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Eric C. Dumont"Drugs of abuse-induced synaptic adaptation in the Bed Nucleus of the Stria Terminalis (BST)"

Abstract :

The bed nucleus of the stria terminalis (BST) is a cluster of about 10 nuclei surrounding the caudal part of the anterior commissure.
An increasing amount of anatomical and behavioral observations suggest the BST as part of a cortico-striato-pallidal system that coordinates autonomic, neuroendocrine, and behavioral functions particularly with regards to energy balance, defense, and reproduction. The efferent pattern of several BST nuclei suggests a role in elaborating responses to seek (motivation systems), consume (somato-motor systems involved in chewing, licking, swallowing), digest, and eliminate (neuroendocrine and autonomic control of visceral systems) food. The role of the BST in ingestion behaviors (such as seeking for palatable food) could contribute to the positive reinforcement aspects of addictive behaviors (food seeking or taking). In addition, the aversive aspect of drug withdrawal also triggers drug seeking in dependent animals, and the BST is a key contributor to this negative reinforcing effect of drugs.
The lateral region of the anterior BST (alBST), particularly its ventral aspect, is an important component of the brain motivation pathways. The alBST sends a monosynaptic excitatory output to dopamine neurons in the ventral tegmental area (VTA). My most recent work demonstrates that drugs of abuse such as morphine or cocaine produce synaptic adaptation both at excitatory and inhibitory synapses within the alBST. Indeed, increased excitatory transmission onto alBST might influence the reward pathways, perhaps by synaptic activation dopamine neurons. Conversely, increase in GABAA transmission during withdrawal might attenuate alBST outputs and contribute to the withdrawal-induced inhibition of dopamine neurons.

Selected publications

Éric C. Dumont, Beth K. Rycroft, M. Jaione Maiz, and John T. Williams. Morphine produces excitatory neuroplasticity in a circuit specific way in the bed nucleus of the stria terminalis. Submitted.2006
Éric C. Dumont, Gregory P. Mark, Sarah Mader and John T. Williams. Self-administration enhances excitatory synaptic transmission in the bed nucleus of the stria terminalis. Nat. Neurosci., 2005, 8(4), 413-414.
Éric C. Dumont and John T. Williams. Noradrenaline triggers GABAA-inhibition of bed nucleus of the stria terminalis neurons projecting to the ventral tegmental area. J. Neurosci. 2004, 24(38): 8198-204.

François Georges