Behavior function

ADHD because cognitive functions known to be affected in this disorder, namely working memory and inhibitory control, are sensitive to manipulations of D1 receptor-mediated dopamine transmission [1]. Thus, the tonic component might be more critical for the behavioral functions of the FC. 

Many tests have been devised to provide quantitative measures of behavioral disturbances caused by neurotoxic chemicals. Tests have been devised that assess the effects of chemicals on four behavioral functions (D Mello 1992). These are sensory, cognitive, motor, and affective functions. However, because the entire nervous system tends to work in an integrated way, these functions are not easily separable from one another. For example, the outcome of tests focused on sensory perception by rats may be influenced by effects of the test chemical on motor function. 

These are four monoamines synthesized and seereted within many mammalian tissues, ineluding various regions in the brain, sympathetic nervous system, enlero-chromafhn cells of the digestive tract, and adrenal mednlla. These biogenic amines (indoleamine and catecholamines — dopamine, norepinephrine, and epinephrine) are synthesized within the cell from their precursor amino acids and have been associated with many physiological and behavioral functions in animals and humans. 

Behavioral Function in Adults. Neurobehavioral testing has revealed effects in adults at PbB levels (i.e., 40-80 pg/dL) below those causing encephalopathy (>400 pg/dL). Evaluations of occupationally exposed adults include several affected parameters at PbB levels between 40 and 80 pg/dL. Disturbances in oculomotor function (saccadic eye movements) in lead workers with mean PbB levels of 57-61 pg/dL were reported in a study by Baloh et al. (1979) with follow-up by Spivey et al. (1980) and in a study by Glickman et al. (1984). Deficits in hand-eye coordination and reaction time were reported in 190 lead-exposed workers (mean PbB level, 60.5 pg/dL) (NIOSH 1974). Most of the workers had been exposed for between 5 and 20 years. A similar study, however, reported no differences... 

NIOSH. 1974. Evaluation of behavioral functions in workers exposed to lead. In Xintaras C, Johnson BL, De Groot 1, eds. Behavioral toxicology Early detection of occupational hazards. Cincinnati, OH US. Department of Health, Education and Welfare, National Institute for Occupational Safety and Health, 248-266. 

Lochry, E.A. (1987). Concurrent use of behavioral/functional testing in existing reproductive and developmental toxicity screens Practical consideration. J. Am. Coll. Toxicol. 6 433-439. 

Crichton Geriatric Rating Scale. The Crichton Geriatric Rating Scale test measures the level of behavioral function in elderly psychiatric patients using a five-point scale on 11 items. It rates either the present or the period within the last week and takes 5 to 10 minutes to complete. 

Mactutus CF. 1986. Early adrenal steroid influences on neural and behavioral function. Neurotoxicology 7(2) 77-94. 

Both male and female black-tailed deer, 0. h. columbianus, rub their foreheads on twigs and branches. Several studies have indicated that this behavior functions as visual and olfactory signposts [ 130]. A qualitative and quantitative... 

Frontotemporal dementias are characterized by gross structural changes in the frontal and anterior temporal lobes, metabolic disturbances, and involvement of certain subcortical structures as well (Ishii et al. 1998). Whereas in Alzheimer s disease the early cognitive disturbances are in memory, in frontotemporal dementias the early manifestations are in executive and behavioral function (Pfeffer et al. 1999 Varma et al. 1999). This relative cognitive distinction persists throughout the course of the two disorders (Pachana et al. 1996). Disinhibition and disorganization are common, and psychotic symptoms may be prominent in frontotemporal dementia. 

To further evaluate the role of CRH in both neuroendocrine and behavioral functions, a mammalian model of CRH deficiency has been generated by targeted mutation in embryonic stem cells (Mugha et al. 1995). CRH-deficient mice reveal a fetal glucocorticoid requirement for lung maturation. Postnatally, they display marked glucocorticoid deficiency and an impaired endocrine response to stress (Jacobson et al. 2000 Mugha et al. 1995). 

The part played by endogenous opioid systems in the regulation of these various physiological and behavioral functions has led to the experimental application of opiate antagonists in psychiatric disorders. This chapter focuses on autism and self-injury, which are two potential indications for opiate antagonists in pediatric populations. In adults, treatment with opiate antagonists has shown to be useful in the relapse prevention of alcoholism as part of a comprehensive treatment approach (Anton et ah, 1999, 2001). 

Monteiro-Musten, L., Firestone, P., Pisterman, S., Bennett, S., and Mercer, J. (1997) Effects of methylphenidate on preschool children with ADHD cognitive and behavioral functions./ Am Acad Child Adolesc Psychiatry 36 1407-1415. 

In undisturbed ecosystems, plant and herbivorous Insect populations coexist In a steady state condition dictated by external biological and physical factors (parasites, predators, precipitation, temperature, soil quality, etc.). But this balance is also regulated by myriads of very fundamental Interactions, many or even most of which are yet unknown, between the plant allelochemi-cals and the biochemical, physiological, and behavioral functions of the Insect herbivores ( 1). 

The primary approach currently used to detect and characterize potential neurotoxicants involves the use of animal models, particularly rodents. Behavioral and neurophysiological tests, often similar to the ones used in humans, are typically administered. The sensitivity of these measures to neurotoxicant exposure is widely accepted. Although it is often not possible to test toxicant effects on some higher behavioral functions in animals (e.g., verbal ability, cognitive flexibility), there are other neurobehavioral outcomes such as memory loss, motivational defects, somatosensory deficits, and motor dysfunction that can be successfully modeled in rodents. These behaviors are based on the ability of the nervous system to integrate multiple inputs and outputs, thus they cannot be modeled adequately in vitro. Although the bulk of neurotoxicity data has been collected in rodents, birds and primates are also used to model human behavioral outcomes. 

The presence of elements other than hydrogen and carbon in organic molecules greatly increases the diversity of their chemical behavior. Functional groups consist of specific bonding configurations... 

Target of pathway Receptor Physiological effect Behavioral function... 

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