Factors that predict individual vulnerability to amphetamine self- administration
Article Abstract:
The effects of drug addiction vary from one individual to another. This variability must be taken into consideration when conducting animal studies. In previous studies where low doses of drugs were used, individual differences were seen when rats were allowed to self-administer drugs. In this study, variations in patterns of self-administration of amphetamine, a neurological stimulant, were predictable according to identifiable behavioral traits of the individual rats. Rats were grouped as high responders (HR) or low responders (LR), based on their level of activity after being exposed to the stress of a new environment. The rats were then each given an injection of amphetamine. The level of activity was higher in those rats that were more active after exposure to the new environment. If rats were then injected with four doses of amphetamines, the HR rats showed the same level of locomotor response, while LR rats showed increased activity, up to the level of the HR rats. The rats were implanted with intravenous cannulas (tubes inserted into the veins to allow passage of fluids), so they could in effect self-administer the amphetamine. Initially, the HR rats gave themselves more doses of amphetamines than LR rats, but after four injections of amphetamines, there was no difference in the degree of self-administration of amphetamines between the two groups. This study shows that behavioral characteristics can influence an individual's response to drugs and that continued exposure to drugs can negate these differences.
Publication Name: Science
Subject: Science and technology
ISSN: 0036-8075
Year: 1989
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Growth factors sculpt the synapse
Article Abstract:
Brain studies show synapse development is affected by transforming growth factor-beta, a signaling molecule. Growth factors in the marine mollusk Aplysia californica have shown to change the development patterns of impulse transmission between sensory and motoneurons.
Publication Name: Science
Subject: Science and technology
ISSN: 0036-8075
Year: 1997
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Spontaneous Activity: Signal or Noise?
Article Abstract:
Spontaneous neural activity in awake baby ferrets, before their eyes open, was studied. The results may lead to greater understanding of developmental neurology.
Publication Name: Science
Subject: Science and technology
ISSN: 0036-8075
Year: 1999
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