INVESTIGADORES
BERNABEU Ramon Oscar
congresos y reuniones científicas
Título:
Nicotine effects on epigenetic factors and vulnerability.
Autor/es:
R. BERNABEU.
Lugar:
VALPARAISO
Reunión:
Conferencia; International worshop ?Motivated behavior, stress and addiction: from molecules to behavior?; 2012
Resumen:
Nicotine abuse is a public health problem
of international scope, with enormous medical and socioeconomic consequences.
Recent findings suggest that nicotine possesses similar neuroactive properties
as the highly addictive psychomotor stimulants such as cocaine and
amphetamine. Similar to these drugs of
abuse, nicotine addiction is thought to be due to the activation of the
mesocorticolimbic pathway. In abstinent drug addicts, the likelihood of relapse
is high and limits the effectiveness of therapeutic interventions even after
successful detoxification. Traditionally, the animal model of choice used
to examine relapse to drug-seeking behavior has been the self-administration
reinstatement procedure. However, place
conditioning (PC) has been used to measure the rewarding as well as the
aversive properties of drugs of abuse.
The PC paradigm measures the incentive motivational properties of
stimuli that become associated with drug effects through classical
conditioning. The most favorable hypothesis at present suggests that the
dependence to a psychoactive substance results of associative and adaptive
processes in the mesocorticolimbic pathway, after repetitive exposure to the
substance. It was suggested that these
associative and adaptive mechanisms involve processes of learning and
memory. This hypothesis implies the
modification of the efficacy of numerous synapses, needing the action of
transcription factors, synthesis of new proteins and transcription of the
corresponding genes. We are trying to
characterize some long-term mechanisms activated or repressed by nicotine after
a CPP protocol. After the CPP, we study the transcription and the epigenetic
factors. Our studies suggest that certain
transcription factors participate after CPP, such as during reward and relapse,
while during nicotine withdrawal epigenetic factors seem to play a more
important role. Moreover, in nicotine
reward and relapse groups, structures involved in memory consolidation are
activated, suggesting that limbic structures modulate or participate in the
establishment and maintenance of nicotine dependence.