Effect of a single dose of cocaine

2001/05/31 Galarraga Aiestaran, Ana - Elhuyar Zientzia

• Anatomia/Fisiologia

On the other hand, scientists do not know much about the neurological bases of addiction, for example, a mechanism that generates a long-term or permanent craving for a drug has not yet been identified. Some researchers believe that this mechanism is related to the plasticity of neurons that release dopamine. It seems that, due to the constant effect of addictive drugs, neural connections in this area are reinforced and increases the minimum concentration that triggers the mechanism.

In this week's journal Nature, a group of researchers from the University of California, led by Bonci, has published a work with mice. This is the first in vivo work on dependence related to the promotion of neurons that secrete dopamine. During this study, a mouse group was given cocaine and another group was given a saline solution. Subsequently, the response of the receptors of both substances in the brain area related to dopamine was analyzed and the relationship between the responses of both types of receptors was calculated. The fact that there is a change in this relationship shows that activity in that area of the brain has been encouraged.

The result of the study was clear: the researchers did not expect the effect of the dose of cocaine to persist so much, but they saw that the only dose of cocaine had promoted the activity of this brain area for 5-10 days. In addition, some received a second dose and the response was immediate. This shows that neurons, thanks to the first dose, were prepared to respond.

This research does not fully clarify the mechanism of chronic dependence, but it helps to understand the effect of drugs and the behavior of drug addicts.