Behavior learning

The notion that colors, flavors, and other common food additives could adversely affect children s behavior was widely publicized in the 1970s. According to Feingold (1974), 40-70% of children who exhibited impulsive behavior, learning disabilities, short attention spans, and other symptoms characteristic of attention deficit hyperactivity disorder or ADHD (formerly called hyperkinesis, hyperactivity, or minimal brain dysfunction) showed dramatic improvement when placed on diets without food dyes and other common additives. 

Stevens, L.J., Zentall, S.S., Abate, M.L., Kuezek, T., and Burgess, J.R. (1996) Omega-3 fatty acids in boys with behavior, learning, and health problems. Physiol Behav 59 915-920. 

With exposures to drugs severe enough to kill nerve cells or parts of cells, longterm, often permanent, deficits in sensory processes, motor function, behavior, learning capacity, and memory can occur. Since neurons do not reproduce, recovery of lost function occurs only if the remaining nervous system can take over the functions of the cells that were killed. Less severe exposures will modify function, often profoundly, until the drug is eliminated from the body. In most cases, normal behavior returns, and there may be no evidence of chronic consequences. With repeated exposures to some substances, however, the consequences may take on an irreversible quality. 

The cerebral cortex of the brain is an approximately continuous, homogenous neural medium, which is molded (or rutted ) into preferred tracks of neural transmission by imprinting and by repeated activity (i.e., behavioral learning). Within this system, there exists a relatively discrete series of dimensions ("levels ) within which recurrent circular operations stabilize existing patterns (1) the sensory-motor loop, representing interaction with the physical/behavioral space outside, and (2) an internal behavior loop, which operates even in isolation from the... 

The protein kinase C (PKC) signaling pathway has been associated with modulation of A-methyl-D-aspartate (NMDA) receptor activity, motor behavior, learning, and memory, all of which are severely impaired in intoxication with sarin and similar OPs. There was a reduction in the immunoreactivity levels of betall-PKC and Zeta-PKC in the frontal cortex (up to 24 h), and in the striatum (up to 5 days) post-sarin exposure, in contrast to the increase in the immunoreactivity of both enzymes in the hippocampus or thalamus, following a IxLDso exposure to sarin. These observations suggest a role for both conventional and atypical PKC isozymes in OP-induced neuropathy in the rat and further support their role in cell death (Bloch-Shilderman et al., 2005). 

Fig. 6. Radial arm maze (a) and T-maze (b). Mazes are classic tools for the assessment of behavior, learning and memory. Modern mazes are often automated using photocells and video monitoring. (From http //www.colinst.com with permission.)...

Impacts on brain function (including changes in behavior, learning and memory) have been observed in rodents exposed to Penta- BDE products either in the womb (in utero) or soon after birth (post-natally). Some of these effects persisted and worsened into adulthood. The lowest dose that produced developmental neurotoxic effects in these studies is 0.8 mg/kg" (p.21). 

Modification in behavior patterns involves a wide variety of effects, such as alterations in migratory behavior, learning ability, feeding behavior, predator avoidance, and so forth. A few examples will illustrate some of the kinds of problems that pollutants may cause as a resirlt of behavioral modification. 

Gabriel, M., Foster, K., and Orona, E., 1980, Interation of laminae of the cingulate cortex with the anteroventral thalamus during behavioral learning. Science 208 1050-1052. 

Stress assay Wing expansion behavior Learning and memory behavior Life span Pain reaction Phototaxis Retinal degeneration Seizure and tremor behavior Visual discrimination... 

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