to the ambiguous influence on certain stages of the pathological process. This determines the significance of neurophysiological studies of central disturbances in depression and search of fundamentally new neurochemical targets for the treatment of depressive states associated with various mental disorders.

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Training protocol for touchscreen-based visual discrimination in mice

10.31234/osf.io/whkg5 ◽

2020 ◽

Author(s):

Kazuhiro Goto ◽

Yuya Hataji

Keyword(s):

Visual Discrimination ◽

Reinforcement Schedule ◽

Discrimination Performance ◽

Magazine Training ◽

Stimulus Position ◽

Continuous Reinforcement Schedule ◽

Continuous Reinforcement ◽

Contrast Discrimination ◽

And Behavior ◽

Training Protocol

Automated touchscreen-based tasks are increasingly being used to explore a broad range of issues in learning and behavior in mice. Researchers usually report how they train mice before acquiring the target task concisely, and shaping protocols at this stage are typically flexible. In this report, we described a training protocol, developed in our laboratory, for mice acquiring a simultaneous discrimination performance using visual stimuli. C57BL/6N mice were first given magazine training. Nosepoke responses were then authoshaped and maintained on a continuous reinforcement schedule. Self-start response was then introduced in order to measure response time to complete each trial. The stimulus position was also varied across trials. We finally examined the contrast discrimination performance. Mice were tested with four different contrast ratios. Target stimuli were white and black targets and the brightness of distractors had values between targets and background. All mice successfully went through all training stages, confirming that this training protocol is promising for shaping appropriate discriminative behaviors in mice.

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